Eaton / Westinghouse MA3800 Molded Case Circuit Breaker
- 800A
- 3 Pole
- Bolt-On
Quantity
Eaton / Westinghouse MA3800 - 800A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Built to restore older electrical infrastructure, the Eaton MA3800 is a 3-pole, 800A molded case circuit breaker. It is designed for commercial and industrial environments requiring reliable protection. This bolt-on MCCB installs into legacy Westinghouse switchboards and Eaton Series C panelboards. It serves as an exact cross-reference for the MDL3800 and HMA3800, allowing facilities to maintain existing enclosures. The breaker features a 30kAIC rating at 480VAC and an interchangeable trip unit.Specifications
| Brand | Eaton / Westinghouse |
|---|---|
| Part Number | MA3800 |
| Series | MA |
| Amperage | 800A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 42kA @ 240VAC, 30kA @ 480VAC, 22kA @ 600VAC, 20kA @ 250VDC |
| Frame Type | MA |
|---|---|
| Terminal Type | Lugs |
| For Use With | Westinghouse Panelboards, Switchboards, Motor Control Centers, Eaton Series C Panelboards |
| Wire Gauge | (3) 3/0 AWG - 400 kcmil (Al/Cu) |
| Max Wire | 400 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
6 answersWhat modern breaker series replaces the obsolete Westinghouse MA3800?
Eaton replaced the legacy MA and M-Frame series with the Series C MDL line. For a modern 800A replacement, the MDL3800 or HMDL3800 is typically used. Keep in mind that retrofitting a newer frame into older panelboards may require different connector kits or mounting hardware.
Is there a high-interrupting capacity alternative to the standard MA3800?
Yes, the HMA3800 is the Mark 75 high-interrupting version of this breaker. It shares the same physical M-Frame footprint and 800A rating but provides enhanced fault protection, delivering up to 35kA at 480VAC compared to the 30kA rating of the standard MA3800.
What is the benefit of the adjustable magnetic trip on this breaker?
While the thermal overload protection is fixed, the adjustable magnetic function allows electricians to safely fine-tune the instantaneous trip threshold. This is critical for preventing nuisance tripping when starting large motors or transformers that draw temporary, high inrush currents.
Can the MA3800 be reverse-fed for backfeed applications?
Standard thermal-magnetic breakers without electronic trip units can generally be reverse-fed, provided there are no Line and Load markings stamped on the casing. Always verify the physical label on the breaker and consult the Authority Having Jurisdiction to ensure local code compliance for backfeed setups.
Which enclosures and switchboards are compatible with the MA3800?
As a legacy M-Frame breaker, it is primarily used in older Westinghouse distribution systems, including Pow-R-Line 4 panelboards, switchboards, and motor control centers. It is also suitable for Eaton Series C panelboards, mounting directly via its bolt-on connections.
What routine maintenance is recommended for older thermal-magnetic breakers?
Industrial molded case breakers require periodic inspection to ensure safe operation. Electricians should verify terminal torque, inspect the housing for thermal stress, and manually toggle the handle periodically. Mechanically exercising the breaker prevents internal lubricants from stiffening and ensures the trip mechanism remains responsive.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 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.