MasterPact MTZ3 — 5000 A drawout breaker for main distribution
The Schneider Electric LV848356 is a MasterPact MTZ3 drawout circuit breaker rated 5000 A at 40 °C, 4-pole, with H2 performance class delivering 150 kA Ics at 415 V AC. It is designed for power distribution protection in main switchboards and industrial feeders where Category B selectivity is required — meaning it coordinates with downstream breakers to isolate only the faulted branch, keeping the rest of the plant online. The short-time withstand current (Icw) is 100 kA for up to 3 seconds, giving protection engineers headroom for selective coordination studies. Maximum breaking time is 25 ms, closing response within 80 ms.
At 690 V AC the Ics is 100 kA. Category B selectivity (per IEC 60947-2) means the breaker has a deliberate short-time delay, allowing downstream devices to clear first; this is essential for main-tie-main or feeder configurations where nuisance tripping of the entire plant is unacceptable. The Icw of 100 kA for 3 seconds gives the protection engineer a wide window to set time-current curves. Compare this to a standard Category A breaker that typically holds Icw for only 1 second — the MTZ3's 3-second rating simplifies coordination with downstream MCCBs and fuses.
Integration — drawout mounting, rear connection, panel dimensions
Drawout mounting means the breaker chassis stays wired in the switchboard while the removable portion can be racked out for maintenance or replacement without disturbing power connections. The breaker mounts on rails or a base plate. Both upside and downside connections are rear, which is typical for main switchboard feeders where busbars run behind the breaker. Overall dimensions with chassis: 403 mm depth, 1016 mm width, 479 mm height. Without chassis: 300 mm depth, 838 mm width, 300 mm height. IP30 protection is suitable for indoor switchboard installation; pollution degree 3 per IEC 60947-1 means the environment has conductive pollution (typical of industrial switchrooms).
Electrical durability: 6000 cycles under AC-3 duty (motor switching) at 440/690 V, and 1500 cycles under AC-23A (occasional switching of motors or other inductive loads). Mechanical durability is 10,000 cycles with periodic preventive maintenance. Power dissipation at rated current is 670 W — factor this into switchboard ventilation calculations. Neutral position is right. Sensor rating options span 2500 A to 5000 A, allowing the same frame to be used with lower-rated sensors for feeder applications.