Can a Canadian QO or CHOM, Main Lug Only load center be converted to a Service Entrance approved Main Breaker load center in the field?
Product Design Features
QO and Homeline Canadian load centers
Convertibility of Mains
No. The QO or CHOM Main lugs ONLY load centers CANNOT be converted to a Service Entrance Main Breaker load center in the field. The Canadian code requires the Main Breaker Service Entrance rated load centers, to come bonded with the bonding screw factory installed. Also, the Service Entrance MB load centers contain a Service barrier that prevents load branch wiring from exiting the Mains area. In addition, the Canadian Service Entrance load centers requires additional grounding points, per the code, that a Main lug load center does not contain.
1) A main lug load center could be converted to a main breaker sub-panel using the appropriate QOM1 or QOM2 Main breaker, depending on which MB the load center would use.
2) A main breaker load center can be converted to a main lug load center for use as a sub-panel ONLY, by following the instructions on the label located on the Service Barrier. The label will state "CAUTION: This device is Field convertible to a NON SERVICE ENTRANCE Main Lugs or Main breaker load center when the box bonding screw is removed from the neutral, AND this barrier is discarded".