Power dissipated in Enclosure

The total Power dissipated in the enclosure is the sum of all power dissipated by all components mounted within the enclosure.

In order to calculate/approximate the ventilation required for an enclosure, the power dissipated within the enclosure must be known.

Here are some guidelines for calculating the total power dissipated in the enclosure.

Soft Starter. Allow 4.5 Watts per amp. i.e. MSX 0175 operating at 150 amps, allow 150 x 4.5 = 675 Watts.

Speed Drive. Allow 20 Watts per amp.

Contactor AC3. If dissipation not known, allow 0.15 Watts per Amp contact dissipation, plus 0.1 Watts per amp coil dissipation.

Contactor AC1. If dissipation not known, allow 0.6 Watts per Amp contact dissipation, plus 0.1 Watts per amp coil dissipation.

Thermal overload. If not known, allow:

10 watts if Ie < 32A

18 watts if 32A < Ie < 70A

22 watts if 70A < Ie < 500A

50 watts if Ie > 500A.

Fans. (Not part of starter. i.e. cabinet ventilation fans)


Allow 10 watts for 25mm x 120 mm.

Allow 18 watts for 38mm x 120 mm.

Allow 30 watts for 51mm x 172 mm.

Lamps. Allow 2.5 watts

Fuses.

Type F06. Allow 2 watts per fuse.

Semiconductor Fuses.
Fuse
Soft Starter
Speed Drive
40AFE
2W
10W
80AFE
3W
20W
200FM
7W
40W
350FM
10W
55W
700FMM
22W
120W
Isolators. If not known, allow 0.6 watts per line amp.

Power factor correction capacitors. Refer to data sheet and/or supplier.