23230028001 refrig trouble hooting manual

8/1/2019 23230028001 Refrig Trouble Hooting Manual

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2506 South Elm StreetGreenville, IL 62246

www.enertechmfg.cominfo@enertec hmfg .com

Refrigeration/ TroubleshootingManual

Table o f Contents:

Section 1: Geothermal RefrigerationCircuitsOverview ................................................................ 2Water-to-A ir Refrigerant Circuit ........................... 3

Refrig. Ckt. Component Op eration .................... 3Wate r-to -Water Refrige rant Circu it ..................... 5Split System Circuit ................................................ 6Co mbinat ion Unit Refrigera tion Circuit .............. 6Hea ting Op era tion ................................................ 7Cooling Operat ion ................................................ 8Summary ................................................................ 9

Sec tion 2: Hea t of Extrac tion/ Hea t ofRejectionOverview .............................................................. 10

Performanc e Da ta .............................................. 10Formulas ............................................................... 12Examples .............................................................. 13

Sec tion 3: Superheat/ Subcoo lingOverview .............................................................. 15Definitions ............................................................. 15Chec king Supe rheat a nd Subc oo ling.............. 15Pressure/ Tem pera ture Cha rt R-410A ................. 16Pressure/ Tem pera ture Cha rt R-22 ..................... 17Superhea t/ Subcoo ling Measurements ............ 18

Putting It All Together .......................................... 19Superheat/ Subc ooling Tab les ........................... 20Examples ......................................................... 21-22

Sec tion 4: Desuperheater OperationOverview .............................................................. 23Refrigerant Circuit ............................................... 23Desuperheate r Cut-Awa y .................................. 24

Rev.: 10 Jun 2010-AP/ N: 23-23-0028-001

Append ix A: Troub leshooting FormsWater-to -Air Refrigerant Circuit ......................... 25Wate r-to-Water Refrige rant Circuit ................... 25Comb o Unit - Hea ting/ Cooling Forced Air ...... 26

Comb o Unit - Wate r Hea ting Mode.................. 26Notes..................................................................... 27

Guide Revision Table:Date By Page Note

10 Jun, 2010 AV 2,5-925-26

Upd ated Circuit DiagramsRev ised Troub leshoot ing Form

25 Ma y, 2010 AV 7,26 Revised Combo Ref. Diagram

06 Ap r, 2010 AV 25-26 Troub leshoot ing Form s Rev ised

24 July, 2009 DS All M ino r fo rm atting up da te s

21 Aug , 2008 JH All First p ub lished


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2Enertech Manufac turing, LLC. Refrigera tion/ Troub leshooting Guide,10 Jun 2010-A

exchanger (water-to-water and water-to-a ir units) is connec ted to the g roundloop or open loop (well wa ter) system. The loa d heat exchange r is connec ted to thehydronic loa d (for examp le, rad iant floorheating) for water-to-wa ter units. The loa dhea t exchanger in a water-to-a ir unit is thea ir coil, which is c onnec ted to d uc t work.

Sp lit systems are w a ter-to-a ir heat p umps(see figure 6) with the com pressor sec tionand a ir hand ler sec tions in sep aratec ab inets. A c op per refrige rant line setc onnec ts the two pieces together.

Comb ination units p rovide a wa ter-to-airand a w ater-to-water heat p ump in the

sam e c ab inet (see figure 7). A c ombinationunit c an hea t or c oo l the a ir, and hea t wa terfor hydronic applications. Combination unitsa re no t set up to c hill wa ter.

Overview

Geo thermal heat pump s are ava ilab lein a variety of c onfigurations to provideflexib ility fo r insta llation in new constructionor retrofit a pp lications. Most c ommon inNorth America are pa ckag ed wa ter-to-air hea t pump s, which p rovide forced airhea ting a nd c oo ling . Packaged units (seefigure 1) have the c om pressor sec tion a ndthe a ir hand ler sec tion in the same cab inet.Other types of geo thermal hea t pumpsinc lude w a ter-to-water, sp lit system, andcom bination units.

Water-to-water heat p ump s hea t or chillwa ter instea d of hea ting o r coo ling the air

(see figure 5). The d ifferenc e b etw een awa ter-to-air and wa ter-to-wa ter hea t pumpis the loa d hea t exchanger. A sec ondwater-to-refrigerant c oil is substituted forthe a ir to refrigerant c oil. The source hea t

Figure 1: Water-to-Air Refrige ration Circuit

Sec tion 1: Geothermal Refrigeration Circuits

To suction line bulb

To suction line

AirCoil

Sucti

on

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode

Liquid line (heating)

Liquid line (cooling)

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax

Optional desuperheater

installed in discharge line

(always disconnect during

troubleshooting)

Condenser (heating)

Evaporator (cooling)

Condenser (cooling)

Evaporator (heating)

Suction

Discharge

1

3

24

5 6


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3Refrigerat ion/ Troub leshoot ing Guide10 Jun 2010-A

Enertech Manufacturing, LLC

Water-to-A ir Refrige rant Circuit

The w ate r-to-air geotherma l heat pum prefrigerant c ircuit is very simp le com paredto a ir source hea t p ump s. Defrost c yc leis not required , and a ll com ponents a reindoors in a single c ab inet. The mainc om ponents show n in figure 1 are thec om pressor (1), the a ir coil (2), the coa xia lhea t exchanger (3), the reversing va lve (4),the TXV or therma l expansion va lve (5), andthe filter d rier (6).

Compressor: The c ompressor (1) is the hea rt of the system. The c om pressorpump s refrige rant through the c irc uit, andincrea ses the pressure of the refrigerant.

Sinc e pressure and tem perature a re d irec tlyrela ted , when the pressure is increa sed , thetemperature is also increased. When thetem perature o f the refrige rant is ra ised to ahigher temp erature tha n the tempe ra tureof the a ir flow ing throug h the a ir c oil (2)in heat ing, heat is released to the a ir tohea t the build ing. Likew ise, when therefrigerant temperature is ra ised to a highe rtemp erature than the wa ter flow ing throughthe c oa xial hea t excha nger (3) in c oo ling,

hea t is released to the w a ter.


Enertec h Ma nufac turing uses CopelandSc roll compressors. A sc roll is an invo lutespiral which, when ma tc hed with a matingsp ira l sc roll form as shown in figure 2,ge nerates a series of c resc ent-shaped ga spo c kets be twe en the two mem be rs. Sc rollc om pressors work by mo ving one sp ira lelement inside another stationary spiral toc rea te a series of g as po c kets that bec omesma ller and increa se the pressure of the gas.

The la rgest openings are a t the outsideof the sc roll where the g as enters on thesuc tion side. As these gas poc kets arec losed off by the moving sp ira l they movetow ards the cente r of the sp ira ls andbecome smaller and smaller. This increases

the pressure on the gas until it rea chesthe cente r of the sp ira l and is d ischargedthroug h a p ort near the c ente r of the sc roll.Both the suc tion p roc ess (outer po rtion ofthe sc roll memb ers) and the d ischargeproc ess (inner portion) are c ontinuous.

The moving sc roll moves in an o rb itingpa th w ithin the sta tionary (fixed ) sc roll asit c rea tes the series of gas poc kets. Duringcompression, several pockets are being

compressed simulta neously, resulting in

Figure 2: Sc roll Operation

Compression in the

scroll is created by theinteraction of an orbiting

spiral and a stationary

spiral. Gas enters theouter openings as one

of the spirals orbits.

The open passages

are sealed off as gas isdrawn into the spiral.

As the spiral continues

to orbit, the gas iscompressed into

two increasingly

smaller pockets.

By the time the gas

arrives at the center

port, discharge pressure

has been reached.

Actually, during

operation, all six gaspassages are in various

stages of compression

at all times, resultingin nearly continuous

suction and discharge.


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a very smoo th p roc ess. By maintainingan eve n number (six in a Copeland Sc rollcompressor) of b alanc ed ga s po ckets onop posite sides, the c om pression forcesinside the sc roll wo rk to ba lance ea ch otherand red uce vibration inside the com pressor.

Single speed and two-sta ge (UltraTec h)sc roll c om pressors a re used in Enertec hMa nufac turing s p rod uc t line. The two-stagesc roll works exac tly like the single spee dsc roll shown in figure 2, but it ha s add itionalc om ponents, a solenoid va lve, and bypa ssports in the sc roll mec hanism. When thesoleno id va lve op ens the bypass ports asshown in figure 3, the c apac ity is red uc edto 67%, since part of the sc roll is bypassed .

67% - PORTS OPEN 100% PORTS CLOSED

Figure 3: UltraTec h Operation

Air Coil: The a ir coil (2), a refrigerant-to-airheat exchanger servers as the condenser inhea ting, and the e vap orator in cooling.

Coaxial Hea t Exchanger: The c oa xia l heatexcha nger (3), a w ater-to-refrige rant hea texchanger, serves as the evaporator inhea ting, and the c ond enser in coo ling.

Reversing Valve: The reversing va lve (4)provides the ab ility to switc h func tionsof the two hea t exchang ers, abo ve. Asshown in figure 1, the d ischa rge line fromthe c om pressor is a lways c onnec ted to thebottom of the reversing va lve. The c ente rconnec tion a t the top is always connec tedto the suc tion line from the com pressor.The o ther two connec tions allow the heat

pump to switch from hea ting to c oo ling.The norma l (non-energized ) mod e isheating. Therefo re, the d isc harge gas fromthe com pressor flow s to the a ir co il in thenon-energ ized mo de. When the reversingva lve soleno id is ene rg ized in c oo ling , theva lve switches to a llow the d ischarge gasfrom the com pressor to flow to the coaxialheat exchanger.

The reve rsing va lve is a p ilot-op eratedva lve, which means tha t the solenoidop ens a sma ll port, connec ting thec oppe r tubing from the b ottom p ort(d ischarge line from the com pressor) to theva lve c hamber. The high p ressure o f thed ischarge line fo rces the va lve to switch

from o ne mode to the othe r.

Thermal Expansion Valve (TXV): The TXV (5) me ters refrige rant to m ake sure tha t theprop er amount o f refrige rant is being fed tothe he at exchangers in orde r to m aximizethe c ondensing a nd evap ora ting func tions.The TXV is a lso imp ortant in keep ing liquidrefrigerant from rea ching the suc tion line ofthe c ompressor, which could dama ge thec ompressor. The TXV is designe d to opera te

b i-direc tiona lly in p ac kaged wa ter-to-airand wa ter-to-wa ter hea t p umps.

Diaphram

Valve Seat

Pin

4

4 = Liquid Pressure(opening force)

Figure 4: TXV Opera tion


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Figure 4 shows the op era tion of the TXV, andthe four forc es tha t affec t the op eration.The TXV has two c op per fittings forc onnec tion to the a ir c oil and c oa xial heatexcha nge r, as we ll as two sma ller cop perlines tha t a re used for me tering . One lineis c onnec ted to a bulb that is atta c hed tothe suc tion line of the c om pressor. The bulbis filled with refrigerant. As the suc tion linetemp erature c hanges, the b ulb pressurec hanges. The o ther line is c onne c tedd irec tly to the suc tion line. The bulb p ressure(forc e 1) pushes dow n on the d iaphragmas the bulb p ressure inc rea ses (suc tion linetemperature increases). When the pressurepushes dow n on the d iaphrag m, the pin(whic h is atta c hed to the d iap hrag m) is

pushed awa y from the va lve sea t, whichop ens the va lve.

The o ther line, c onnec ted d irec tly to thesuction line uses suction pressure (force 2) topush up on the d iap hragm a s the p ressureincrea ses. As the d iap hragm is pushed up ,the p in is pushed into the va lve sea t, c losing


To suction line

Load

Coax

Suction

SourceCoax

Discharge

Heating

Mode

Load

Coax

Suction

SourceCoax

Discharge

Cooling

Mode



Load

Coax

TXV

Filter Drier

Reversing

Valve

Source

Coax




troubleshooting)

Condenser (heating)


Condenser (cooling)


Suction

Discharge

Figure 5: Water-to-Water Refrige rant Circuit

the va lve. This relationship o f tem pera ture(bulb pressure) a nd pressure (suc tion line)c rea tes a ba lanc ing effec t, whic h c ausesthe va lve to me ter at 0F superhea t (seesec tion 3 for exp lana tion of superhea t).Sinc e it is important to make sure tha t liquidis not returning to the c om pressor, the va lvesp ring (force 3) is ad justed to foo l thevalve into b a lanc ing a t a higher supe rhea t(usua lly 10 to 12F). Force 4 (liqu id p ressure)is an op ening force .

Filte r Drier: The filter drier (6) functionsexac tly as its name implies. It filters anypartic les from the refrigerant system,and it pulls moisture from the system. It isextremely imp ortant tha t the filter drier is

chang ed any time the refrige rant c ircuitis open for a comp onent rep lac ement orrepa ir, espec ially fo r systems with R-410Arefrige rant. R-410A uses P.O.E. o il, whichis hygroscop ic (tendency of a ma teria lto absorb moisture from the a ir). Moistureconta minates the refrige rant c ircuit overtime, and must be avoided .


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Water-to-Water Refrige rant Circuit

The water-to-wa ter hea t pum p refrigerantc ircuit, as shown in figure 5, func tionsexac tly the same as the the w ater-to-a irrefrige rant c ircuit w ith one excep tion. Theair coil is rep laced by a sec ond coa xia lhea t exchange r. The source c oa x isthe same as the w ater-to-a ir unit coa x.How ever, the load coa x heats or chillswa ter instea d o f hea ting or coo ling the a ir.

Split System Refrige ration Circuit

Ge otherma l sp lit systems utilize a ll of thesam e co mp onents as a p ac kag ed w ate r-to -air hea t pump . The d ifferenc e is tha t

the c om pressor sec tion is rem ote from thea ir ha nd ler sec tion. An a dd itiona l TXV isreq uired , howeve r, since the a ir hand lerand c om pressor system we re no t d esignedto b e included in the sam e c ab inet. Therec ould b e va riab ility in systems due to line setleng ths, whic h requires a c oo ling TXV (a ir


To suction line

AirCoil

Suction

Coax

Discharge

HeatingMode

AirCoil

Suction

Coax

Discharge

CoolingMode

Common liquid line

AirCoil

Htg TXV

Filter Drier

Reversing

Valve

Source

Coax


installed in discharge line(always disconnect during

troubleshooting)

Condenser (heating)


Condenser (cooling)


Suction

Discharge

IN


To suction line

Clg TXVIN

Line set

Air Handler Compressor Section

Figure 6: Split System Refrigerant Circuit

ha nd ler) and a he a ting TXV (com pressorsec tion). If the TXV fo r the a ir ha nd ler is notfac tory insta lled , it is imp ortant to ma kesure tha t the TXV is insta lled in the c orrec tdirection, as shown in figure 6.

Combina tion Unit Refrige ration Circuit

The combination geotherma l hea t pumpis essent ially a w a ter-to-a ir and a wa ter-to-wa ter hea t pump in the same c ab inet (seefigure 7) . The addition of tw o c omponentsa llow s the hea t pump to switch betweenhea ting or coo ling the a ir, and hea tingwater. A sec ond reversing va lve (lab eled Direc tion Va lve ) de termines if the hea tpump will op erate as a w ater-to-a ir unit

or a water-to-wa ter unit. The 3-wa y va lveselec ts the c ond enser (air c oil or loa d coa x)in the heating mo de. The d irec tion va lveand 3-wa y valve work in conjunc tion toselect the a ppropriate hea t excha ngers.The reversing va lve works exac tly like thereversing va lve in a water-to-a ir hea t pump .


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To

dischargeline

To

suction

line

To suction

line bulb

To

suction

line

Liquid line (cooling)Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax

Optional desuperheaterinstalled in discharge line


troubleshooting)

Condenser (water heating)

Not used in cooling

Condenser (cooling)

Evaporator (heating) Suction

Discharge

Condenser (heating)


Not used in hot water mode

Direction

Valve

3-Way

Valve

Liquid line

(heating)

Figure 7: Combina tion Refrige rant Circuit

Hea ting Operation

For the purposes of d isc ussing the refrigerantc irc uit op eration in hea ting a nd c oo lingmod es, the w a ter-to-air c irc uit w ill be used .The o ther c onfigurations directly apply withminor terminolog y/c omp onent c hange s.

In hea ting mod e (see figure 8), thereversing va lve is not energized . The hightemperature, high pressure refrigerant gas

from the c om pressor flow s to the a ir coil. Asthe a ir mo ves throug h the a ir coil, the coo l(typ ica lly 70F) a ir causes the hot refrigerant(typ ic a lly 130 to 180F) to condense into aliquid. Thus, the a ir coil is the c ondenser inthe hea ting mod e.

After lea ving the a ir coil (cond enser),the refrigerant is approxima tely the

temperature of the lea ving a ir. Therefrigerant is within a few psi of being a t thesame pressure as it wa s a t the com pressord ischa rge line. This is the heating liquid line.The liquid line of a pac kaged unit c hang esloc ation, depending upon the mod e ofop era tion. It is a lwa ys loc a ted be tweenthe TXV and the c ond enser. How ever,since a geotherma l unit is a hea t pump ,the c ond enser ca n either be the a ir coil(heating) or co axia l wate r c oil (co oling).

At the TXV, the refrigerant is forced througha very sma ll opening, whic h c auses alarge pressure d rop . As ment ioned ea rlier,p ressure a nd tem perature a re d irec tlyrelated, so the tem perature also d rop s a fterthe TXV. At this point, the refrigerant is alow temperature liquid (typ ica lly 15 to 50F,depending upon loop temp erature).


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To suction line



AirCoil

TXV

Filter Drier

ReversingValve

SourceCoax




troubleshooting)

Condenser (heating)


Condenser (cooling)


Suction

Discharge

Figure 8: Hea ting Mode

The w arm wa ter (or wa ter/antifreezesolution) flow ing through the coaxial heatexchanger (typ ic a lly 30 to 60F) c auses thecold refrige rant to bo il off (evapora te)into a gas or va por. Thus, the coa x is the

evapo rato r in heating.

After lea ving the coa x (evap ora tor), therefrige rant is now approxima tely the sametempe rature as the w ate r entering thehea t pump. This low pressure gas ente rs thecom pressor, and the c yc le sta rts a llover aga in.

Prop er refrigerant m etering will insure tha tno liquid is returned to the com pressor.

Sec tion 3 discusses superheat a ndsubc oo ling, which a llow the technic ianto eva luate how we ll the c ondenser andevaporator are operating.

Cooling Operation

In coo ling m od e (see figure 9), thereversing va lve must b e ene rg ized . The high

temperature, high pressure refrigerant gasfrom the c om pressor flow s to the c oa xia lhea t excha nger. As the w ate r (or wate r/

antifreeze solution)flows through the c oa x,the coo l (typica lly 50 to 100F) wa ter causes

the hot refrigerant (typ ica lly 130 to 180F) toc ond ense into a liquid. Thus, the c oa x is thec ondenser in the cooling mod e.

After lea ving the c oa x (c ondenser),the refrigerant is approxima tely thetempe ra ture of the wa ter lea ving thec oa x. The refrigerant is within a few psi ofthe com pressor d ischarge line p ressure.

This is the cooling liquid line . The liquid lineof a p ac kag ed unit cha nges loc ation,depending upo n the mod e of op eration. Itis a lwa ys loc ated betw een the TXV and thec ond enser. How ever, sinc e a ge othe rmalunit is a hea t pump , the c ond enser caneither be the a ir co il (hea ting) o r coa xialwa ter co il (co oling).


9/28





To suction line



AirCoil

TXV

Filter Drier

Reversing

Valve

SourceCoax




troubleshooting)

Condenser (heating)


Condenser (cooling)


Suction

Discharge

Figure 9: Cooling Mode

At the TXV, the refrigerant is forced througha very sma ll ope ning, which c auses a la rgepressure d rop . Onc e aga in, since pressureand tempe ra ture a re d irec tly related , thetemperature a lso drop s a fter the TXV. At this

point, the refrigerant is a low tem peratureliquid (typ ica lly 35 to 45F, de pend ing up onreturn air tempe rature and air flow).

The warm a ir flow ing through the a ir coil(typ ica lly 70 to 80F) c auses the c oldrefrige rant to bo il off (evap orate ) intoa gas or vap or. Thus, the a ir coil is theevapora tor in coo ling.

After lea ving the a ir coil (evaporato r), therefrige rant is now approxima tely the sametempe ra ture a s the a ir entering the hea tpump. This low p ressure g as ente rs thec om pressor, and the cyc le sta rts a llover ag ain.

Summary

To summarize, refrigerant c ircuits ingeotherma l heat pump s ca n be c onfiguredfor pa ckaged wa ter-to-air, wa ter-to-wa ter,

sp lit systems or com bination w ater-to-a irand water-to-water units. All circ uits utilizea Copeland sc roll (single o r two-stage )com pressor, one or two wa ter-to-refrigerantcoa xial co ils, an a ir-to-refrigerant c oil, areversing va lve, a b i-d irec tiona l TXV, anda filter d rier. Combination units include ad irec tion va lve a nd a 3-wa y valve to switchcond enser opera tion.

The a ir coil op erates as the condenser inhea ting, and the evap orator in co oling.The source (loop) c oa x operates as thecond enser in coo ling a nd the evapo rato r inhea ting. Water-to-water units use a sec ondcoa x instea d o f the a ir coil.

The reve rsing va lve is energ ized in the c oo ling

mo de. The no n-energized mo de is hea ting.


10/28


Sec tion 2: Hea t of Extrac tion/ Hea t of Rejec tion

Overview

As ment ioned in sec tion 1, mostgeo therma l heat pumps are pac kag edwater-to-a ir heat pumps. Therefo re,the refrige rant c ircuit is eva c uated andcharged at the fac tory, and the re is noneed to c onnec t refrigerant ga ugesunless the technic ian ha s verified thatthere is a refrigerant c ircuit prob lem. Sinceconnec ting g aug es can cause a loss ofcharge and a ffec t performanc e, EnertechManufacturing recommends aga instconnec ting refrigerant ga uges at startup.There a re a number of chec ks that c anbe ma de a t sta rtup to ve rify pe rformancewithout c onnec ting refrige rant ga uges.

Hea t of extrac tion is a c a lcula tion o f theam ount of heat that is be ing extrac ted or ab sorbed from the wa ter or water/ anti-freeze solution b y the eva porato r (coa xia lheat e xchange r) in the heating mod e.Hea t of rejection is the a mount of hea tthat is be ing rejec ted to the w ater by thecondenser (c oa xial hea t excha nger) in thecoo ling mode. In add ition to measuring thetemperature rise or drop ac ross the a ir c oil,

calculating hea t of extrac tion or hea t ofrejec tion allow s the te chnic ian to ve rify thatthe hea t pump is performing ac cord ing tospecifica tions. If the c a lcula tion show s tha tthe hea t pump is performing p oorly, thenrefrige ra tion gauges ma y be required tofurther troub leshoo t the p rob lem.

Performance Data

Before d iscussing hea t of extrac tion (HE)/ hea t o f rejec tion (HR) c a lcula tions, thetec hnic ian should und erstand how to usethe performanc e da ta in the c ata log tocomp are the unit spec ifications to ac tualcalculations.

Figures 10 and 11 show performa nce d a tafor a typ ical 3 ton geothe rma l wa ter-to-

a ir hea t pum p. the highlighted columnsindica te HE and HR. In figure 10, HE is theamount of heat tha t is be ing extrac tedfrom the wa ter (for examp le, ground loop )by the refrigerant c ircuit. The c om pressorand fan p ow er (kW column) is used toop erate the refrigerant c ircuit. The heatdelivered to the spa ce (HC c olumn) equa lsthe HE from the water plus the wa ste hea tof the p ow er used for com pressor and fan.If the kW is converted to Btuh, and addedto the HE, the sum should equa l HC.

For example, in figure 10, a t 30F EWT, 9.0GPM a nd 70F EAT, the hea ting c apac ityis 30,700 Btuh. HE is 21,800 Btuh. If the kW(2.63) is conve rted to Btuh (2.63 x 3.412 =

8.97 MBtuh o r 8,970 Btuh), and added toHE, the result is HC. Therefore, if HE is within,10-15% of c a ta log performa nce, HC shoulda lso b e w ithin spec ifications. There is noneed to connec t refrige rant gauges if HE iswithin spec ifications.

In figure 11, HR is the amount o f hea t tha t isbeing rejecte d to the w ate r (for examp le,ground loop) by the refrigerant c ircuit. Thec ompressor and fan p ow er (kW column) is

used to operate the refrigerant c ircuit. Thehea t rejecte d from the spa ce (HR column)eq ua ls the hea t from the a ir (TC c olumn --amount of coo ling) p lus the waste hea t ofthe p ow er used for comp ressor and fan. Ifthe kW is converted to Btuh, and ad ded tothe TC, the sum should eq ua l HR.

For example, in figure 11, a t 90F EWT, 9.0GPM and 75F DB/63F WB (50% RH), HR

is 43,400 Btuh. TC is 34,400 Btuh. If the kW(2.73) is conve rted to Btuh (2.73 x 3.412 =9.31 MBtuh o r 9310 Btuh), and added toTC, the result is HR. Thefore, if HR is within,10-15% of c a ta log p erformanc e, TC shoulda lso b e w ithin spec ifications. There is noneed to c onnec t refrige rant gauges if HR iswithin spec ifications.


11/28




036 Performa nce Data:

3.0 Ton, 1200 CFM, Heating

EWT GPMretaehrepuseDhtiwgnitaeHgnitaeHDPW

PSI FT EAT HC HE LAT KW COP HC HE LAT KW DH COP

30

5.0 1.8 4.2

60 30.2 21.7 83.3 2.47 3.58 26.5 21.7 80.4 2.45 3.8 3.62

70 29.4 20.4 92.7 2.61 3.30 25.5 20.5 89.7 2.56 3.9 3.36

80 28.4 19.2 101.9 2.73 3.05 24.4 19.3 98.9 2.68 4.0 3.11

7.0 3.4 7.8

60 31.1 22.6 84.0 2.50 3.65 27.3 22.7 81.0 2.45 3.9 3.73

70 30.3 21.3 93.4 2.63 3.37 26.3 21.4 90.3 2.58 4.0 3.44

80 29.4 20.0 102.7 2.77 3.12 25.3 20.1 99.5 2.7 4.1 3.19

9.0 5.4 12.5

60 31.5 23.0 84.3 2.50 3.70 27.6 23.2 81.3 2.44 3.9 3.78

70 30.7 21.8 93.7 2.63 3.42 26.6 18.7 90.6 2.58 4.1 3.49

80 29.9 20.4 103.1 2.76 3.17 25.7 20.5 99.8 2.71 4.2 3.23

50

5.0 1.7 3.9

60 39.1 30.3 90.2 2.59 4.42 34.2 30.6 86.4 2.51 4.9 4.57

70 37.9 28.5 99.3 2.73 4.07 32.9 28.8 95.4 2.65 5.0 4.20

80 36.6 26.8 108.3 2.86 3.75 31.5 27.1 104.3 2.78 5.1 3.86

7.0 3.1 7.2

60 40.7 31.7 91.4 2.64 4.52 35.7 32.1 87.5 2.56 5.1 4.67

70 39.4 30.0 100.4 2.78 4.15 34.2 30.2 96.4 2.69 5.2 4.29

80 38.1 28.1 109.4 2.93 3.82 32.8 28.4 105.3 2.83 5.4 3.95

9.0 5.0 11.6

60 41.6 32.6 92.1 2.65 4.59 36.4 32.8 88.1 2.56 5.2 4.76

70 40.2 30.7 101.1 2.79 4.22 34.9 31.1 96.9 2.70 5.3 4.36

80 38.9 28.9 110 2.94 3.88 33.4 29.2 105.8 2.84 5.5 4.01

Entering

Water

Temp (F)

Flow

Rate

(U.S. GPM)

Water

Press. Drop

(PSI & Ft. of Head)

Entering

Air

Temp (F)

Heating

Capacity

(MBtuh)

Heat of

Extraction

(MBtuh)

Leaving

Air

Temp (F)

Input

Power (kW)

Coefficient

of

Performance

Desuperheater

Capacity

(MBtuh)

Figure 10: Typ ical Performance Data - Heating Mode

036 Performa nce Data:3.0 Ton, 1200 CFM, Cooling

EWT GPM

WPD EAT

DB/WB

retaehrepuseDhtiwgnilooCgnilooC

PSI FT TC SC HR KW EER TC SC HR KW DH EER

70

5.0 1.7 3.9

75/63 36.7 26.8 44.8 2.41 15.2 36.9 26.9 44.9 2.35 4.7 15.7

80/67 39.8 27.9 47.6 2.47 16.1 40.0 28.0 47.7 2.40 4.9 16.7

85/71 43.0 29.0 50.5 2.51 17.2 43.3 29.1 50.6 2.46 5.1 17.6

7.0 3.0 6.9

75/63 37.2 27.1 45.0 2.29 16.2 37.4 27.2 45.1 2.26 4.6 16.6

80/67 40.5 28.2 47.9 2.34 17.3 40.4 28.3 48.0 2.31 4.7 17.6

85/71 43.7 29.3 50.8 2.39 18.3 43.9 29.5 50.9 2.34 4.8 18.7

9.0 4.8 11.1

75/63 37.6 27.1 45.2 2.22 16.9 37.8 27.2 45.4 2.21 4.3 17.1

80/67 40.9 28.2 48.1 2.27 18.0 41.1 28.3 48.3 2.26 4.5 18.2

85/71 44.1 29.3 50.9 2.32 19.0 44.3 29.5 51.2 2.30 4.7 19.3

90

5.0 1.6 3.6

75/63 33.4 25.7 43.1 2.98 11.2 33.7 25.9 43.3 2.89 6.3 11.7

80/67 36.3 26.8 45.9 3.04 11.9 36.6 27.0 46.0 2.95 6.4 12.4

85/71 39.2 27.9 48.7 3.09 12.7 39.5 28.0 48.8 3.01 6.6 13.2

7.0 2.8 6.4

75/63 34.0 26.0 43.4 2.81 12.1 34.3 26.2 43.6 2.75 6.0 12.5

80/67 37.0 27.1 46.1 2.87 12.9 37.3 27.2 46.3 2.80 6.2 13.3

85/71 40.0 28.1 48.8 2.92 13.7 40.4 28.3 49.2 2.87 6.3 14.1

9.0 4.5 10.3

75/63 34.4 26.0 43.4 2.73 12.6 34.7 26.2 43.8 2.70 5.8 12.9

80/67 37.4 27.1 46.2 2.78 13.4 37.8 27.2 46.6 2.75 5.9 13.7

85/71 40.4 28.1 49.0 2.85 14.2 40.8 28.3 49.4 2.80 6.1 14.5

Total Cooling, (MBtuh)

= SC + LC (Latent Cap)

Sensible Cooling

(MBtuh)

Heat of

Rejection

(MBtuh)

Input

Power (kW)

Energy

Efficiency

Ratio

Figure 11: Typ ical Performance Data - Coo ling Mode


12/28



Formulas

The formula is the same for HE and HR.The a mount of hea t being extrac tedor rejec ted can b e c alculated if thetemp erature d ifference betwee n wa terentering a nd leaving the c oa xia l hea texcha nger (TD) is known, and the w aterflow (GPM) is mea sured . The only o ther itemneeded is the typ e o f antifreeze. A fluidfac tor is used to rep resent the spec ific heatof the wa ter/antifreeze solution, as we ll asto convert the units (GPM and F) to Btuh.

HE or HR (Btuh) = GPM x TD x Fluid Fac tor

Where: GPM = Flow ra te in U.S. ga llons per

minute TD = Tem p. diff. (between water in& out) Fluid Fac tor = 500 for wa ter; 485 formost antifreezes

Pressure Gauge

(P/N TSPG-GC or equivalent)

Gauge Adapter

(P/N TSPTN) Adapter

Protector

Pocket Thermometer

P/N TSDT or equivalent

Figure 12a: Pressure Gauge with Ada pter

Figures 12a and 12b show the toolsreq uired for c hecking HE and HR. Alltec hnicians installing and servicinggeotherma l heat pump s should have a tleast one set o f these tools.

Flow ra te c an be de termined by mea suringthe p ressure d rop ac ross the coa xia l heatexcha nger. The p ressure g auge and ad apte rshould b e inserted into the P/ T (p ressure/

tempe rature) po rt of the Wate r INc onnec tion. Rec ord the rea d ing. Next, insertthe g auge into the Wate r OUT port, andrec ord the rea d ing. The d ifferenc e b etweenthe IN and OUT is the p ressure d rop .

Onc e the pressure d rop of the hea t

exchange r is known, the flow rate c an bedetermined by consulting the performa ncedata for the p a rticular unit.

Figure 12b: Poc ket Thermometer


13/28




Example:

In heating mo de, mod el 036 has EWT of50F, wa ter pressure IN of 40 psi, and waterp ressure OUT of 35 psi. The pressure d rop ,therefore is 5 psi. Figure 10 shows threewa ter pressure d rop va lues and three w aterflow rates. At 50F, if the pressure drop is 1.7psi, the flow ra te w ould b e 5.0 GPM; if thep ressure drop is 3.1 psi, the flow rate wouldbe 7.0 GPM; and if the pressure drop is 5.0psi, the flow ra te wo uld be 9.0 GPM. The flowrate in this example is 9.0 GPM. Rarely arethe tempe rature and pressure drop exac tlyas show n in the ta b les, so there w ill be som einterpo lat ion req uired (fo r example, 52F EWTand 4.7 psi pressure drop).

NOTE: A large gauge face is prefe rred ,since it will be ea sier to rea d p ressures tothe nearest 0.5 psi. ALWAYS use the samega uge in the IN a nd OUT c onnec tions.The use o f two g auges c ould cause fa lserea d ings, since they c ould both b e out o fc a lib ra tion in op posite d irec tions. Neve rforce the gaug e adapter into the P/ T po rt.The ga uge a da pter could break off in theP/ T port, or the fo rce c ould c ause the ring

holding the P/ T po rt blad der to b ec omed islod ge d, p otentially end ing up in apump imp eller.

Once the flow ra te is dete rmined , thepo cket thermom eter can b e used to ob tainTD. Insert the thermom eter into the WaterIN P/ T port. Rec ord the temperature. Insertthe thermome ter into the Water OUTport, and record the temp erature. The

d ifferenc e between the IN a nd OUTis the TD. In hea ting , EWT (ente ring wa tertem perature) will be warmer than LWT(lea ving w ater temp erature); in co oling itwill be just the op posite.

The last item needed is the type o f fluidc irc ulating through the hea t pump. Asmentioned ea rlier, 500 should b e used for

pure wa ter (op en loop / well water system s).Use 485 for most antifreeze solutions (seeFlow Cente r and Loop Ap plication Manualfor details on antifreeze solutions).

Figure 13 inc ludes an examp le wa ter-to-a irheat p ump in heating mo de; figure 14 showsthe same hea t pump in coo ling . Follow ingare two e xam ples ba sed upo n these figures,which a re shown on the next page .

Example 1: Model 036, ground loop systemwith ProC oo l (ethanol) antifreeze solution,heating mo de.

1) Fluid fac tor = 4852) EWT = 30.0F LWT = 23.5F TD = 6.5F

3) Pressure IN = 40 psiPressure OUT = 36.6 psiPressure drop = 3.4 psiFrom pe rformance d ata , GPM = 7.0

4) HE = GPM x TD x Fluid Fac to rHE = 7.0 x 6.5 x 485 = 22,067 Btuh

Ca talog HE = 21,300 Btuh. Therefo re, unit ispe rforming b etter than spec ifications.

Example 2: Model 036, ground loop system

with ProC oo l (ethanol) antifreeze solution,co oling m ode.

1) Fluid fac tor = 4852) EWT = 90.0F LWT = 101.2F TD = 11.2F3) Pressure IN = 40 psi

Pressure OUT = 36.3 psiPressure drop = 3.7 psiFrom pe rformance d ata , GPM = 8.0

4) HR = GPM x TD x Fluid Fac to r

HR = 8.0 x 11.2 x 485 = 43,456 Btuh

Ca talog HR = 43,400 Btuh. Therefo re, unit ispe rforming b etter than spec ifications.

NOTE: HE and HR should be within 10-15% ofca talog va lues.


14/28




To suction line

AirCoil

Suction

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F

For water-to-water units

substitute a second coaxial

heat exchanger for the air coil.

Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax




troubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

23.5

36.6

30.0

40.070.0 93.4

Figure 13: Hea ting Operation Example


To suction line

AirCoil

Suction

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F


substitute a second coaxialheat exchanger for the air coil.

Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax



(always disconnect duringtroubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

101.2

36.3

90.0

40.075.0 55.0

Figure 14: Coo ling Operation Example


15/28



Sec tion 3: Supe rheat/ Subcoo ling

Overview

Superhea t and subcoo ling a re used todetermine if the heat pump has the p rop errefrigerant c harge, as well as for verifyingthat the condenser and evap orato ra re p erforming p rop erly. Superhea tand subc oo ling c an even be used totroub leshoo t refrige rant c ircuit b loc kages ora bad TXV.

Definitions

Saturation Tem perature: Satura tiontem perature, som etimes ca lled boilingpoint, is the temp erature at w hich arefrige rant c hanges sta te. For exam p le,

Tab le 1 shows tha t refrigerant R-410A hasa saturat ion temperature o f 32F a t 100psi. Therefo re, the refrigerant a t 100 psi is aliquid if it is below 32F, and a gas (va por) ifit is above 32F.

Superheat: Superheat is defined as thenumber of degrees ab ove the saturationtem perature of a refrige rant. For examp le,if the te mperature of refrigerant R-410A is40F a t 100 p si, it ha s 8F of sup erheat, sinc e

the satura tion tempera ture is 32F.

Subc oo ling: Subcooling is defined as thenumber of d eg rees be low the saturationtem perature of a refrige rant. For examp le,if the temperature of refrigerant R-410Ais 28F a t 100 psi, it has 4F of sub cooling,since the satura tion temperature is 32F.

Chec king Superhea t and Subc ooling

Superhea t and subc oo ling should only bec hecked after the hea t of extrac tion orhea t o f rejec tion c a lcula tions (see sec tion2) ind ic a te tha t the unit is performingpoorly. Connec ting refrige rant gaugesshould b e d one a s a last resort.

Chec king supe rhea t a nd subc oo ling req uiresa refrige ra tion g aug e set w ith ma nifold and

hoses, p lus a d igita l thermo coup le typ ethermom eter. Hea t p umps produc ed byEnertec h Manufac turing ha ve two schraderports for service c onne c tions, one a t thed isc harge line o f the com pressor, and onea t the suc tion line of the com pressor. Whenthese p ressures a re used in co njunc tion w iththe suc tion line temperature and liquid line

tempera ture, supe rhea t and subc oo ling c anbe c alcula ted . Insula tion should b e removedfrom the suc tion line a nd liquid line, and thec op per should b e free from insula tion glue,so tha t the thermoc ouple ma kes a goodc onnec tion at the c op pe r line.


16/28



Saturation Saturation SaturationPressure Temp (F) Pressure Temp (F) Pressure Temp (F)

PSIG R-410A PSIG R-410A PSIG R-410A

0 -60 125 43 370 111

2 -58 130 45 375 112

4-54

13547

380113

6 -50 140 49 385 1148 -46 145 51 390 11510 -42 150 53 395 11612 -39 155 55 400 11714 -36 160 57 405 118

16 -33 165 59 410 11918 -30 170 60 415 120

20 -28 175 62 420 12122 -26 180 64 425 12224 -24 185 66 430 12226 -20 190 67 435 12328 -18 195 69 440 124

30 -16 200 70 445 12532 -14 205 72 450 126

34 -12 210 73 455 12736 -10 215 75 460 12838 -8 220 76 465 12940 -6 225 78 470 13042 -4 230 79 475 13044 -3 235 80 480 13146 -2 240 82 485 132

48 0 245 83 490 13350 1 250 84 495 13452 3 255 85 500 13454 4 260 87 505 135

56 6 265 88 510 13658 7 270 89 515 13760 8 275 90 520 138

62 10 280 91 525 13864 11 285 92 530 13966 13 290 94 535 14068 14 295 95 540 14170 15 300 96 545 14272 16 305 97 550 14274 17 310 98 555 143

76 19 315 99 560 14478 20 320 100 565 14580 21 325 101 570 14685 24 330 102 575 14690 26 335 104 580 14795 29 340 105 585 148

100 32 345 106 590 149

105 34 350 108 595 149110 36 355 108 600 149115 39 360 109 650 154120 41 365 110 700 159

Table 1: Pressure/ Temperature Chart, R-410A Refrigerant


17/28




Saturation Saturation SaturationPressure Temp (F) Pressure Temp (F) Pressure Temp (F)

PSIG R-22 PSIG R-22 PSIG R-22

0 -41 90 54 300 132

2 -37 95 56 305 133

4-32

10059

310134

6 -28 105 62 315 1358 -24 110 64 320 13610 -20 115 67 325 13712 -17 120 69 330 13814 -14 125 72 335 140

16 -11 130 74 340 14118 -8 135 76 345 142

20 -5 140 78 350 14422 -3 145 81 355 14424 0 150 83 360 14526 2 155 85 365 14628 5 160 87 370 147

30 7 165 89 375 14832 9 170 91 380 149

34 11 175 93 385 15136 13 180 94 390 15238 15 185 96 395 15340 17 190 98 400 15542 19 195 100 405 15544 21 200 101 410 15646 23 205 103 415 158

48 24 210 105 420 15950 26 215 107 425 16052 28 220 108 430 16054 29 225 110 435 161

56 31 230 112 440 16258 32 235 113 445 16360 34 240 115 450 164

62 35 245 116 455 16564 37 250 118 460 16766 38 255 119 465 16868 40 260 120 470 16970 41 265 121 475 16972 42 270 123 480 17074 44 275 124 485 171

76 45 280 126 490 17278 46 285 127 495 17380 48 290 129 500 17385 51 295 130

Table 2: Pressure/ Tem pera ture Chart, R-22 Refrigerant


18/28



F


To suction line


F


F

Discharge Line

psi

(saturation)

Suction Line

psi

(saturation)

F

Suction temp

F

For water-to-water unitssubstitute a second coaxial


Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax

Optional desuperheaterinstalled in discharge line(always disconnect during

troubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

R-410A Manifold/Gauge Set

Suction Discharge

F

Thermometer

1

2

21


To suction line


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F



Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax


troubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

R-410A Manifold/Gauge Set

Suction Discharge

F

Thermometer

1

2

21

Figure 15a: Superhea t/ Subc oo ling Measurement - Hea ting

Figure 15b: Superhea t/ Subc oo ling Measurement - Cooling


19/28




Figures 15a and 15b illustrate the locationsfor taking p ressure and tem peraturemeasurements. Notice that the two a rea sfor tem perature mea surement a re suc tionline a nd liquid line. In orde r to c hec ksuperhea t and subcoo ling, the satura tiontempe ra ture must be de termined , whichreq uires the pressure of the refrigerant a ndthe a c tual temp erature of the refrige ranta t the same loc ation. How ever, the onlyloc ation where b oth tempe rature a ndpressure a re ea sily ob ta ined is a t thesuc tion line. In sec tion 1, temperaturesand pressures were d iscussed in rela tionto c omp onents, bo th before a nd a fterthe c omponents. It was a lso mentionedtha t the d ischarge pressure a nd the

liquid line p ressure are within a few psiof ea c h other. Most ma nufac turers ofpac kaged eq uipment ad just their servic edata to a llow the tec hnic ian to use thedischarge pressure as the liquid linepressure. Therefo re, for c hec king superhea tand subcoo ling , use d isc harge pressurewith liquid line temp erature, and suc tionpressure with suc tion temperature.

Although supe rhea t and subc oo ling c an

be c alculated anywhere in the refrige rationc ircuit, there a re tw o p oints tha t a re mostuseful for troub leshooting purpo ses. First ofa ll, it is imperat ive tha t liquid is not returnedto the com pressor. Liquid refrigerantwill wa sh some o f the c ompressor oilawa y from c ritic a l internal parts, causingpremature compressor failure. Plus, thec om pressor is designed to pump gas, notliquid , and will be operating und er adverse

c ond itions. Chec king fo r superhea t a t thesuc tion line of the compressor insures tha tthe sta te of the refrigerant a t this point isa gas (vap or). The a mount of superhea ta t the suc tion line d ete rmines how wellthe evaporato r (coa x in hea ting , a ir coil inc oo ling) is working . Superheat is norma llyin the 8 to 12F rang e, but the insta lla tionma nual will p rovide spec ific informa tion for

the unit be ing servic ed . NOTE: Check thetem perature of the suc tion line near theTXV bulb , espec ially on sp lit systems.

The othe r loc ation to chec k is the liquidline. Since the liquid line is loc a ted a fterthe c ond enser (air coil in hea ting , coa xin hea ting), the a mount of subc oo lingdete rmines how well the c ond enser isworking. In most cases subcooling is in the4 to 10F range, but the insta lla tion manua lwill provide spec ific informa tion for the unitbeing serviced .

Putting It All Tog ethe r

In sec tion 1, TXV operation was d iscussed.

Since the TXV spring has been ad justedto ma inta in 8 to 12F of superhea t, it w illc lose dow n when nec essary to ma inta inthe predetermined superheat setting.Therefo re, subcoo ling p lays a c ruc ia l part ineva luating the unit s refrigeration c harge . Inother wo rds, if the unit is overcharged , theTXV will c lose d ow n to m aintain superheat,backing up liquid refrige rant in thecondenser. If only superheat is mea sured,the tec hnic ian would not know tha t the unit

is ove rcharged . If subcoo ling is mea sured ,the high va lue would indica te tha t thereis a p rob lem with the refrigeration c harge.Tab le 3 lists the c ond itions assoc iated withhigh o r low superhea t and subc oo ling.Tab le 4 is an example o f typica l data foundin the insta lla tion manual.

Figures 16 through 18 illustrate examplesof a norma lly cha rge d system , an

undercharged system, and anoverc harge d system .


20/28


Superheat Subcooling Condition

Normal Normal Normal operation

Normal High Overcharged

High Low Undercharged

High High Restriction or TXV is stuck almost closedLow Low TXV is stuck open

Heating - Without Desuperheater

EWT GPM

Per Ton

Discharge

Pressure

(PSIG)

Suction

Pressure

(PSIG)

Sub

Cooling

Super

Heat

Air

Temperature

Rise (F-DB)

Water

Temperature

Drop (F)

301.5

3

285-310

290-315

68-76

70-80

4-10

4-10

8-12

8-12

14-20

16-22

5-8

3-6

501.5

3

315-345

320-350

100-110

105-115

6-12

6-12

9-14

9-14

22-28

24-30

7-10

5-8

701.5

3

355-395

360-390

135-145

140-150

7-12

7-12

10-15

10-15

30-36

32-38

9-12

7-10

Cooling - Without Desuperheater

EWT GPM

Per Ton

Discharge

Pressure

(PSIG)

Suction

Pressure

(PSIG)

Sub

Cooling

Super

Heat

Air

Temperature

Drop (F-DB)

Water

Temperature

Rise (F)

501.5

3

220-235

190-210

120-130

120-130

10-16

10-16

12-20

12-20

20-26

20-26

19-23

9-12

701.5

3

280-300

250-270

125-135

125-135

8-14

8-14

10-16

10-16

19-24

19-24

18-22

9-12

Tab le 3: Supe rheat/ Subc oo ling Conditions

Table 4: Typ ical R-410A Unit Superheat/ Subcoo ling Values



21/28




Figure 16: Norma lly-Charged System, Hea ting Mode

Figure 17: Unde r-Charged System, Hea ting Mode


To suction line

AirCoil

Suction

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F



LoadCoax

AirCoil

TXV

Filter Drier

Reversing

Valve

SourceCoax



troubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

30.0

40.0

7.0

23.5

36.6

76 19

300

29

90.0

70.0

Superheat =

29 - 19 = 10F

Subcooling =

96 - 90 = 6F


To suction line

AirCoil

Suction

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F



Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax



troubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

30.0

40.0

7.0

26.5

36.6

68 14

260 87

29

87.0

70.0 90.0

Superheat =

29 - 14 = 15F

Subcooling =

87 - 87 = 0F


22/28



Figure 18: Over-Charged System , Hea ting Mode


To suction line

AirCoil

Suction

Coax

Discharge

HeatingMode

AirCoil

Suction

Coax

Discharge

CoolingMode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F




LoadCoax

AirCoil

TXV

Filter Drier

Reversing

Valve

SourceCoax



(always disconnect duringtroubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

30.0

40.0

26.5

36.6

85 24

325 101

34

85.0

70.0 90.0

Superheat =

34 - 24 = 10F

Subcooling =

101 - 85=16F


23/28



Sec tion 4: Desuperhea ter Operation

The d esuperhea ter op tion inc ludes a wa ter-to-refrige rant c oa xial hea t excha ngerinsta lled betw een the c om pressord ischarge line and reversing va lve, whichis connec ted to the c ond enser (air c oil inhea ting, co ax in coo ling) as show n in figure19. Unlike the source coa x in a ll EnertechManufac turing geo therma l heat pump s,the d esuperhea ter coax is a do uble-wall, vented water-to-refrigeration heatexchanger. Figure 20 illustrates a cut-awayof the de superhea ter coa x.

The op eration of the desuperhea tertakes adva ntag e of the supe rhea t atthe d ischarge line. For exam ple, in figure16, the d ischa rge p ressure is 300 psi. The

saturat ion temperature a t 300 psi is 96F.The d ischarge line a t the se cond itionswould typ ica lly be a round 160F. Therefore,

the supe rhea t (ac tual temp era ture saturation temperature) is 64F. Asdo mestic hot wa ter flow s throug h thedesupe rhea ter heat exchanger, some ofthe superhea t a t the d ischarge line is usedto heat dom estic water, which low ers thesuperhea t a t the d ischarge line, thus theterm desuperheater.

Water flow rate through the desupe rhea tercoa x must be ve ry low to a void turningthe d esuperhea ter into a c ond ensor, and robbing too muc h hea t from the ma incondenser. Typ ica lly, ab out 0.4 GPM p erton is used for desuperhea ter flow ra te . Thedesupe rhea ter pum p operate s anytime thecom pressor is op erat ing (unless the one of

the temperature limits is open).

Figure 19: Water-to-Air Refrige rant Circuit with Desuperheater


To suction line

AirCoil

Suction

Coax

Discharge

HeatingMode

AirCoil

Suction

Coax

Discharge

CoolingMode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F




Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

Coax

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

Desuperheater


24/28


In c oo ling, the desuperhea ter takes som eof the heat that wo uld ha ve been rejec tedto the g round loop via the c ondenser(coa x), and uses it to ma ke dom estichot water. Therefore, the d esuperhea terproduc es nea rly free hot w ate r (otherthan the frac tional horsep ow er c ircula tingpump ) in the coo ling mo de .

In hea ting, the d esuperhea ter takes som eof the hea t that w ould have b een usedto hea t the spa c e via the cond enser (aircoil), and uses it to ma ke domestic ho twa ter. Even thoug h the desuperhea teris rob b ing some o f the hea t from thespace, it is a very sma ll amount, and thesystem is heating wa ter a t a very high

C.O.P. (3.0 to 4.0, dep end ing upon looptemp erature), com pa red to a n electricwa ter hea ter at a C.O.P. of 1.0.

Some g eo thermal hea t pump s turn off thedesuperheater pump when ba ck up hea tis energized. However, studies show that onan a nnua l ba sis, the system is more energyefficient when the desuperheater is utilizedany time the c om pressor is running. Whenthe hot wa ter tank is alrea dy hea ted , a

therma l switc h turns off the desuperhea terpum p. The p ump ma y also b e turned o ff ifthe compressor discharge line is too cool.

Steel Outer Wall

Rifled Copper Tube

Smooth WallInner Tube

Refrigerant

Air Gap

Water

Figure 20: Desuperheater coax cut-a way


25/28



Append ix A: Troubleshooting Forms

Diag ram A: Water-to-Air and Water-to-Water Units

Diag ram B: Split Systems

Customer/ Job Na me:____________________________________________ Da te:________________________________

Model # :__________________________________________ Seria l # :____________________________________________

Antifre eze Typ e:____________________________________HE or HR = GPM x TD x Fluid Fac tor(Use 500 for water; 485 for antifreeze)

SH = Suc tion Temp. - Suc tion Sat.SC = Disch. Sat. - Liq . Line Temp.


To suction line

AirCoil

Suction

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode

Common liquid line

AirCoil

Htg TXV

Filter Drier

ReversingValve

Source

Coax

Optional desuperheaterinstalled in discharge line


troubleshooting)

Condenser (heating)Evaporator (cooling)

Condenser (cooling)Evaporator (heating)

Suction

Discharge

IN


To suction line

Clg TXVIN

Line set

Air Handler Compressor Section

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

F

GPM

Return Air

FSupply Air

F

Note: DO NOT connec trefrigerant ga uges

until Heat of Extractionor Rejec tion has be en

checked.


To suction line

AirCoil

Suction

Coax

Discharge

HeatingMode

AirCoil

Suction

Coax

Discharge

CoolingMode


F


F

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F




Load

Coax

AirCoil

TXV

Filter Drier

ReversingValve

SourceCoax




troubleshooting)

Source (loop) IN

Source (loop) OUT

F

psi

F

psi

Load IN

F

psi

Load OUT

F

psi

Return Air

FSupply Air

F

GPM

GPM

Note: DO NOT connec t

refrigerant ga ugesuntil Heat of Extraction

or Rejec tion has be enchecked.

Note: Disconnect desuperheater before proceeding



26/28


Appendix A: Troubleshoo ting Forms

Diagram C: Com bo Unit -- Forced Air Mod e

Diagram D: Com bo Unit -- Water Hea ting Mode

Customer/ Job Na me:____________________________________________ Da te:________________________________

Model # :__________________________________________ Seria l # :____________________________________________

Antifre eze Typ e:____________________________________HE or HR = GPM x TD x Fluid Fac tor(Use 500 for water; 485 for antifreeze)

SH = Suc tion Temp. - Suc tion Sat.SC = Disch. Sat. - Liq. Line Temp.

To suctionline bulb

Tosuction

line

Liquid line

(heating)

Liquid line (cooling)Load

Coax

AirCoil

TXV

Filter Drier

Reversing

Valve

Source

CoaxOptional desuperheater


troubleshooting)


Not used in cooling

Condenser (cooling)

Evaporator (heating) Suction

Discharge

Condenser (heating)



Direction

Valve

3-Way

Valve

NOTE: Black lines show inactive part

of circuit when in forced air mode.

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F

FF

Return Air

F

Supply Air

FAirC

oil

Suction

Coax

Discharge

Heating

Mode

AirCoil

Suction

Coax

Discharge

Cooling

Mode

Source (loop) OUT

F

psi

Source (loop) IN

F

psi

GPM

To

discharge

line

To

suctionline

Note: DO NOT connec trefrigerant ga uges

until Heat of Extractionor Rejec tion has be en

checked.

Note: Disc onnec tdesuperheater before

proceeding

To suctionline bulb

Tosuction

line

Liquid line (cooling)LoadCoax

AirCoil

TXVFilter Drier

ReversingValve

Source

Coax


troubleshooting)


Not used in cooling

Condenser (cooling)Evaporator (heating) Suction

Discharge

To

discharge

line

Condenser (heating)Evaporator (cooling)


Direction

Valve

3-Way

Valve

NOTE: Black lines show inactive part

of circuit when in hot water mode.

Discharge Line

psi

(saturation)

F

Suction Line

psi

(saturation)

F

Suction temp

F

Liquid line(heating)

F

F

Source (loop) OUT

F

psi

Source (loop) IN

F

psi

GPM

Load IN

F

psi

Load OUT

F

psi

GPM

Tosuction

line

Note: DO NOT connec t

refrigerant ga ugesuntil Heat of Extraction

or Rejec tion has be enchecked.



27/28



NOTES


28/28

Enertec h Ma nufac turing is c ontinua lly wo rking to imp rove its prod uc ts. As a result, the d esign and spe c ific ations of

ea c h produc t ma y cha nge w ithout notice a nd m ay not b e a s de scribe d herein. For the most up-to-date information,plea se visit our web site, or contac t our Custom er Service dep artme nt at info@enertechmfg .co m. Sta tem ents and othe r

information c onta ined herein a re no t express wa rranties and do not form the b asis of a ny ba rga in betwe en the pa rties,

but a re m erely Enertech M anufac turing s op inion o r com me nda tion o f its produc ts

2506 South Elm StreetGreenville, IL 62246

www.enertechmfg.cominfo@enertec hmfg .c om

23230028001 refrig trouble hooting manual

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