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Siemens LGB1B040B Molded Case Circuit Breaker
- 40A
- 1 Pole
- Bolt-On
Siemens
LGB1B040B
Molded Case Circuit Breaker
Brand
Siemens
SKU
LGB1B040B
Quantity
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Siemens LGB1B040B - 40A 1 Pole Molded Case Circuit Breaker
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Description
Belonging to the Siemens Sentron family, this 1-pole, 40A MCCB is built for commercial and industrial power distribution. It provides reliable thermal-magnetic protection for branch circuits. The bolt-on unit installs into Siemens P1, P2, and P3 panelboards. While part of the legacy GB/GG frame lineup, it serves as a crucial component before transitioning to the newer 3VA41 series. It features a robust 65kAIC rating at 277VAC and is both HACR and HID rated for versatile applications.Specifications
| Brand | Siemens |
|---|---|
| Part Number | LGB1B040B |
| Series | LGB |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 277VAC, 125VDC, 347VAC |
| Phase | 1 |
| AIC Rating | 100kA @ 120VAC, 65kA @ 277VAC, 14kA @ 125VDC, 14kA @ 347VAC |
| Frame Type | G |
|---|---|
| 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 |
| 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, Padlock Attachment, Handle Tie |
|---|---|
| Accessories | Load Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, UL 489 |
| Approval | CE, CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, HID Rated, Trip-Free Mechanism, Non-Interchangeable Trip |
Product FAQs
5 answersWhich panelboards are compatible with the LGB1B040B circuit breaker?
This bolt-on G-frame breaker is designed for use in Siemens P1, P2, and P3 panelboards. It requires a bolted connection to the bus and is not compatible with standard load centers that use plug-on breakers.
Can the LGB1B040B be used in DC applications?
Yes, this breaker is rated for up to 125VDC with an interrupting capacity of 14kA. This makes it suitable for specific industrial control circuits and battery backup applications requiring DC overcurrent protection.
Is the LGB1B040B suitable for reverse feed applications?
Yes, Siemens thermal-magnetic G-frame breakers like the LGB1B040B are suitable for reverse feeding. They do not have fixed Line and Load markings, allowing power to be supplied from either direction.
What is the difference between Siemens LGB, NGB, and HGB breakers?
The primary difference is the interrupting rating. Within the Siemens G-frame family, NGB has the standard interrupting capacity (25kA at 277V), HGB has a high interrupting capacity (35kA at 277V), and LGB provides the highest interrupting capacity (65kA at 277V). All three share the same physical footprint and panelboard compatibility.
What is the recommended lug torque for the LGB1B040B?
For standard 35A to 125A G-frame lugs, the recommended torque is 40 lb-in for 8 AWG wire, 45 lb-in for 6 to 4 AWG wire, and 55 lb-in for 3 to 1/0 AWG wire. Always verify the exact torque specifications printed on the side of the breaker before terminating conductors.
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