Q. Can a 100-amp service panel be used with a 60-amp incoming service?

A.Eric Lewis responds: The answer is a conditional "Yes." The service rating for a panel comprises the amp rating of both the incoming feed conductor and the overcurrent device. Typically, overcurrent protection is provided by the service panel’s main breaker or a fused switch. A service panel main breaker rated at 100 amps would trip only after the service load exceeded 100 amps. Since this is well above the 60-amp capacity of the service wire, the incoming service cable would not be properly protected.

However, if you install a 100-amp main lug panel and outfit it with 60-amp main breaker, the 60-amp source conductor will be properly protected. It is also important to install a retainer clip to prevent the 60-amp breaker from accidentally becoming dislodged.

Eric Lewis owns and operates Spectrum Electrical Services in Montrose, Pa.