Siemens LGB3K020B Molded Case Circuit Breaker
- 20A
- 3 Pole
- Bolt-On
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Siemens LGB3K020B - 20A 3 Pole Molded Case Circuit Breaker
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Description
Built for commercial applications, the Siemens LGB3K020B is a 3-pole, 20A molded case circuit breaker from the SENTRON family. It features a thermal-magnetic trip unit with fixed long-time and instantaneous functions. This bolt-on breaker installs into Siemens P1, P2, and P3 panelboards. For maintenance, it serves as a direct replacement, though newer 3VA4 frames require a mounting kit. Rated 65kAIC at 480Y/277V, this LGB frame is HACR and HID rated for demanding electrical loads.Specifications
| Brand | Siemens |
|---|---|
| Series | LGB |
| Amperage | 20A |
| 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 | 14-6 AWG (Cu), 12-6 AWG (Al) |
| Max Wire | 6 AWG |
| Min Wire | 14 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 Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, UL 489 |
| Approval | CSA, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Reverse Feed, HID Rated |
Product FAQs
7 answersWhich Siemens panelboards accept the LGB3K020B circuit breaker?
This bolt-on breaker is specifically designed for installation in Siemens P1, P2, and P3 series distribution panelboards. It is not compatible with standard residential load centers.
What are the lug torque specifications for the LGB3K020B?
For this 20A breaker, the factory lugs should be torqued to 35 lb-in when using 14-10 AWG conductors, and 40 lb-in when using 8 AWG conductors.
What wire sizes are supported by the standard lugs on this breaker?
The standard mechanical lugs accept 14 to 6 AWG copper wire or 12 to 6 AWG aluminum wire.
Is the LGB3K020B rated for direct current (DC) circuits?
Yes, the thermal-magnetic trip unit is suitable for DC applications. It carries a 14kAIC interrupting rating at 125/250VDC.
Can this breaker be installed on 600V wye systems?
Yes, the LGB3K020B is rated for 600Y/347VAC solid-grounded wye systems, providing up to 25kAIC of fault protection at that voltage.
Are the trip settings adjustable on the LGB3K020B?
No, this breaker features a fixed thermal and fixed magnetic trip unit. Both the long-time and instantaneous (LI) protection functions are factory calibrated and non-adjustable.
What frame size is the LGB3K020B?
It is built on the Siemens Sentron LGB frame, which is part of the broader GB/GG frame family of compact industrial circuit breakers.
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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.