Learn the correct sequence: LV off before HV, control before main, and never operate isolators under load. A disconnect box is a localized manual shutoff switch designed to isolate power to a fixed appliance, such as an air conditioning unit, heat pump, or pool equipment. This device is installed near the equipment to provide a convenient, observable point of power interruption for maintenance or. The service disconnect rules, primarily outlined in NEC Article 230, Part VI, are fundamental to electrical safety, providing the means to de-energize an entire building from its power source. For a journeyman electrician or master electrician, a deep understanding of these regulations is. Phase 3's Powersafe Sequential Mating Box controls the connection sequence of incoming / outgoing high current cable connections. With key (included) turn the Earth lock clockwise (Fig. There are long-standing general rules in the National Electrical Code that apply specifically to service disconnects. First open all LV branch circuit breakers, then open the LV main breaker.
[PDF Version]