Designed for heavy-duty applications, the Square D MHL36900 is a 3-pole, 900A molded case circuit breaker. It is part of the legacy M-frame series, offering dependable LI trip functions. This unit-mount breaker fits into Square D switchboards and motor control centers. It is replaced by the PJL36100U44A, which requires adjusting the trip unit to 900A. Featuring a 65kAIC rating at 480VAC, it utilizes a non-interchangeable trip design. AL900MA lugs are included for secure terminations.
High Interrupting Capacity, HACR Rated, Non-Interchangeable Trip
Product FAQs
8 answers
Is the MHL36900 still manufactured by Square D?
The MHL36900 is a legacy M-frame breaker and is no longer in active production. It has been superseded by the modern PowerPact P-frame series.
What is the modern replacement for the MHL36900?
The modern replacement is the PowerPact P-frame, specifically catalog number PJL36100U44A. Because the P-frame uses an electronic trip unit, the trip settings must be adjusted to match the 900A rating of the original MHL36900.
What equipment is this breaker designed to fit?
This unit-mount M-frame breaker is designed for installation in Square D switchboards and motor control centers that accommodate legacy M-frame dimensions.
What lug kit is standard for this 900A breaker?
The standard lug kit for the MHL36900 is the AL900MA. This kit accepts three 3/0 AWG to 500 kcmil aluminum or copper wires per phase.
How does the adjustable magnetic trip function work on this model?
While the thermal overload protection is fixed at 900A, the adjustable magnetic trip allows you to tune the instantaneous short-circuit response threshold. This helps coordinate with downstream breakers to prevent nuisance tripping.
Can I mount this breaker in an I-Line panelboard?
No. The MHL36900 is a unit-mount, feed-thru breaker designed for lug-to-lug or bolt-on connections. It lacks the plug-on jaw construction required for Square D I-Line distribution panels.
Is this breaker suitable for DC applications?
Yes, the MHL36900 is rated for up to 250VDC with an interrupting capacity of 14kA. This makes it suitable for specific industrial DC control and distribution circuits.
Does this breaker feature a push-to-trip mechanism?
Yes, Square D M-frame breakers include a mechanical push-to-trip button on the front cover. This allows you to manually exercise the tripping mechanism for routine maintenance and safety verification.
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