Siemens / ITE LM3B350 Molded Case Circuit Breaker
- 350A
- 3 Pole
- Bolt-On
Quantity
Siemens / ITE LM3B350 - 350A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Built for heavy-duty commercial and industrial environments, the Siemens LM3B350 delivers reliable 350A thermal-magnetic protection. It handles demanding electrical loads across various facility applications. This bolt-on MCCB is engineered to fit seamlessly into Siemens P4 and P5 panelboards. As a legacy component, it serves as an exact replacement, though it has been officially replaced by the LD63B350. It features a 65kAIC rating at 240V and an interchangeable trip unit.Specifications
| Brand | Siemens / ITE |
|---|---|
| Part Number | LM3B350-R |
| Series | LM |
| Amperage | 350A |
| 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
8 answersWhich Siemens panelboards are compatible with the LM3B350 circuit breaker?
This breaker is designed for use in Siemens P4 and P5 panelboards, as well as compatible Siemens switchboards.
What type of wire can be used with the terminals on the LM3B350?
The factory lugs accept both aluminum and copper conductors ranging from 1/0 AWG to 500 kcmil.
How does the trip unit operate on this LM frame breaker?
It features a thermal magnetic trip unit with fixed thermal protection for overloads and an adjustable magnetic setting to customize the instantaneous short-circuit response.
Is the LM3B350 suitable for direct current (DC) systems?
Yes, it supports DC applications with interrupting ratings of 30kA at 250VDC and 25kA at 500VDC.
Are ITE and Siemens LM3B350 breakers the same product?
Yes. Siemens acquired ITE, and the LM3B350 is part of the Siemens Sentron family of LMD frame circuit breakers. They are functionally identical and share the same catalog number.
What does the LI designation mean on the LM3B350 trip unit?
LI indicates Long-Time and Instantaneous protection. The long-time function prevents damage from sustained overloads, while the instantaneous function trips immediately during a short circuit.
How is the LM3B350 secured inside the panelboard?
It utilizes a bolt-on mounting style, requiring bolted connections to the panel busbars for a secure, high-amperage electrical connection.
What is the maximum interrupting capacity for this breaker on a 480V AC system?
When installed in a 480VAC system, the breaker provides a 50kA interrupting capacity (AIC) to safely clear faults.
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