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Siemens Q120 miniature circuit breaker, single pole toggle, light grey plastic body, plug-in mount

SIEMENS

SIEMENS Q120 Miniature Circuit Breaker 20A 1 Pole 120V AC 10kA

SKU CH-064D-FBXQC

Protects 120 V AC single-phase circuits with a 20 A plug-in breaker rated for 10 kA interrupting capacity

  • 20 A single-pole protection for 120 V AC circuits
  • 10 kA interrupting rating handles high fault currents
  • Plug-in mounting fits Siemens EQ load centers directly
  • Lug terminals accept 14 to 10 AWG conductors
  • Compact 3.5 × 1.3 × 3.15 in frame saves panel space

Single-Pole 20A Protection

The Siemens Q120 is a single-pole miniature circuit breaker rated at 20 amps for 120V AC systems. It plugs into compatible Siemens EQ load centers and provides standard overcurrent protection for residential branch circuits. The 10kA interrupting rating handles typical household fault currents.

Plug-In Mounting and Lug Terminals

The plug-in mounting style allows quick installation without bolt-down hardware in EQ-series panels. A built-in lug terminal accepts copper conductors from 14 AWG up to 10 AWG, simplifying wire connections for electricians. No separate accessories or software are included with the breaker itself.

120V AC Only with 10kA Limit

This breaker carries no DC voltage rating, so it cannot protect direct-current circuits such as solar arrays or battery banks. The maximum interrupting capacity is 10kA at 120V AC; systems with higher available fault current require a different device. The single-pole design occupies one panel space and suits 120V loads only.

How it compares

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

Price $7.99
Cheaper than about 95% of the 1,135 comparable items (median $54.99).

Specifications

Product
Brand nameSIEMENS

Questions about this item

Will the lug terminals on this 20 A breaker need re-torquing after the first few weeks of service?

The lug terminals accept 14 to 10 AWG wire and are designed to maintain clamping force without scheduled re-torquing under normal operation.

At what current does the 10 kA interrupting rating become the limiting factor during a prolonged overload?

The breaker will trip on its thermal-magnetic curve well before the 10 kA short-circuit rating is reached; that rating only applies to fault currents.

How warm does the Q120 get when it carries 20 A continuously in a closed panel?

The 125 A frame size and plug-in mounting keep temperature rise within UL limits for continuous 20 A loads in a Siemens EQ load center.

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