Specification

and QOB Miniature Circuit Breakers

General Information

07/2008

General Information

and QOB Circuit Breakers

(plug-on) and QOB (bolt-on) one-, two- and three-pole thermal-magnetic circuit breakers provide

overcurrent protection and switching on ac and dc systems. Plug-on QO circuit breakers are for use in

QO load centers, NQ and NQOD panelboards, OEM mounting bases, and Speed-D

switchboard

distribution panels. Bolt-on QOB circuit breakers are for use in NQO and NQOD panelboards.

Operating mechanism

QO and QOB circuit breakers have an overcenter, trip-free toggle mechanism with quick-make, quick-

break action and positive handle indication. The tripping mechanisms in two-and three-pole circuit

breakers operate such that an overcurrent on any pole of the circuit breaker will cause all poles of the

circuit breaker to open simultaneously. Each pole has an individual thermal-magnetic trip element

calibrated for 40°C ambient temperature.

Trip Indication

QO and QOB circuit breakers have Visi-Trip

trip indication, which provides a visual indication that the

circuit breaker has tripped and interrupted the circuit. When the circuit breaker has tripped, the handle

assumes a center position and the red Visi-Trip indicator appears in a window in the circuit breaker

case. The Visi-Trip indicator is only visible when the circuit breaker has tripped. Trip indication

immediately distinguishes the circuit from any other circuit which is merely in the on or off position. The

circuit breaker can be reset by pushing the handle to OFF and then to ON.

Construction Standards

QO and QOB circuit breakers are built to comply with UL Standard 489, CSA 22.2 No. 5, NOM/ANCE

and NEMA Standard AB1 and to meet Federal Specification W-C-375B/GEN. QO circuit breakers are

UL Listed under UL File E84967 and are CSA Certified under CSA Master Contract 153555.

1 Pole

07303095

2 Pole

07303090

3 Pole

07303091

QO Circuit Breakers

Visi-Trip

Window

07303095

QO Circuit Breaker UL Type

QO280–QO210 QOA, QOB

QO2110–QO2125 QOC, QOCB

QO2150–QO2200 QOC (no bolt-on version)