The LV839004 is a Masterpact MTZ3 50 HA non-automatic switch disconnector from Schneider Electric, rated for 5000 A at 104 °F (40 °C) in a 4-pole drawout chassis mount. This is a distribution-class device built to ANSI C37.50 standards, carrying a 65 kA Icu breaking capacity at 254 V, 508 V, and 635 V AC 50/60 Hz when used with an external relay. The short-time withstand current [Icw] is 85 kA for 0.5 s per ANSI C37.50, which gives the coordination engineer headroom for selective tripping downstream.
Sizing and deployment context
At 5000 A continuous, this switch sits at the main or feeder level in a low-voltage distribution switchboard. The drawout mounting means it pulls out for inspection or replacement without de-energizing the bus — a feature the maintenance planner will appreciate for line-up downtime. The 4-pole configuration covers three-phase plus neutral, common for North American 277/480 V wye or 347/600 V wye services.
The 65 kA Icu rating holds across the full voltage range (254 V through 635 V AC) with an external relay per ANSI C37.50. That flat curve is unusual — most breakers derate as voltage rises. For the site electrical engineer, this means the same SCCR applies whether the service is 480 V or 600 V, simplifying the coordination study. The 85 kA Icw for 0.5 s lets downstream breakers clear a fault before this device trips, keeping selective coordination intact.
Physical integration
The chassis-mounted drawout cassette measures 40.5 in (1028.7 mm) wide, 18.8 in (478.1 mm) high, and 16.8 in (426.8 mm) deep. Connection pitch is 9.06 in (230 mm). The panel OEM needs to verify the cutout and gland plate dimensions against the switchboard layout — these are large-frame dimensions for a 5000 A device. Push-button control is integral to the front escutcheon.