ABB / General Electric THHQB2120ST1 Miniature Circuit Breaker
- 20A
- 2 Pole
- Bolt-On
Quantity
ABB / General Electric THHQB2120ST1 - 20A 2 Pole Miniature Circuit Breaker
New
Quantity
Description
Part of the Q-Line family, this 20A two-pole breaker is engineered for commercial power distribution. It utilizes reliable thermal-magnetic trip technology to protect circuits from overloads. This unit installs into GE A-Series and AQ lighting panelboards. The bolt-on mounting style ensures a rigid, secure connection to the busbar, maintaining stability in demanding environments. Rated 22kAIC at 120/240VAC, it includes a factory-installed shunt trip for remote operation and is HACR rated.Specifications
| Brand | ABB / General Electric |
|---|---|
| Series | THHQB |
| Amperage | 20A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 22kA @ 120/240VAC |
| Frame Type | THQB |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | GE A-Series Panelboards, GE AQ Lighting Panels |
| Wire Gauge | 14-8 AWG (Cu), 12-8 AWG (Al) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG (Cu), 12 AWG (Al) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Accessories | Shunt Trip |
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Internal Common Trip, Quick-Make/Quick-Break, Non-Interchangeable Trip |
Product FAQs
7 answersWhich panelboards accept the THHQB2120ST1 circuit breaker?
This bolt-on breaker is specifically designed for GE A-Series panelboards and GE AQ lighting panels. It will not fit in standard residential load centers that require plug-on connections.
What distinguishes the THHQB series from standard THQB breakers?
The extra H in the THHQB part number designates a high interrupting capacity. This model provides a 22kAIC rating, whereas standard THQB breakers are typically rated for 10kAIC.
What function does the ST1 suffix provide on the THHQB2120ST1?
The ST1 suffix indicates the breaker includes a factory-installed shunt trip accessory. This allows for remote tripping of the circuit breaker via an external voltage signal, which is often required for emergency stop or safety interlock circuits.
Why might this breaker arrive with ABB branding instead of GE?
ABB acquired GE Industrial Solutions. As a result, Q-Line breakers like the THHQB2120ST1 may feature either ABB or General Electric labels, but the form, fit, and internal components are identical.
Can I substitute a THHQL breaker for this THHQB model?
No. While both are Q-Line breakers with a 22kAIC rating, the THHQB is a bolt-on breaker for commercial panels, and the THHQL is a plug-on breaker for residential load centers. They are not physically interchangeable.
What type of wire can be used with the THHQB2120ST1 box lugs?
The breaker terminals accept both copper and aluminum wiring. You can use 14 to 8 AWG copper conductors or 12 to 8 AWG aluminum conductors.
Does the THHQB2120ST1 provide ground fault or arc fault protection?
No. This is a standard thermal-magnetic breaker equipped with a shunt trip. It does not include GFCI or AFCI capabilities.
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