Universal Enclosures Thermal Solutions Fundamentals: Introduction:heat transfer Universal Enclosures Thermal Solutions Schneider Electric3- Universal Enclosures Training Course Thermal Management 26.02.2009 Plan 1 Object 2 The thermal transfer 3 UE thermal modelling principles- indoor - outdoor 4 UE thermal modelling tools 5 Thermal studies steps applied to important projects 6 Conclusion Schneider Electric4- Universal Enclosures Training Course Thermal Management 26.02.2009 1 Object Offer to the customer the best technical solution according to his constraints without any oversizing

Request : - Physical protection - Thermal protection Constraints : - Place : dimensions - Material - Pint, Tint-max, Tint-min, i Optimal solution Calculation+= Schneider Electric5- Universal Enclosures Training Course Thermal Management 26.02.2009 What is the thermal transfer: Transmission of energy from a region to another because of a difference of temperature 2 concepts: Heat Q unit:joules J Difference of temperature T unit: Celsius (C)or Kelvin (K) or.. 2 important concept: Thermal power The heat exchanges depend of duration Temperature Microscopic particles agitation Unit Celsius Czero =ice fusion temperature Or in Kelvin K zero = the absolute zero 2 The thermal transfer C = K 273,15 Thermal power Heat Seconds Joules Time Watt =>= Schneider Electric6- Universal Enclosures Training Course Thermal Management 26.02.2009 Radiation 2 The thermal transfer 3 thermal transfer modesConductionConvection Material :Inside fluidBetween solid and fluid Between fluid and fluid Material: In the vacuumIn semi-transparent materialMaterialInside solid Inside fluid Schneider Electric7- Universal Enclosures Training Course Thermal Management 26.02.2009 3 ways of heat exchange Internal/external heat exchange of the enclosure 10C 40C Conduction Convection Radiation Enclosure wall Area inside the enclosure Area outside the enclosure Schneider Electric8- Universal Enclosures Training Course Thermal Management 26.02.2009 What is conduction: Energy (or heat) is diffuses in the opaque solid material by direct contact. The energy diffuses inside a material depends of his conductivity Example: A plate length 1m (block.2) in perfectcontact with a block heater (block 1)whose power is 50W. How does theheat diffused if: 1 The block.2 is in steel 2 The block.2 is in polyester 2.a Conduction50 W0 W Steel Polyester Block 2Block 1 54,8C 123C Schneider Electric9- Universal Enclosures Training Course Thermal Management 26.02.2009 What is the convection (Air convection): The heat is transferred inside the air or between the surface of a solid and the air ConvectionAir displacement Heat transfer Two types of displacement by convection: Displacement by natural convection: Displacement by forced convection: - Forced convection is caused by an artificial circulation of the air fan- The forced convection transfer is better than natural one - A fan is characterised by his debit m3/h (quantity of air that the fan can move) Elle sexprime : W 2.b Convection Tp Text Moving fluid The heat transfer between the wall and air depend of: - The wall temperature- The surface - The air temperature - The wall material Schneider Electric10- Universal Enclosures Training Course Thermal Management 26.02.2009 What is radiation Heat transfer is an electromagnetic radiation (EM) It doesnt need any material support propagates in vacuum Any hot solid emits radiations EM What is characterised Loss of energy for the solid who emit Gain of energy for the solid who receive Governed by: 2.c Radiation Tp Text The transfer depend of: - Emission factor of the surface - Surface- Temperature of surface - External temperature Schneider Electric11- Universal Enclosures Training Course Thermal Management 26.02.2009 C = + P

Heat transferred inside WP Heat created inside W CHeat required to change temperatureWinside the volume (calorimetry equation) 2.a Indoor enclosures principles Energy balance P Natural convection: Forced convection: Natural = k.S.(T-Text) Forced = Hot- Cold -Hot: heater -Cold: air conditioner, exchanger, fan.. =Natural+Forced K_steel5,5 W/m.K K_stainless3,7 W/m.K K_Aluminium 12 W/m.K K_Polyester 3,5 W/m.K-T : internal temperature (average) -Text: external temperature - S : exchanging surface Schneider Electric12- Universal Enclosures Training Course Thermal Management 26.02.2009 We suppose that: The internal power is homogeneous sum of infinitesimal power density Steady state No time dependence (C=0) The surface exchange coefficient is constant and depends only of the material The external temperature is constant 3.a Indoor enclosure energy balance Energy balance T P+ S.k Hot - Cold +=Text We can calculate: -Average internal temperature -Cooling capacity needed for an internal temperature -Heating power to ensure an internal temperature - T: internal temperature (average) - Text: external temperature - P: power losses inside- S: exchanging surface - k: exchanging coefficient - Steel: k = 5,5 W/mk - Polyester: k = 3,5 W/mk Schneider Electric13- Universal Enclosures Training Course Thermal Management 26.02.2009 Power < > FLOW RATE The air flow rate equivalent to a power is given by the following formula: 3.a Indoor enclosure fansFlow Rate calculation TPowerDebitA = 3Unit: m3 / h - This formula provides the airflow required for cooling not fan airflow. - The fan airflow should be slightly higher than this rate because of losses caused by the equipment pressure drop. T: temperature difference between outside and inside Power: evacuated from inside to outside The desired internal temperature must be greater than the external temperature of at least 5 C Fan Schneider Electric14- Universal Enclosures Training Course Thermal Management 26.02.2009 3.a Indoor enclosure - sample Answers ? T P+ S.k Hot - Cold +=Text Enclosure such as: - Dimensions 2000x800x800 - Material: Painted Steel - Internal Power: 1500 W - External temperature: 25 C Question 1: What is the average temperature inside the enclosure ? Question 2: What is the power required for 35 C inside ? Question 3: What is the flow rate required for 35 C inside ? TPowerDebitA = 3Schneider Electric15- Universal Enclosures Training Course Thermal Management 26.02.2009 Answer 1 27 ] 8 . 0 8 . 0 [ )] 8 . 0 2 ( 4 [ m S = + =C T = ++ = 645 . 5 70 0 150025Answer 2 )] ( [ext Hot ColdT T S k P u + = uWCold1115 )] 25 35 ( 7 5 . 5 [ 0 1500 = + = uSteel k = 5.5 W/m.k 3.a Indoor enclosure - sample Answer 3 hmTPowerDebit333525 3511153 3 = =A =T P+ S.k Hot - Cold +=Text Enclosure such as: - Dimensions 2000x800x800 - Material: Painted Steel - Internal Power: 1500 W - External temperature: 25 C Question 1: What is the average temperature inside the enclosure ? Question 2: What is the power required for 35 C inside ? Question 3: What is the debit required for 35 C inside ? TPowerDebitA = 3Schneider Electric16- Universal Enclosures Training Course Thermal Management 26.02.2009 3.b Outdoor enclosures Principles Solar radiation to earth = 1353W/mIntercepted by the outer limits of the atmosphere The intensity of radiation depends of : The region Season Time The incident radiation is the sum of three components: direct, diffuse and reflected Schneider Electric17- Universal Enclosures Training Course Thermal Management 26.02.2009 Outside Inside 3.b Outdoor enclosures - Principles What happens when a solar radiation reaches the surface of an opaque solid ? iriaty Rf lectivity Absorptiviuu=uu=o:: The radiative flux absorbed by the wall is An energy increase wall temperature The contribution of radiative energy inside the cabinet is indirect Convection and radiation between the wall and the internal environment The calculation of the wall temperature is fundamental *Invalid argument in the case of glass -iincident flux -a flux absorbed by the wall -rreflected fluxAbsorptivity: - White: 18% - Gray: 75% - Black: 94% Schneider Electric18- Universal Enclosures Training Course Thermal Management 26.02.2009 4 Thermal modelling toolsPrecisionCalculation time minuteshoursdaysweeksmonths ProClima 5 Indoor Permanent T average Models OD (Indoor, Outdoor) ( Transit, Perma) T averageModels 3D Experience Models 1D 3 points (IEC 60890) indoor permanent T (bottom, medium and top) Thermal range Schneider Electric20- Universal Enclosures Training Course Thermal Management 26.02.2009 Thermal management What is Thermal Management? Why is it necessary to control the temperature/humidity? Risks linked to lack of Thermal Management Benefits of suitable Thermal Management The importance of the environment Thermal study Schneider Electric21- Universal Enclosures Training Course Thermal Management 26.02.2009 What is Thermal Management? Thermal Management should guarantee suitable controlof the Temperature and Humidity conditions inside the enclosure to guarantee optimal operation of the components installed in the inside. Schneider Electric22- Universal Enclosures Training Course Thermal Management 26.02.2009 Thermal Indoor Outdoor Installations

CoolingHeatingControl Passive Solutions Airing Ventilation Cooling/Exchanger Heaters Controllers TH,HY,HYT functions Gradient of Solutions Problems Temperature Humidity / Condensation Radiation Software High temp Low temp Quality of external air / ambient Schneider Electric23- Universal Enclosures Training Course Thermal Management 26.02.2009 Installation trendsMost important factors that make thermal management increasingly more necessary Temp. Technological evolution of electrical and electronic equipment Miniaturisationof componentsNew products based on power electronics Trend towards the optimisation of space in enclosures More extreme/severe climatic environments where the most advanced technology is installed. They oblige us to talk about THERMAL PROTECTION in electrical enclosures. Schneider Electric24- Universal Enclosures Training Course Thermal Management 26.02.2009 Why is it necessary to control the temperature/humidity? In enclosures where no thermal management system has been applied: Te Te < T1 < T2 < T3 < T4 The temperature inside the enclosure is always higher than the outside.The inside temperature (Ti) of the enclosure is not even. The top areas will always be hotter than the bottom ones. The walls and roof of the enclosure will always be at an intermediate temperature between the inside temperature and the outside temperature (Te). The roof the enclosure will be at a higher temperature than that of the vertical walls. T2 T3 T4 T1 Schneider Electric25- Universal Enclosures Training Course Thermal Management 26.02.2009 Risks linked to lack of TM Service life of an electrolytic condenser temperature (C)annes de vie 2025 3018 4010.7151931 506 603 701.28528666 800.47863009 900.15 0.1 1 10 100 2030405060708090 temperature (C) year of life. 25 years 20C 4years 55C The service life of the electrical and electronic components depends on the operating temperature (inside temperature of the enclosure). Schneider Electric26- Universal Enclosures Training Course Thermal Management 26.02.2009 Risks linked to lack of TM The most sensitive equipment in the enclosure are those related to electronics. Maximum temperatures recommended for industrial control components: Speed drives50C (with derating) PLCs40C Contactors45C Thermal switches45C Fuses50C Power supply sources35C Electronic charts30 Electrical batteries (storage) 25C Telecommunications equipment40-50C PFC Condensers 50C Circuit breakers if temp > 50C we must declassify Power electronics: high heat dissipation Ideal temp. inside the enclosure most critical component Schneider Electric27- Universal Enclosures Training Course Thermal Management 26.02.2009 Risks linked to lack of TM Electrical components are also affected. Their characteristics and service life are also related to the operating temperature. Abrupt temperature changes inside the environment of the enclosure can cause Thermal stress on the components installed. Thermal stress costs Schneider Electric28- Universal Enclosures Training Course Thermal Management 26.02.2009 Risks linked to lack of TM Faults mean losses Uncontrolled temperature reduces the service life of electrical and electronic switchboards The lack of temperature control may cause production downtime in industrial installations

Schneider Electric29- Universal Enclosures Training Course Thermal Management 26.02.2009 Benefits of a suitable TM Avoid technical downtime with overcost Extend the service life of the installation and the equipment installed Energy saving

Schneider Electric30- Universal Enclosures Training Course Thermal Management 26.02.2009 The importance of the environment Schneider Electric31- Universal Enclosures Training Course Thermal Management 26.02.2009 The importance of the environment Schneider Electric32- Universal Enclosures Training Course Thermal Management 26.02.2009 The importance of the environment Schneider Electric33- Universal Enclosures Training Course Thermal Management 26.02.2009 The importance of the environment Schneider Electric34- Universal Enclosures Training Course Thermal Management 26.02.2009 Thermal study: determine the thermal solution Importance of conducting a THERMAL STUDY prior to installation 110 (enclosure)

(Thermal Solution: 80) 690 610 (equipment: 500) 600 (equipment: 500) 100 (enclosure) Technical downtime excess temperature 800 (new equipment: 200) 950 (thermal sol.: 150)Technical downtime lack maintenance NEW INSTALLATION 1950 (technical downtime: 1000)770(maintenance: 80) Thermal Study Notdone Passive solutionsNot applied Thermal Study done ! Passive solutionsapplied 2ndcompany 1stcompany Schneider Electric35- Universal Enclosures Training Course Thermal Management 26.02.2009 Thermal study : to find out the best thermal solution in project phase Using ProClimaon 1st installation on 2nd installation To keep data from : External and Internal temperatures Humidity And knowing in advance the environment type of the installation Increase reliablity and stability inside the enclosure& Enlarge the lifetime of install components Schneider Electric36- Universal Enclosures Training Course Thermal Management 26.02.2009 Choose the right thermal solution YESYES NO NO Ti Te High powers to be dissipated(>500W)Low powers to be dissipated ( 50Pa Performance of a ventilation system Schneider Electric70- Universal Enclosures Training Course Thermal Management 26.02.2009 VF 56: Motor fan manufacturer: 160m3/h Equipped: 56m3/h (ES catalogue) Analysis of the motor fan AP (Pa) Plastic parts+ filter blanket Motor fan curve AxialCentrifugal Output m3/h 160m3/h56m3/h Centrifugal Axial Schneider Electric71- Universal Enclosures Training Course Thermal Management 26.02.2009 Fans for cooling speed drives Thermal range Precise Heating Schneider Electric73- Universal Enclosures Training Course Thermal Management 26.02.2009 Heating resistances Heat with safety Broad range Innovative design Ease of installation and connection Safety High thermal performance Models with fan Certifications UL, VDE Schneider Electric74- Universal Enclosures Training Course Thermal Management 26.02.2009 Condensation phenomenonProblem risk zones %1 humidity/dew point RH>60% 70%2 Cold ambients 5