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Siemens LGB2B045B Molded Case Circuit Breaker
- 45A
- 2 Pole
- Bolt-On
Siemens
LGB2B045B
Molded Case Circuit Breaker
Brand
Siemens
SKU
LGB2B045B
Quantity
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Siemens LGB2B045B - 45A 2 Pole Molded Case Circuit Breaker
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Description
Part of the Sentron series, the Siemens LGB2B045B is a 2-pole, 45A molded case circuit breaker engineered for commercial power distribution. It features a fixed thermal-magnetic trip unit for reliable LI protection. This bolt-on MCCB installs into Siemens P1, P2, and P3 panelboards. For upgrades, it is replaced by the 3VA4145-6ED24-0AA0 (mounting kit required). Rated for 100kAIC at 240V and 65kAIC at 480Y/277V, this HACR-rated breaker includes load-side lugs for reverse feed applications.Specifications
| Brand | Siemens |
|---|---|
| Part Number | LGB2B045B |
| Series | LGB |
| Amperage | 45A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480Y/277VAC, 600Y/347VAC, 125/250VDC |
| Phase | 1 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480Y/277VAC, 14kA @ 600Y/347VAC, 14kA @ 125/250VDC |
| Frame Type | LGB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3 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, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, HID Rated, Reverse Feed, Trip-Free Mechanism, Non-Interchangeable Trip, High Interrupting Capacity |
Product FAQs
7 answersWhat panelboards are compatible with the LGB2B045B?
This bolt-on circuit breaker is designed for direct installation in Siemens P1, P2, and P3 panelboards. It mounts directly to the panelboard bus for branch circuit applications.
Can the LGB2B045B be used in DC applications?
Yes, this breaker is rated for use in direct current systems up to 125/250V DC, providing an interrupting capacity of 14kA for specific control or distribution circuits.
What wire sizes are accepted by the lugs on this breaker?
The standard factory lugs accept 8 to 1/0 AWG copper wire or 8 to 2/0 AWG aluminum wire. Always ensure proper torque specifications are met during installation.
What is the difference between Siemens NGB, HGB, and LGB frame breakers?
The primary difference is their short-circuit interrupting ratings. The LGB frame offers the highest interrupting capacity in this family, rated at 65kA at 480/277V AC, compared to the lower-rated NGB and HGB frames. They share the same physical footprint and panelboard compatibility.
What does the LI trip function indicate on this breaker?
The LI designation means the breaker uses a thermal-magnetic trip unit providing Long-Time (L) protection against overloads and Instantaneous (I) protection against short circuits. Both trip settings are fixed and non-adjustable.
Does this breaker require a separate mounting kit for P1 panelboards?
When installing in an original Siemens P1 panelboard as a main or subfeed breaker, a specific mounting hardware kit, such as the MBKNB1 or MBKNB3, is required. For standard branch circuit positions, it bolts directly to the bus.
Can this breaker be mounted on a standard DIN rail?
No, the LGB2B045B is specifically configured with a bolt-on line end for panelboard mounting. For DIN rail applications, a standard GG frame breaker is required instead of the panelboard-specific GB or LGB frame.
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