The Square D PowerPact LJA36600U44XYH2 is a high-quality circuit breaker with a maximum amperage of 600A. This product, along with the S432575 external neutral transformer, is designed for use in electrical systems requiring reliable and efficient power distribution. As a trusted brand in the industry, Square D ensures that this circuit breaker is built to last and provide reliable performance for industrial and commercial applications.
LJA
• LJ frame molded-case circuit breaker
• A = AC rated
• Industrial / heavy-duty series (older but very common)
3
• 3-pole breaker
6600
• 600 amp continuous rating
• LJ frame maxed out (big boy breaker)
U
• Thermal-magnetic trip unit
• Fixed trip (not electronic)
44
• Interrupting rating code
• Typically 42–65 kA @ 480 VAC (exact value depends on CAT spec sheet, but this is a high-interrupt industrial rating)
X
• Special accessory or factory modification
• Often shunt trip / auxiliary contacts / special terminals (varies by order)
Y
• Additional factory option
• Could be alarm switch, modified lugs, or custom calibration
H2
• Internal revision / design version
• Not usually relevant for field replacement unless matching exact vintage