EXTENDED MAJOR APPLIANCE CIRCUIT

J.  EXTENDED MAJOR APPLIANCE CIRCUIT:
Major appliance circuits are intended to serve only one appliance.  The wire is to be run directly from the appliance to the panel.  Sometimes amateurs will feed several major appliances from the same circuit.  This often happens when basement apartments are installed.

It is often allowable for an oven and a cooktop to be fed from the same circuit, but in some cases it is not.  This is determined by the manufacturer and is specific to the equipment in question.

Often, in older houses, where it is difficult to run new wire from the main panel or there is no expansion room with in the main panel, the extra appliance (Fig. J1, Item C) will be electrified by tapping into an existing major appliance circuit (Fig. J1, Item A). 

Fig. J1

The risk is that the added wire will be too small to carry the load allowed by the circuit breaker (Fig. J1, Item B) or fuse that was used to protect the original major appliance (Fig. J1, Item D).  This “over fusing” of the newly added appliance and its associated wire presents a risk of fire or human contact with electricity, should the insulation fail due to overload.

WHAT TO:  HOW TO:
An additional circuit will have to be run from the new major appliance back to the main panel.  If there is no expansion room within the panel, a heavy up with greater distribution capability or the addition of a sub-panel may be the only remedy.

REFERENCE: E1, E2, E5