Circulator Water Pump Fusible

Per NEC 422.33(A), a fusible disconnect is required for pumps rated over 1/2 hp (horsepower).

Unfusible

If the pump is rated 1/2 hp or less, an unfusible disconnect is acceptable.

Water Heater Fusible

Per NEC 422.33(B), a fusible disconnect is required for water heaters that require more than 125 amperes or a rating of 50 kW or more.

Unfusible

If the water heater does not meet the above criteria, an unfusible disconnect is acceptable.

Additional Considerations

Fusible disconnects must have a fuse size appropriate for the equipment's current rating. Unfusible disconnects must be clearly marked with the equipment's maximum current rating. All disconnects should be readily accessible and located within sight of the equipment they serve.Therefore, for:

Circulator water pumps over 1/2 hp

Fusible disconnect required

Circulator water pumps 1/2 hp or less

Unfusible disconnect acceptable

Water heaters over 125 amperes or 50 kW

Fusible disconnect required*

Water heaters below 125 amperes and 50 kW: Unfusible disconnect acceptable Flag for review