Data Bulletin
0600DB0401
05/2005
Cedar Rapids, IA, USA
Replaces D-471 09/1987
Push-to-trip
Class 0600
Retain for future use.
NEMA AB 4
The National Electrical Manufacturers Association (NEMA) Standards
Publication No. AB 4 states that “Good practice includes periodic circuit
breaker maintenance during plant shutdown or during a regular
maintenance procedure.” NEMA AB 4 sets forth a number of basic
procedures “that may be used for the inspection and preventive
maintenance of molded case circuit breakers used in industrial and
commercial applications rated up to and including 1000 V 50/60 Hz AC or
AC/DC.”
One of these procedures is “For breakers that are provided with mechanical
trip provisions (generally indicated by a test button) operate the tripping
means according to the manufacturer’s instructions.” Square D
recommends that circuit breakers be tripped annually to exercise the circuit
breaker mechanism. The frequency should be increased if severe
environmental conditions exist.
PUSH-TO-TRIP
All Square D industrial circuit breakers have an easily identified yellow or
red push-to-trip button, found on the circuit breaker cover, to provides a
means to mechanically trip the circuit breaker. The push-to-trip button can
be conveniently depressed with a pen or pencil. The action will cause the
circuit breaker to “trip”, opening the contacts.
When the push-to-trip button is depressed, the operating handle on all
Square D industrial switches and circuit breakers assume a distinctive
tripped position. To reset the circuit breaker, move the handle to the
extreme “OFF” position and then to the “ON” position.
The entire operation should be repeated several times. This action
exercises the latches and tripping portion of the mechanism and allows
maintenance checks on the circuit breakers, control circuits, and other
associated equipment.
The push-to-trip function is the only practical way to check the operation of
an optional alarm switch accessory. The alarm switch is activated only when
the circuit beaker is tripped.
The push-to-trip function exercises the actual latching-delatching
components of the mechanism. These are some of the same mechanism
components utilized during a tripping operation. Using the push-to-trip
function during maintenance activities provides assurance that the circuit
breaker mechanism is operational.
In many cases, the trim does not need to be removed to use the push-to-trip
function. When performing tests on electrical equipment, it is desirable to
have the equipment de-energized, disconnected and isolated.
I f the circuit breaker being tested is not de-energized, operating the pushto-trip function will break the circuit and interrupt current to all downstream
equipment. Steps should be taken to minimize the electrical interruption and
to ensure proper start of equipment when the circuit breaker is turned ”ON”.
1
Push-to-trip
Data Bulletin
0600DB0401
05/2005
Typical locations of the push-to-trip button is shown in the accompanying
illustrations.
For more information on inspection and maintenance of circuit breakers,
see Square D Bulletin SD363, Field Testing Industrial Molded Case Circuit
Breakers.
05200017
06603040
Typical Push-to-trip Locations
05253173
Figure 1:
ON
OFF
Push-to-trip Button
Schneider Electric USA
3700 Sixth St. SW
Cedar Rapids, IA 52404 USA
1-888-SquareD (1-888-778-2733)
www.us.SquareD.com
Electrical equipment should be installed, operated, serviced, and maintained only by
qualified personnel. No responsibility is assumed by Schneider Electric for any
consequences arising out of the use of this material.
© 2005 Schneider Electric All Rights Reserved