Siemens / ITE LM3B400 Molded Case Circuit Breaker
- 400A
- 3 Pole
- Bolt-On
Quantity
Siemens / ITE LM3B400 - 400A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
A direct replacement for discontinued LMD frames, the Siemens LM3B400 is a 3-pole, 400A MCCB built for commercial applications. It features a thermal-magnetic trip unit with adjustable magnetic settings. This bolt-on breaker installs into Siemens P4 and P5 panelboards. As a legacy component, it provides an exact fit for older systems and is officially replaced by the LD63B400 for newer installations. Rated for 65kAIC at 240VAC and 25kAIC at 600VAC, it ensures robust fault clearing.Specifications
| Brand | Siemens / ITE |
|---|---|
| Part Number | LM3B400-R |
| Series | LM |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC, 500VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 50kA @ 480VAC, 25kA @ 600VAC, 30kA @ 250VDC, 25kA @ 500VDC |
| Frame Type | LM |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P4, P5 Panelboards, Switchboards |
| Wire Gauge | 1/0 AWG - 500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 1/0 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Lug Kits, Padlock Attachment |
|---|---|
| Accessories | Lugs Not Included |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Interchangeable Trip Unit, HACR Rated |
Product FAQs
6 answersWhich panelboards are compatible with the LM3B400 circuit breaker?
This bolt-on breaker is designed for installation in Siemens P4 and P5 panelboards, as well as compatible Siemens switchboards.
What wire sizes are accepted by the LM3B400 terminals?
The included lugs accept conductor sizes from 1/0 AWG up to 500 kcmil and are dual-rated for both aluminum and copper wire.
How is the trip unit configured on the LM3B400?
It features a thermal magnetic trip unit with a fixed thermal element for long-time overload protection and an adjustable magnetic element for instantaneous short-circuit protection. The adjustable magnetic trip allows for precise coordination with downstream devices.
Can I use the Siemens LM3B400 to replace an older ITE LM3B400?
Yes. Siemens acquired ITE and integrated the Sentron product line. A Siemens LM3B400 is a direct, exact replacement for an older ITE-branded breaker with the same catalog number.
What are the interrupting capacities for DC applications?
For direct current systems, this breaker provides a 30kA interrupting rating at 250VDC and a 25kA interrupting rating at 500VDC.
How does the LM3B400 mount to the panelboard?
It utilizes a bolt-on mounting style, requiring bolted connections directly to the panelboard or switchboard busbars to ensure a secure, low-resistance contact for high-amperage loads.
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