Brochure

PowerPact H-, J-, and L-Frame Circuit Breakers

Automatic Switches

02/2016

Section 4—Automatic Switches

Automatic Switch Functions

An automatic switch can be used to open and close a circuit under normal operating conditions. They

are similar in construction to circuit breakers, except that the switches open instantaneously at a factory-set,

non-adjustable trip point calibrated to protect only the molded case switch.

Molded case switches are intended for use as disconnect devices only. UL489 requires molded case

switches to be protected by a circuit breaker or fuse of equivalent rating. Molded case switches are

labeled with their appropriate withstand ratings. The withstand rating of a switch is defined as the

maximum current at rated voltage that the molded case switch will withstand without damage when

protected by a circuit breaker with an equal continuous current rating.

PowerPact™ H-, J-, and L-frame automatic switches are available in unit mount, I-Line™, plug-in and

drawout versions. They use the same accessories and offer the same connection possibilities as the

circuit-breaker versions. They may be interlocked with another switch or circuit breaker to form a

source-changeover system.

Switches are Listed under UL file E103740 and Certified under CSA file LR88980.

Motor Operator

PowerPact H-, J-, and L-frame switches equipped with a motor operator module allow remote closing

and opening.

Ground Fault Protection (H- and J-Frame Circuit Breakers Only)

An ELM or GFM module may be added to an automatic switch to monitor all leakage currents in the

outgoing circuits of the equipment on which the automatic switch is installed. When the ELM or GFM

module detects an earth-leakage current, the automatic switch interrupts the load current.

Automatic Switch Protection

The automatic switch can make and break its rated current. For an overload or a short-circuit, it must

be protected by an upstream device, in compliance with installation standards. Due to their high-set

instantaneous release PowerPact H-, J- and L-frame automatic switches are self-protected.