Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Siemens HGB2B125B Molded Case Circuit Breaker
- 125A
- 2 Pole
- Bolt-On
Siemens
HGB2B125B
Molded Case Circuit Breaker
Brand
Siemens
SKU
HGB2B125B
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Siemens HGB2B125B - 125A 2 Pole Molded Case Circuit Breaker
New
Quantity
Similar Items
90A 2 Pole Molded Case Circuit Breaker
80A 2 Pole Molded Case Circuit Breaker
125A 3 Pole Molded Case Circuit Breaker
Description
Built for commercial applications, the Siemens HGB2B125B is a 2-pole, 125A MCCB from the Sentron GB frame family. This bolt-on breaker installs into Siemens P1 through P5 panelboards. It is replaced by the 3VA5112-6ED21-0AA0, which requires a separate mounting kit for panel integration. Rated at 100kAIC at 240V and 35kAIC at 480Y/277V, it handles significant fault currents. It features fixed thermal-magnetic trip functions and an HACR rating.Specifications
| Brand | Siemens |
|---|---|
| Series | HGB |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480Y/277VAC, 600Y/347VAC, 125/250VDC |
| Phase | 1 |
| AIC Rating | 100kA @ 240VAC, 35kA @ 480Y/277VAC, 14kA @ 600Y/347VAC, 42kA @ 125/250VDC |
| Frame Type | HGB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3, P4, P5 Panelboards |
| Wire Gauge | 8-1/0 AWG (Cu), 8-2/0 AWG (Al) |
| Max Wire | 1/0 AWG (Cu), 2/0 AWG (Al) |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, IEC, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Reverse Feed, High Interrupting Capacity |
Product FAQs
8 answersWhich Siemens panelboards accept the HGB2B125B circuit breaker?
The HGB2B125B is designed for bolt-on installation in Siemens P1, P2, P3, P4, and P5 series panelboards that are configured with xGB branch unit space.
What wire sizes are compatible with the factory lugs on the HGB2B125B?
The standard lugs accept 8 to 1/0 AWG copper (Cu) conductors or 8 to 2/0 AWG aluminum (Al) conductors.
What does the H in the HGB frame designation mean?
The H indicates a high interrupting rating. The HGB2B125B provides up to 100kAIC at 240VAC and 35kAIC at 480/277VAC, offering higher fault current protection than standard NGB or GB frames.
How does the HGB2B125B mount into the panelboard?
This breaker features a bolt-on connection, securing directly to the panelboard bus. This provides a secure, vibration-resistant connection suitable for commercial and industrial environments.
How does the trip unit on the HGB2B125B operate?
It utilizes a fixed thermal-magnetic trip unit with Long-Time and Instantaneous (LI) functions. The thermal component responds to prolonged overloads, while the magnetic component provides immediate tripping during short circuits.
Is there a newer replacement for the HGB2B125B?
Yes, Siemens is transitioning from the legacy GB frame to the 3VA series. The direct replacement is the 3VA5112-6ED21-0AA0, but note that installing a 3VA breaker into an existing panelboard requires a separate mounting kit.
Can the HGB2B125B be used in direct current (DC) systems?
Yes, in addition to its AC ratings, this breaker is rated for DC applications with an interrupting capacity of 42kAIC at 125/250VDC.
Can the HGB2B125B be installed in the same unit space as BQD or BL breakers?
No, xGB frame breakers like the HGB2B125B have different physical dimensions and cannot be mixed in the same mounting space as BQD or BL frames. The panelboard must have dedicated xGB branch unit space.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
100 SuperPoints = $1 off.
Warranties
Add an extra year of protection
60-Day Warranty
Your purchase includes 60 days of SuperBreakers warranty coverage.
Add a 1-year warranty extension in your cart.
Get a Quote
Don’t see what you’re looking for?
We source obsolete and hard-to-find parts every day.
Shipping
Free Shipping Policy
Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
Same Day Shipping
We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.
Expedited Shipments
Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.
International Shipping
All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.