Designed for heavy-duty power distribution, the Siemens CM3B500 is a 500A, 3-pole current-limiting circuit breaker. It provides reliable thermal-magnetic trip functions for industrial facilities. This bolt-on MCCB installs into Siemens switchboards, power panelboards, and motor control centers. As a legacy component, it offers a precise fit for older systems and is officially replaced by the CMD63B500. Amp-trap limiters restrict fault currents, achieving a 100kAIC rating at 480VAC.
Load Side Lugs Included, Amp-trap Current Limiters
Standards
UL 489, CSA C22.2 No. 5
Approval
CSA, UL
Temp Rating
40C
Construction Features
Current Limiting, Fused Protection, Interchangeable Trip Unit
Special Features
Current Limiting (Integrally Fused)
Product FAQs
5 answers
Which Siemens equipment is compatible with the CM3B500 circuit breaker?
This bolt-on breaker is designed for installation in Siemens switchboards, motor control centers, and power panelboards that accept C-frame molded case circuit breakers.
What are the wire size requirements for the load side lugs on this breaker?
The factory-installed load side lugs accommodate three conductors per phase, accepting wire sizes from 1/0 AWG up to 500 kcmil. Ensure proper torque specifications are followed during installation.
How does the current-limiting feature of the CM3B500 benefit the electrical system?
As a current-limiting breaker, it clears faults extremely fast. This significantly reduces the peak let-through current and thermal energy, providing enhanced protection for downstream circuits and equipment.
Does the CM3B500 feature an interchangeable trip unit?
Yes. The CM frame utilizes an interchangeable thermal-magnetic trip unit. This allows panel builders to swap the trip unit to a different amperage rating without replacing the entire breaker block.
Can the instantaneous trip response be adjusted on this model?
Yes. While the thermal long-time protection is fixed at 500 amps, the magnetic instantaneous trip is adjustable. This allows electricians to coordinate the breaker with specific inrush currents or downstream devices.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
We source obsolete and hard-to-find parts every day.
Shipping
Free Shipping Policy
Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.
Expedited Shipments
Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.
International Shipping
All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.