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Feb 1, 2000

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Sizing Gen-Sets For Large Motor Starting

Larry A. Bey, Cummins Onan Corp. | Electrical Construction and Maintenance

Remember, an on-site engine-generator set is a limited source of power, both in horsepower available

from the engine, and kVA available from the generator. As such, it must be large enough to start as well as

run connected motor loads. You've lost normal power. Your engine-generator set (gen-set starts up and

reaches speed. !ow, "ou want to start some large motors ke" to "our operation. #uddenl",

Sizing Gen-Sets For Large MotorStarting

Feb 1, 2008 12:00 PM, By Larry A. Bey, Cummins Onan

Corp.

Remember, an on-site engine-generator set is a limited

source of power, both in horsepower available from the

engine, and kVA available from the generator. As such, it

must be large enough to start as well as run connected motor loads.

ou've os! norma po"er. Your en#ine$#enera!or se! %#en$se!& s!ar!s up an rea()es

spee. *o", you "an! !o s!ar! some ar#e mo!ors +ey !o your opera!ion. ueny, s!ar!er

)oin# (ois rop ou!, s!ar!er (on!a(!s ()a!!er, an a -e" mo!ors s!a ue !o insu--i(ien!

!orue -or a((eera!ion. Can !)is )appen !o you/ ! sure (an, i- you )aven'! sie your #en$

se! propery.

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e a +no" !)a! mo!ors ra" a )i#) inrus) (urren! urin# s!ar!in#:!ypi(ay si3 !imes -u

oa (urren!. Bu!, inrus) (urren!s -or !)e )i#)$e--i(ien! mo!ors spe(i-ie !oay are amos!

oube !)a! amoun!. Mo!ors "i!) )i#) iner!ia oas (an aso reuire up !o !)ree !imes

ra!e po"er urin# s!ar!in#.

Yes, i!'s (ommon -or mo!or s!ar!in# +4A reuiremen!s !o e!ermine !)e sie o- !)e se!.

5o"ever, !)e -oo"in# -a(!ors aso pay a +ey roe in siin# #en$se!s:

!+ats in-o(-e*. )en s!ar!in# mo!ors, ar#e vo!a#e an -reuen(y ips may o((ur i-

!)e #enera!or se! isn'! sie propery. O!)er oas (onne(!e !o !)e #enera!or ou!pu! may

be more sensi!ive !o vo!a#e an -reuen(y ips !)an !)e mo!or or mo!or s!ar!er, an !)is

may (ause probems. For e3ampe, a ra!e o- ()an#e #rea!er !)an 1 56se( in #enera!or

-reuen(y may (ause some s!a!i( 7P uni!s !o ma-un(!ion.

- !)e oa on !)e #enera!or se! is a sin#e ar#e mo!or, par!i(uary one reuirin# )i#)

s!ar!in# !orue, a number o- probems (an o((ur. )ey in(ue: sus!aine o"$vo!a#e

opera!ion !)a! (an (ause over)ea!in#9 e3!ene oa a((eera!ion !imes9 openin# o- (ir(ui!

brea+ers or mo!or pro!e(!ive evi(es9 en#ine$#enera!or pro!e(!ion s)u!o"ns9 an more.

Your #en$se!'s abii!y !o s!ar! ar#e mo!ors "i!)ou! e3(essive vo!a#e an -reuen(y ip is

a -un(!ion o- !)e (ompe!e sys!em. )is in(ues:

You mus! (onsier a !)ese -a(!ors -or proper #en$se! siin#. 5ere's a simpe rue -or

es!ima!in# !)e sie o- an en#ine$#enera!or se! -or mo!or s!ar!in#: 1+ o- #enera!or se!

ra!in# per ea() 6; !o 1 )p o- mo!or namepa!e.

Lets (oo more c(ose(y at a motor start. nu(!ion mo!ors )ave !ypi(a s!ar!in#

()ara(!eris!i(s. )e (urve o- mo!or (urren! versus spee s)o"s !)a! urin# s!ar!in#, !)e

mo!or ra"s appro3ima!ey si3 !imes i!s -u oa (urren!9 !)is (urren! remains )i#) un!i

!)e mo!or rea()es abou! 80< o- spee. )is )i#) inrus) (urren! (auses a ip in #enera!or

vo!a#e. )e ee(!ri( po"er ini!iay reuire by !)e mo!or %"i!) !)e mo!or a! s!ans!i& is

abou! 1=0< o- ra!e po"er. )e po"er reuire by !)e mo!or pea+s a! abou! 00< o-

ra!e po"er an 80< o- spee "i!) -u vo!a#e appie. Bu!, !)e #enera!or se! suppies

ess !)an 00< po"er be(ause s!ar!in# vo!a#e is o"er !)an -u vo!a#e urin#

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5armoni(s (ause by variabe -reuen(y rives.>

7se o- )i#)$e--i(ien(y mo!ors.>

euen!ia s!ar!in# o- mo!ors.>

)e en#ine po"er avaiabe9>

)e #enera!or's (apa(i!y9>

)e response o- !)e #enera!or e3(i!a!ion sys!em9>

)e ener#y s!ore in !)e ro!a!in# iner!ia o- !)e #en$se!9 an>

)e a((eera!ion o- !)e mo!or an i!s oa.>

+1& 2eb+1& 2eb+1& 2eb+1& 2eb

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a((eera!ion, an be(ause !)e #enera!or se!'s ro!a!in# iner!ia !rans-ers ener#y !o !)e

mo!or.

)e mo!or mus! eveop #rea!er !orue !)an reuire by !)e oa. )e mo!or's !orue

(urve a! -u vo!a#e is above !)e oa's !orue (urve. )e i--eren(e be!"een !)e !orue

eveope by mo!or an !)e !orue reuire by !)e oa e!ermines !)e ra!e o-

a((eera!ion. in(e !orue is propor!iona !o vo!a#e, any reu(!ion in vo!a#e means a

propor!iona reu(!ion in !orue.

A propery sie #enera!or se! "i suppor! !)e )i#) s!ar!in# +4A reuiremen!s o- !)e

mo!or, an main!ain su--i(ien! ou!pu! vo!a#e -or !)e mo!or, so i! (an eveop aeua!e

!orue !o a((eera!e !)e oa !o ra!e spee.

A s!anby #en$se!s use syn()ronous #enera!ors "i!) e3(i!ers. Many are avaiabe "i!)

permanen! ma#ne! #enera!or %PM?& e3(i!a!ion sys!ems. )e PM? provies e3(i!a!ion

po"er inepenen! o- !)e #enera!or !ermina vo!a#e. As su(), i! (an main!ain -u

e3(i!a!ion:even urin# !ransien! oain#, su() as mo!or s!ar!in#. Fu e3(i!a!ion po"er

resu!s in a ess e3!ensive vo!a#e ip an improve re(overy !imes.

Using re*uce*0-o(tage starting. )ou#) a vo!a#e ip o-!en (auses various probems,

a (on!roe reu(!ion in vo!a#e a! mo!or !erminas (an be bene-i(ia, bu! ony ")en

reu(!ion in mo!or !orue is a((ep!abe. @eu(in# mo!or s!ar!in# +4A (an reu(e !)e

reuire sie o- !)e #en$se!, reu(e !)e vo!a#e ip, an provie a so-!er s!ar! -or !)e

mo!or oas. )en siin# #en$se!s, you mus! -irs! e!ermine !)e a((ep!abe eve o- mo!or

!orue reuire urin# s!ar!in#, or !)e oas "i a((eera!e so"y, or even -ai !o rea()

-u spee:u!ima!ey (ausin# mo!or ama#e.

Using so(i*0state starters. oi$s!a!e s!ar!ers (an aus! !)e s!ar!in# !orue,a((eera!ion ramp !ime, an (urren! imi! -or (on!roe a((eera!ion o- a mo!or ")en i!

s!ar!s. For !)e purpose o- siin# a #en$se!, !)e (urren! imi! aus!men! reu(es !)e inrus)

(urren! an may be use !o reu(e !)e s!ar!in# + an +4A reuiremen! on !)e

#enera!or. )e ran#e o- avaiabe (urren! imi! se!!in#s is !ypi(ay -rom 1=0< !o 00< o-

-u$oa (urren!. A 00< (urren! imi! se!!in# on !)e soi$s!a!e s!ar!er resu!s in a #en$

se! siin# !)a!'s !)e same as an a(ross$!)e$ine s!ar!in#. A 00< (urren! imi! se!!in#

reu(es s!ar!in# +4A by =0<.

7se o- !)e (urren! imi! se!!in# aso reu(es mo!or !orue avaiabe !o !)e oa. From a

#en$se! siin# perspe(!ive, an e3!ene a((eera!ion ramp !ime an o" (urren! imi!

se!!in# %i- appropria!e -or !)e mo!or an !)e me()ani(a oa& "ou resu! in !)e eas!

vo!a#e an -reuen(y e3(ursions.

One o"nsie !o usin# soi$s!a!e mo!or s!ar!ers is !)eir in!e#ra C@s %sii(on$(on!roe

re(!i-iers& "i (ause vo!a#e is!or!ion. o (ompensa!e, you' )ave !o oversie !)e

#enera!or. )e re(ommena!ion: !"o !imes !)e runnin# + oa, e3(ep! ")ere you're

usin# an au!oma!i( bypass. - !)e soi$s!a!e s!ar!er oes )ave an au!oma!i( bypass, !)e

C@s are ony in !)e (ir(ui! urin# s!ar!in#. On(e !)e mo!or is runnin#, !)e bypass

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(on!a(!or (oses an s)un!s !)e C@s. n !)is (ase, you (an i#nore !)e vo!a#e is!or!ion

urin# s!ar!in#, an you on'! )ave !o a #enera!or (apa(i!y.

/F#s re3uire (arger generators. A versions o- variabe -reuen(y rives %4Fs& are

(urren! imi!in# an reu(e s!ar!in# + an +4A. )e (urren! ra"n by !)ese rives is

noninear %)avin# )armoni(s&, ")i() (auses a is!or!e vo!a#e rop a(ross !)e rea(!an(e

o- !)e #enera!or. in(e 4Fs are noninear, you mus! in(ue an ai!iona #enera!or

(apa(i!y siin# -a(!or !o +eep vo!a#e is!or!ion !o a reasonabe eve o- appro3ima!ey 1=<!o!a )armoni( is!or!ion %5& or ess. )e ar#er !)e #enera!or, !)e #rea!er !)e

reu(!ion in impean(e o- !)e po"er sour(e %#enera!or&, ")i() in !urn, reu(es !)e

e--e(!s (ause by )armoni( (urren! is!or!ion.

For si3$puse 4Fs, a !ypi(a #enera!or siin# -a(!or "ou be !"i(e !)e runnin# + o- !)e

rive. )is o--se!s any reu(!ion in s!ar!in# + an +4A. - i! is !)e puse "i!)

moua!e %PM& !ype %or in(ues an inpu! -i!er !o imi! (urren! is!or!ion !o ess !)an

10<&, !)en you (an reu(e !)e siin# -a(!or o"n !o 1.; !imes !)e runnin# + o- !)e rive.

Using a step starting se3uence. )e s!ar!in# seuen(e o- oas (an )ave a si#ni-i(an!e--e(! on !)e sie o- a #en$se!. One (ommony use approa() is !o assume a (onne(!e

oas "i s!ar! in a sin#e s!ep. )is resu!s in !)e ar#es! #en$se! see(!ion. 7ness you o

some!)in# !o a oa in(remen!ay %su() as mu!ipe !rans-er s"i!()es "i!) s!a##ere

!ime eays, or a s!ep oa (on!roer&, !)en you s)ou use a sin#e$s!ep oa -or siin#

purposes.

n mu!ipe s!ep appi(a!ions, you s!ar! !)e ar#es! mo!or -irs!, !o minimie !)e #en$se!

sie. On(e pa(in# a oas on ine "i!) !)e #en$se!, you (an s!op an s!ar! oa

euipmen! "i!) au!oma!i( (on!ros. 5ere, you' )ave !o sie !)e #en$se! by assumin# !)e

ar#es! mo!or s!ar!s as!, "i!) a o!)er (onne(!e oas areay on ine.

E4amp(es o$ sizing gen0sets. You (an sie a #en$se! "i!) manua (a(ua!ions %usin# a

"or+s)ee!& or "i!) PC so-!"are avaiabe -rom mos! maor #en$se! manu-a(!urers. )e

basi( pro(ess is !)e same. !'s a"ays bes! !o use a(!ua a!a %i- +no"n&.

- !)is in-orma!ion isn'! avaiabe, usin# PC so-!"are is !)e bes! op!ion, sin(e mu() o- !)e

reuire in-orma!ion on !ypi(a oa ()ara(!eris!i(s is avaiabe as e-au! in-orma!ion. -

you use !)e manua siin# pro(eure, i! s)ou resu! in a re(overy vo!a#e o- a! eas! D0<

o- ra!e vo!a#e an a s!ar!in# ins!an!aneous vo!a#e ip o- appro3ima!ey 20< !o ;0<.

)e ins!an!aneous vo!a#e ip an -reuen(y ip "i i+ey vary -rom manu-a(!urer !o

manu-a(!urer, base on eua ra!in#s o- #en$se!s. For a (oser es!ima!ion o- !ransien!

%s!ar!in# ins!an!aneous vo!a#e& per-orman(e, use !)e manu-a(!urer's siin# so-!"are.

Using t+e manua( sizing proce*ure.

Step 1: ?a!)er in-orma!ion. You' nee !o +no" !)e -oo"in# -or ea() mo!or oa:

*amepa!e )p,>



You (an use !)e -oo"in# eua!ion !o (a(ua!e @+ an @+4A -or mo!ors: @+ E

%*amepa!e )p& 3 %0.G;+6)p&H 6 I--i(ien(y %e. 1&

@+4A E @+ 6 @unnin# mo!or PF %e. 2&

o (a(ua!e s!ar!in# +iovo!$amperes %+4A& an s!ar!in# +io"a!!s %+& -or mo!ors,

use !)ese eua!ions:

+4A E %*amepa!e )p& 3 %Lo(+e ro!or +4A6)p& %e. &

+ E %+4A& 3 %!ar!in# mo!or PF& %e. ;&

!ep 2: o!a !)e @+, @+4A, +, an +4A numbers -or a !)e oas.

!ep : ee(! !)e #en$se! by (omparin# !)e @+, @+4A, +, an +4A !o !)e ra!in#s on

!)e manu-a(!urer's spe(i-i(a!ion s)ee!s %a-!er appropria!e era!in# -or ambien!

!empera!ure an a!i!ue&.

E4amp(e One ca(cu(ation. e!ermine #en$se! sie -or !)ree oas s!ar!e a(ross$!)e$

ine in a sin#e s!ep. 5ere's per!inen! in-orma!ion:

Step 1: n-orma!ion #a!)erin# an (a(ua!ions. 200 5P mo!or:

@+ E %200 )p 3 0.G; +6)p& 6 0.D2 E 12.2+

@+4A E 12.2+ 6 0.D1 PF E 1G8.2+4A

+4A E 200 )p 3 =.D +4A6)p;1180+4A

+ E 1180+4A 3 0.2= PF E 2D=+

Fores(en! Li#)!in#:

@+ E 100+4A 3 0.D= PF E D=+

@+4A E 100+4A

@unnin# +io"a!!s %@+&,>

@unnin# +iovo!$amperes %@+4A&,>

@unnin# mo!or po"er -a(!or %PF&,>

!ar!in# mo!or PF, an>

Lo(+e ro!or +4A6)p.>

"o 200 )p mo!ors, Coe ?, D2< runnin# e--i(ien(y, 0.2= s!ar!in# PF, 0.D1 runnin# PF.>

o!a 100+4A o- -uores(en! i#)!in#, s!ar!in# PF o- 0.D=, an runnin# PF o- 0.D= %*o!e:

e're usin# !)e !erms s!ar!in# an runnin# PF -or !)e i#)!in# oa )ere -or (ari-i(a!ion

")en ain# !)e mo!or oas. A(!uay, !)e baas! -or !)e i#)!in# oa )as a (ons!an! PF

o- 0.D=.&

>



+4A E 100+4A

+ E 100+4A 3 0.D= PF E D=+

Step : o!as.

Loa.......... J @+ J @+4A J + J +4A

200)p Mo!or J 12.2 J 1G8.2 J 2D= J 1180

200)p Mo!or J 12.2 J 1G8.2 J 2D= J 1180

Li#)!in#....... J D=.... J 100... J D=. J 100

o!as %+4A&. J ;20... J ;=G.. J 8= J 2;0

Step !: ee(!ion. A! a minimum, you' )ave !o sie !)e #en$se! !o suppy !)e ma3imum

s!ar!in# %sur#e& emans an !)e s!eay$s!a!e runnin# oas o- !)e (onne(!e oa

euipmen!. n !)is e3ampe %usin# one manu-a(!urer's pubis)e a!a&, you "ou see(! aG=0+ #enera!or se! "i!) 2D;; +4A avaiabe a! D0< re(overy vo!a#e !o suppy !)e !o!a

oa +4A o- 2;0. )e oa !o!as -or @+, @+4A, an + are "e "i!)in !)e ra!in# o-

!)e G=0+ %D8+4A& #en$se! you see(!e. )e runnin# +io"a!! oa o- ;20+ is =< o-

!)e G=0+ #en$se! s!anby ra!in#.

E4amp(e )o ca(cu(ation. Assume you )ave !)e same !)ree oas as in I3ampe One,

bu! no" you're usin# an au!o!rans-ormer !ype reu(e vo!a#e s!ar!er !)a! is se! a! !)e

=< s!ar!in# vo!a#e !o s!ar! !)e !"o mo!ors. )is !ap se!!in# "i reu(e !)e s!ar!in# +4A

by !)e suare o- !)e vo!a#e %0.=&suare, or 0.;2 !imes !)e s!ar!in# +4A.

Step 1: Ca(ua!ions

200 5P mo!or:

@+ E %200 )p 3 0.G; +6)p& 6 0.D2 E 12.2+

@+4A E 12.2+ 6 0.D1 PF E 1G8.2+4A

+4A E 200 )p 3 =.D +4A6)p E 1180 3 %0.=&suare E ;D=+4A

+ E ;D=+4A 3 0.2= PF E 12;+

Fores(en! Li#)!in#:

@+ E 100+4A 3 0.D= PF E D=+

@+4A E 100+4A

+4A E 100+4A

+ E 100+4A 3 0.D= PF E D=+



!ep 2: o!as

Loa.......... J @+.. J @+4A J + J +4A

200)p Mo!or J 12.2 J 1G8.2. J 12;. J ;D=

200)p Mo!or J 12.2 J 1G8.2. J 12;. J ;D=

Li#)!in#...... J D=..... J 100... J D=... J 100

o!as %+4A& J ;20... J ;=G... J ;. J 10D0

Step !: ee(!ion. 7sin# one manu-a(!urer's pubis)e a!a, you "ou see(! a ;=0+

#en$se! !o suppy !)e reuire s!ar!in# +4A. )e runnin# +io"a!! oa o- ;20+ is D<

o- !)e #en$se!'s s!anby ra!in#. o, i- you "an! a mar#in -or -u!ure oa ai!ions, you

"ou see(! a =00+ #en$se! runnin# a! 8;< o- ra!e s!anby po"er.

Si*ebar1 5eres !+at Causes #ip in Starting /o(tage

)en you s!ar! a mo!or a(ross$!)e$ine "i!) a #en$se!, !)e mo!or represen!s a o"

impean(e oa ")ie a! o(+e ro!or or s!ae (oni!ion. )is (auses a )i#) inrus)

(urren!. )e )i#) mo!or inrus) (urren! % ms& -o"s !)rou#) !)e #enera!or arma!ure

"inin#s an is a--e(!e by !)e rea(!an(e. )is (auses a rop in #enera!or vo!a#e.

mpean(e (on!ros !)e -o" o- (urren! in AC (ir(ui!s. Bu!, !)e #enera!or arma!ure

rea(!an(e is su() a ar#e par! o- i!s !o!a impean(e !)a! resis!an(e is i#nore.

)e #enera!or !ermina vo!a#e rops ins!an!aneousy ")en !)e mo!or s!ar!er (on!a(!s

(ose a! !ime !;0, as a -un(!ion o- !)e sub!ransien! rea(!an(e %K&. ?eneray, !)e ar#er

!)e #enera!or, !)e o"er i!s rea(!an(e. o, one "ay !o minimie !)e ins!an!aneous vo!a#e

ip is !o in(rease !)e #enera!or sie.

)e #enera!or !ermina vo!a#e may rop -ur!)er, epenin# on response o- !)e

#enera!or's au!oma!i( vo!a#e re#ua!or an !)e po"er (apabii!y o- !)e e3(i!a!ion sys!em.

%Mos! #en$se! au!oma!i( vo!a#e re#ua!ors in(ue uner-reuen(y pro!e(!ion.&

urin# momen!ary overoas, !)e en#ine spee may aso ip. - i! oes, !)e au!oma!i(

vo!a#e re#ua!or reu(es e3(i!a!ion po"er !o !)e main -ie, ")i() o"ers !)e #enera!or

!ermina vo!a#e. )is, in !urn, reu(es !)e oa on !)e en#ine, ao"in# i! !o re(over !o

ra!e spee. ypi(ay, a ma3imum #enera!or !ermina vo!a#e ip o- 0< "i no! (ause

(ois !o rop ou!. %)is ao"s -or appro3ima!ey =< ai!iona vo!a#e rop in !)e

(onu(!ors be!"een !)e #enera!or an !)e mo!or&.

A!)ou#) !)e vo!a#e ip, ue !o uner -reuen(y pro!e(!ion, may e3!en !)e vo!a#e

re(overy !ime, i! aso ao"s !)e en#ine !o be sie (oser !o !)e s!eay$s!a!e runnin# oa



ra!)er !)an s!ar!in# oa. )is is par!i(uary impor!an! "i!) iese en#ines, ")i() s)ou

no! run -or an e3!ene ura!ion a! ess !)an 0< o- ra!e oa. %I3!ene i#)!$oa

opera!ion o- a iese en#ine (an resu! in !)e a((umua!ion o- unburne -ue in !)e

e3)aus! sys!em, ue !o in(ompe!e (ombus!ion -rom o" (ombus!ion !empera!ures, (ae

"e! s!a(+in#. Li#)! oa opera!ion (an aso resu! in en#ine ama#e -rom -ue an "a!er

(on!amina!in# ubri(a!in# oi.&

A-!er !)e ini!ia vo!a#e ip, i!'s impor!an! !)e #enera!or res!ore vo!a#e !o a minimum o-D0<$ra!e vaue ")ie suppyin# !)e mo!or s!ar!in# +4A. A! eas! D0< re(overy vo!a#e is

ne(essary -or !)e mo!or !o eveop aeua!e !orue !o a((eera!e i!s oa !o ra!e spee.

A mo!or s!ar!in# a )i#) s!ar!in# !orue oa, su() as a oae (ompressor, reuires )i#)er

re(overy vo!a#e !)an one s!ar!in# an unoae (ompressor. As !)e mo!or (omes up !o

spee, !)e vo!a#e "i rise, as !)e s!ar!in# +4A inpu! e(reases. On(e !)e mo!or is up !o

spee, !)e vo!a#e s)ou re!urn !o ra!e vaue, i- !)e #en$se! is sie propery.

Si*ebar1 5o Inertia A$$ects 6en0Set Sizing

)e momen! o- iner!ia o- a ro!a!in# mass o--ers resis!an(e !o a((eera!ion. )e oa

(onne(!e !o !)e mo!or s)a-! )as i!s momen! o- iner!ia, an in pra(!i(a si!ua!ions -or

spe(i-i( euipmen!, !)is may or may no! be avaiabe in-orma!ion.

For!una!ey, -or !)e purpose o- siin# a #en$se!, or more spe(i-i(ay !o e!ermine !)e

en#ine po"er neee !o s!ar! an a((eera!e a ro!a!in# mo!or oa, !)e mo!or oa's

momen! o- iner!ia nee ony be broay (a!e#orie as o" or )i#) iner!ia.

5i#) iner!ia oas are ()ara(!erie by )i#) brea+a"ay !orue reuirin# proon#e

a((eera!ion. Lo" iner!ia oas are ()ara(!erie by o" s!ar!in# !orue a! s!ans!i, "i!)

in(reasin# !orue as mo!or spee in(reases resu!in# in rapi a((eera!ion !o ra!e spee.

!ar!in# o" iner!ia oas "i reu(e !)e norma s!ar!in# + neee. Loo+ -or more

in-orma!ion on !)is is in !)e sampe (a(ua!ions "i!)in !)is ar!i(e.

Si*ebar1 E4amp(es o$ 5ig+ an* Lo Inertia

5i#) iner!ia oas in(ue:

in#e$ an mu!i$(yiner pumps>

in#e $an mu!i$(yiner (ompressors "i!)ou! unoain# vaves>

Crus)ers>



TWEET

Lo" iner!ia oas in(ue:

*o!e: Pumps s!ar!in# in!o )i#) )ea pressure an ar#e iame!er -ans or -ans s!ar!in#

in!o )i#) res!ri(!ion areas s)ou be (assi-ie as )i#) iner!ia oas.

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5yraui( eeva!ors "i!)ou! unoain# vaves>

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Compressors s!ar!in# unoae>

Cen!ri-u#a pumps>

Mo!or$#enera!or eeva!ors>

6Recommend

Lee C+ee Seng (not verified) on u ;, 2012

Log In or egister to post comments

ear irs, appre(ia!e i- someone (ou eni#)!en me by proviin# a re(ommena!ion o- a

sui!abe #ense! sie -or an e3er(ise as -oo"s:$ )a! "ou be !)e ri#)! sie o- #ense! -or

s!ar!in# a 220N "a!er pump mo!or by au!o$!rans me!)o "i!) a vo!a#e ip imi!a!ion o- no!

more !)an 1=<. )an+ you -or assis!in#. Bes! re#ars 6 Lee C)ee en#

Anonymous (not verified) on u 1D, 2012


very )ep-u Many iese ?enera!or aes peope are ban+ abou! !)e s!ar! up po"er o- mo!ors.

An am ba!!in# !o see(! !)e (orre(! sie o- #enera!or.

Anonymous (not verified) on *ov 2, 201


i i! "i!) an oo"ar easy#en$=00 (on!roer usin# !)e ramp up -ea!ure



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