Prisma Plus LV Switchboards - POWERLAB

Thermal characteristicsSystem GThermal managementof switchboardsComparative methodCharacteristicsTwo cubicles with busbar compartment, 800 mmwide, 1000 mm deep, two 300 mm wide ducts, IP30Diversity factor: 0.7Ambient temperature around the switchboard: 35°CCubicle 1 : P(W) of device zone = 580 WCubicle 2 : P(W) of device zone = 180 WDD382421Application of the diversity factor In the configuration below, the standardised diversity factor (K div.) for a total of 14outgoing circuits is 0.6, i.e. 60 % of In for each outgoing circuit.Merlin Gerin prefers a more conservative approach and therefore divides theinstallation into four main circuits:b NS250b 200 A Multiclip: 8 outgoers V K div. = 0.7b Polypact: 4 outgoers V K div. = 0.8b NS400.1 NS250 + 1 Multiclip 200 A + 1 Polypact + 1 NS400 V 4 outgoers, i.e. a diversityfactor of 0.8.As a result, the current flowing in each circuit is at least 70% and up to 80% of In.Calculation of the power dissipated bydevices in the incoming cubicleDissipated power of the NT1600 indicated by the manufacturer: 460 W.The power dissipated by the connections is approximately 30% of the device P(W):0.3 x 460 = 138 W.Power of circuit breaker + connections = 460 + 138 = 598 W at 1600 A.For I² (the Watts are proportional to the square of the current) at 1410 A (In of theincoming device):598-------------- × 1410 2 405 W1600 2 =Dissipated power of the NS250 indicated by the manufacturer: 42 W.Dissipated power of the connections: 0.3 x 42 = 12.6 W.Power of circuit breaker + connections = 42 +12.6 = 54.6 W at 250 A.For 200 A (the tested value):54,6----------- × 200 2 = 35 W250 2Dissipated power of the Polypact and its four NS250 circuit breakers:4 x 35 W (same calculation as above) = 140 WSum of the dissipated power in the incoming cubicle:P(W) = 405 + 35 +140 = 580 W172