Enclosures Dissipated Wattage
| ENCLOSURE DISSIPATED WATTAGE | |||||
|---|---|---|---|---|---|
| Enclosure Type | Temperature Class | ||||
| T6 40°C & T5 55°C | T6 55°C | T5 40°C | T6 65°C | T5 65°C | |
| PL612 GRP | 4.1 | 2.5 | 5.6 | 1.5 | 3 |
| PL615 GRP | 6.4 | 4 | 8.8 | 2.4 | 4.8 |
| PL620 GRP | 11.4 | 7.1 | 15.6 | 4.2 | 8.5 |
| PL626 GRP | 11.4 | 7.1 | 15.6 | 4.2 | 8.5 |
| PL630 GRP | 20.8 | 13 | 28.6 | 7.8 | 15.6 |
| PL712 GRP | 3.352 | 2.148 | 4.6 | 1.2 | 2.4 |
| Size 1 Stainless Steel | 13.95 | 8.7 | 19.1 | 5.2 | 10.4 |
| Size 2 Stainless Steel | 18.15 | 11.3 | 24.9 | 6.8 | 13.6 |
| Size 3 Stainless Steel | 23.7 | 14.8 | 32.5 | 8.8 | 17.7 |
| Size 4 Stainless Steel | 29.95 | 18.7 | 41.1 | 11.2 | 22.4 |
| Size 5 Stainless Steel | 32.85 | 20.5 | 45.1 | 12.3 | 24.6 |
| Size 6 Stainless Steel | 40 | 25 | 55 | 15 | 30 |
| Size 7 Stainless Steel | 52 | 23.5 | 71.5 | 19.5 | 39 |
| Size 8 Stainless Steel | 65 | 40.6 | 89.3 | 24.3 | 48.7 |
| Size 9 Stainless Steel | 79.35 | 49.5 | 109.1 | 29.7 | 59.5 |
Dissipated Wattage Factor
The Dissipated Wattage Factor of the Enclosures has been established by test to ensure that the maximum temperature as permitted by temperature certification is not exceeded. When terminal quantities greater than those at maximum amps are required (up to maximum physical quantity only) then the current shall be reduced accordingly to remain within the Dissipated Wattage Factor of the Enclosure.
Combined Terminal Resistance Factor
This factor is used to determine the number of terminals that can be accommodated within the Enclosure without exceeding the Wattage Factor. The Combined Terminal Resistance Factor is the sum of the individual terminal resistance's and the resistance of the cable core equal in length to the Enclosure maximum diagonal. (Core Resistance is taken from BS6360). Combined terminal resistance factor.
Wattage to be Dissipated = N x F x I²
N = Number of Terminals. F = Combined Terminal Resistance Factor. I = Maximum Current.
e.g. Number of terminals in a PL630 Enclosure at 20.8 Watts - 10 x 'WDU 2.5' (1=21A), 2 x 'WDU 6' (1=36A), (10 x 0.00290465 x 21² = 12.9) + (2 x 0.0012142 x 36² = 3.2 Watts). Total Watts = 12.9 + 3.2 = 16.1 Watts.
Therefore this terminal combination is acceptable as the wattage is less than that of the PL630 maximum Watts of 20.8W.
Note - If a smaller than maximum permitted conductor is fitted into a power terminal, then the smaller conductor resistance must be used when calculating the combined terminal resistance.
Transposed Formula
