Siemens LGB3K050B Molded Case Circuit Breaker
- 50A
- 3 Pole
- Bolt-On
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Siemens LGB3K050B - 50A 3 Pole Molded Case Circuit Breaker
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Description
Engineered for commercial power distribution, the Siemens LGB3K050B is a 3-pole, 50-amp molded case circuit breaker from the SENTRON GB family. It provides robust thermal-magnetic overcurrent protection for demanding industrial applications. This bolt-on breaker installs seamlessly into Siemens P1, P2, and P3 panelboards. For newer installations or upgrades, it is officially replaced by the 3VA5150-6ED31-0AA0, which requires a specific mounting strap kit for P1 panels.Specifications
| Brand | Siemens |
|---|---|
| Series | LGB |
| Amperage | 50A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480Y/277VAC, 600Y/347VAC, 125/250VDC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480Y/277VAC, 25kA @ 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, IEC, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, HID Rated, Reverse Feed, Trip-Free Mechanism, Common Trip |
Product FAQs
7 answersWhich Siemens panelboards are compatible with the LGB3K050B circuit breaker?
This bolt-on breaker is designed specifically for installation in Siemens P1, P2, and P3 panelboards. It mounts directly to the panelboard bus to provide reliable branch or main circuit protection.
What frame family does the LGB3K050B belong to?
It is part of the Siemens SENTRON GB frame family. Specifically, it utilizes the GB2 frame design, which is configured exclusively for bolt-on panelboard mounting rather than standard DIN rail or base mounting.
What type of trip unit is installed in the LGB3K050B?
It features a non-adjustable, fixed thermal magnetic trip unit. This provides standard long time and instantaneous overcurrent protection for general commercial and industrial loads.
Can the LGB3K050B be used in direct current applications?
Yes, this breaker is rated for DC systems up to 125/250VDC with a 14kA interrupting capacity. This makes it suitable for specific industrial control or solar applications requiring DC circuit protection.
What wire sizes and conductor materials are accepted by the standard lugs on this breaker?
The factory-installed load lugs accept 8 to 1/0 AWG copper wire or 8 to 2/0 AWG aluminum wire. Ensure you torque the connections to the manufacturer specifications printed on the breaker label.
How does the LGB3K050B mount inside the enclosure?
It utilizes a bolt-on connection type. The line side bolts directly to the panelboard bus, which provides a highly secure, vibration-resistant connection ideal for heavy-duty commercial environments.
Is the LGB3K050B suitable for 480V and 600V commercial distribution systems?
Yes, it is fully rated for 480VAC systems with a 65kA interrupting capacity. It can also be applied to 600Y/347VAC systems where a 25kA interrupting rating is required, making it highly versatile for commercial facilities.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 1 review.
- RSRon S.Verified BuyerReviewingSiemens LGB3B045B - 45A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/27/26Siemens Breaker
The breaker was exactly what I needed, and it came within a couple days. The price was in line of what it should’ve been. This was my third purchase from Super Breakers. I will definitely use them again in the future.