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What size wire can be used in QO and QOB circuit breakers (10-125A; 1-, 2- and 3-pole), solid or stranded?

Issue:
For the lugs of QO and QOB circuit breakers, 10A through 125A, what range of wire sizes can be used? Is it OK to use solid or stranded wire?

Product Line:
Circuit Breakers

Environment:
The following applies to QO and QOB circuit breakers, 1-, 2- and 3-poles, 10A through 125A.
Does not apply to QOT or QOU breakers.
Does not apply to breakers with suffix GFI, AFI, CAFI, DF, EPD, or EPE.
Does not apply to accessory terminal wire size.

Cause:
There is a need to know the size and type of wire that can be used in the lugs of QO and QOB circuit breakers.

Resolution:
QO and QOB breakers, 1-, 2- and 3-poles, are UL Listed and rated to accept the following wire sizes, solid or stranded (type B or C).

10A - 30A - Either of the the following:
  • 1 wire per lug:  (1) #14 - #8 AWG Aluminum or Copper
  • 2 wires per lug: (2) #14 - #10 AWG Copper

35A - 70A
  • 1 wire per lug: (1) #8 - #2 AWG Aluminum or Copper

80A-125A
  • 1 wire per lug: (1) #4 AWG - 2/0 kcmil Aluminum or Copper
  • QOB2110VH, QOB2125VH, QOB3110VH and QOB3125VH circuit breakers accept one wire per lug (1) #4 AWG - 300 kcmil Aluminum or Copper
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