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Eaton / Westinghouse MA3700 Molded Case Circuit Breaker
- 700A
- 3 Pole
- Bolt-On
Eaton / Westinghouse
MA3700
Molded Case Circuit Breaker
Brand
Eaton / Westinghouse
SKU
MA3700
Quantity
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Eaton / Westinghouse MA3700 - 700A 3 Pole Molded Case Circuit Breaker
Re-Certified
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Description
An exact replacement for older Westinghouse and Cutler-Hammer systems, the Eaton MA3700 restores power without requiring panel modifications. This 700A, 3-pole molded case circuit breaker is designed for commercial switchboards and motor control centers. Featuring a bolt-on mounting style, it serves as an exact match for aging infrastructure. It replaces original MA-frame units and is superseded by the MDL3700. It utilizes thermal-magnetic trip technology with an interchangeable trip unit.Specifications
| Brand | Eaton / Westinghouse |
|---|---|
| Part Number | MA3700-R |
| Series | MA |
| Amperage | 700A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 42kA @ 240VAC, 30kA @ 480VAC, 22kA @ 600VAC, 10kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Westinghouse Panelboards, Switchboards, Motor Control Centers, Eaton Series C Panelboards |
| Wire Gauge | (2) 500-750 kcmil (Al/Cu) or (3) 3/0 AWG - 400 kcmil (Al/Cu) |
| Max Wire | 750 kcmil |
| Min Wire | 3/0 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 |
|---|---|
| Accessories | Lugs |
| Standards | CSA C22.2 No. 5, NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Interchangeable Trip Unit |
Product FAQs
8 answersWhat enclosures and panelboards are compatible with the MA3700 circuit breaker?
The MA3700 is designed for use in legacy Westinghouse panelboards, switchboards, and motor control centers, as well as Eaton Series C panelboards.
What is the modern replacement for the obsolete Westinghouse MA3700?
The MA3700 has been superseded by the Eaton Series C MDL3700. However, using an exact MA3700 replacement allows you to restore power without requiring panel modifications or retrofit kits.
What wire sizes are accepted by the lugs on the MA3700?
The standard lugs accept either two 500 to 750 kcmil conductors or three 3/0 AWG to 400 kcmil conductors per phase. They are rated for both aluminum and copper wiring, making them suitable for a variety of heavy commercial and industrial feeds.
How does the adjustable magnetic trip function on the MA3700?
The MA3700 features a fixed thermal element for overload protection and an adjustable magnetic trip. This allows electricians to fine-tune the instantaneous short-circuit response to coordinate with downstream breakers and prevent nuisance tripping.
Does the MA3700 require a separate trip unit purchase?
No, this is provided as a complete unit. It includes the bolt-on M-Frame, the interchangeable thermal-magnetic trip unit, and the load-side lug terminals, so it is ready for installation.
Can I install internal accessories in the MA3700?
Yes, the MA frame supports field-installable internal accessories. Electricians can add components like shunt trips, auxiliary switches, undervoltage releases, and alarm switches to meet specific control requirements.
Can the MA3700 be used in direct current applications?
Yes, in addition to its standard AC ratings, the MA3700 is rated for 250VDC systems. It provides an interrupting capacity of 10kA at 250VDC, making it suitable for specific industrial DC applications.
Are the MA3700 and HMA3700 interchangeable?
Both breakers share the same physical M-Frame dimensions and bolt-on mounting. However, the HMA3700 has a higher interrupting capacity. You can upgrade to the HMA3700 if higher fault current ratings are required, but you cannot use the standard MA3700 if your system requires the higher HMA rating.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 1 review.
Total 5 star reviews: 1 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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1 review
- DHDave H.ReviewingSquare D MA36600 - 600A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/6/25Never had a problem
We like the service and the prices. The re-certified are great for projects that we have in house.