Providing robust thermal-magnetic protection, the Square D MAL365001212 is a 500A, 3-pole molded case circuit breaker. It features an adjustable magnetic trip and comes equipped with a factory-installed 1A/1B auxiliary switch, denoted by the 1212 catalog suffix. This M-Frame MCCB is engineered for unit mounting in Square D switchboards, enclosures, and motor control centers. It delivers a 30kAIC interrupting rating at 480VAC. The modern equivalent is the MGL36500 with an added aux switch.
Square D Switchboards, Motor Control Centers, Enclosures
Wire Gauge
(3) 3/0 AWG - 500 kcmil (Al/Cu)
Max Wire
500 kcmil
Min Wire
3/0 AWG
Protection and operation
Trip Technology
Thermal Magnetic
Trip Function Code
LI
Trip Function
Long-Time, Instantaneous
Trip Adjustability
Fixed Thermal, Adjustable Magnetic
Standards and features
Available Options
Shunt Trip, Undervoltage Release, Alarm Switch
Accessories
Line and Load Lugs Included, Auxiliary Switch (Factory Installed)
Standards
CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489
Approval
CSA, UL
Temp Rating
40C
Construction Features
HACR Rated, Non-Interchangeable Trip
Product FAQs
7 answers
What equipment is the MAL365001212 designed to be installed in?
This unit-mount breaker is compatible with Square D switchboards, motor control centers, and standalone enclosures.
What wire sizes are supported by the terminals on this 500A breaker?
The factory lugs accommodate three 3/0 AWG to 500 kcmil conductors per phase. The terminals are rated for both aluminum and copper wire.
What does the 1212 suffix indicate on the MAL365001212 catalog number?
The 1212 suffix designates a factory-installed auxiliary switch. This provides 1A/1B (one normally open and one normally closed) contacts for remote status signaling.
How does the trip unit function on the MAL365001212?
This legacy M-frame breaker uses a thermal-magnetic trip unit. It provides fixed thermal protection for long-time overloads and an adjustable magnetic trip for instantaneous short-circuit protection.
Is this Square D M-frame breaker rated for direct current (DC) systems?
Yes, in addition to its AC ratings, this breaker is certified for use in DC systems up to 250VDC, delivering a 14kA interrupting rating.
Does this breaker mount onto an I-Line bussing system?
No, the MAL365001212 is a unit-mount, feed-thru circuit breaker. It requires bolted wire connections for both the line and load sides and cannot be plugged into an I-Line panelboard.
Is the MAL365001212 a current production PowerPact breaker?
No, the MAL frame is a legacy molded case circuit breaker from Square D. It predates the modern PowerPact M-frame series but remains available for replacing existing units in older switchboards and motor control centers.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 5 reviews.