Equipment Heat Gain

Heat gain from switchgear, transformers, motors ..

Heat gain from electrical equipment are indicated below: 

• Transformers

  • 150 kVA and smaller : 50 Watts/kVA
  • 150 - 500 kVA : 30 Watts/kVA
  • 500 - 1000 kVA : 25 Watts/kVA
  • 1000 - 2500 kVA : 20 Watts/kVA
  • larger than 2500 kVA : 15 Watts/kVA

  Switchgear

  • Low voltage breaker 0-40 Amps : 10 Watts
  • Low voltage breaker 50-100 Amps : 20 Watts
  • Low voltage breaker 225 Amps : 60 Watts
  • Low voltage breaker 400 Amps : 100 Watts
  • Low voltage breaker 600 Amps : 130 Watts
  • Low voltage breaker 800 Amps : 170 Watts
  • Low voltage breaker 1600 Amps : 460 Watts
  • Low voltage breaker 2000 Amps : 600 Watts
  • Low voltage breaker 3000 Amps : 1100 Watts
  • Low voltage breaker 4000 Amps : 1500 Watts
  • Medium voltage breaker/switch 600 Amps : 1000 Watts
  • Medium voltage breaker/switch 1200 Amps : 1500 Watts
  • Medium voltage breaker/switch 2000 Amps : 2000 Watts
  • Medium voltage breaker/switch 2500 Amps : 2500 Watts

  Motor Control Centers

  • Section : 500 Watts per section
  • Low voltage starters size 00 : 50 Watts
  • Low voltage starters size 0 : 50 Watts
  • Low voltage starters size 1 : 50 Watts
  • Low voltage starters size 2 : 100 Watts
  • Low voltage starters size 3 : 130 Watts
  • Low voltage starters size 4 : 200 Watts
  • Low voltage starters size 5 : 300 Watts
  • Low voltage starters size 6 : 650 Watts
  • Medium voltage starters size 200 Amp : 400 Watts
  • Medium voltage starters size 400 Amp : 1300 Watts
  • Medium voltage starters size 700 Amp : 1700 Watts

  Variable Frequency Drive

  • Variable frequency drive : 2 - 6% of kVA rating
  • Bus duct : 0.015 Watts /ft Amp
  • Capacitors : 2 Watts / KVAR