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Siemens BL series 40A single-pole bolt-on breaker grey toggle

SIEMENS

SIEMENS B140 Miniature Circuit Breaker BL Series 40A 1 Pole 120/240V AC

SKU CH-1588-S7T6K

A 40-amp single-pole breaker rated for 120/240V AC with a 10kA interrupting rating and bolt-on mounting for Siemens P1 panelboards

  • 40 A rated current protects single-phase circuits up to 40 A
  • 10 kA interrupting capacity clears faults safely at 120/240 V AC
  • Bolt-on mounting fits Siemens P1 panelboards directly
  • Toggle actuator gives clear on/off indication
  • Accepts 8–6 AWG wire for flexible installation

SIEMENS BL 40A Single-Pole Breaker

This SIEMENS B140 miniature circuit breaker is a bolt-on, single-pole device rated at 40A and 120/240V AC. It belongs to the BL series with a 125A frame size and fits Siemens P1 panelboards. The toggle actuator provides standard manual switching for branch-circuit protection.

Who this suits and who should look elsewhere

Electricians and facility managers protecting a 40A single-phase branch circuit in a compatible P1 load center will find the correct ratings and mounting style here. Installations requiring a two-pole breaker, a different amperage, a plug-on mounting method, or a panelboard series other than P1 are not addressed by this device.

The deciding specification: 10kA AIR at 120/240V AC

The maximum interrupting rating of 10kA at 120/240V AC determines whether this breaker can safely clear a fault on your system. Verify that the available fault current at the point of installation does not exceed this value before selecting the B140.

How it compares

Measured against everything we stock in Breakers & Circuit Protection, at today’s prices. Recalculated every night.

Price $47.99
Cheaper than about 57% of the 1,135 comparable items (median $54.99).

Specifications

Product
Brand nameSIEMENS

Questions about this item

Will the bolt-on mounting fit a Siemens P1 panelboard?

Yes, the breaker is designed for bolt-on installation in Siemens P1 panelboards and load centers.

What wire sizes can the lug terminals accept?

The lug terminals accept copper conductors from 8 AWG minimum to 6 AWG maximum.

What interrupting rating does the breaker provide?

The breaker delivers a maximum AIR rating of 10kA at 120/240V AC.

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