CODE AND PANELBOARD INSTALL

[MURALS]

A 45KVA 3 phase transformer ( 480/208-120) has 70 amp primary protection. 150 amps Secondary breaker size in the panelboard which 3phase, 208/120, 4 wire, 100Amps. The panel is within 10 feet of transformer. Is this OK as per code? I think that the breaker size in the panel should be 100 Amps and not 150 Amps as the Panelboard is rated for 100 amps. Any comments?

 

[jap]

A 45KVA 3 phase transformer ( 480/208-120) has 70 amp primary protection. 150 amps Secondary breaker size in the panelboard which 3phase, 208/120, 4 wire, 100Amps. The panel is within 10 feet of transformer. Is this OK as per code? I think that the breaker size in the panel should be 100 Amps and not 150 Amps as the Panelboard is rated for 100 amps. Any comments?

The transformer is perfectly capable of supplying a 150 amp 3ph 120/208v panel, however, if a 100 amp rated panel was used instead of a 150 amp rated panel, then, the OCPD must be sized at 100 amps or less to protect the rating of the max rating of the panel.

JAP>

 

[don_resqcapt19]

408.36 is the code reference for the required panel protection.