MC-50a Magnetic Contactor 50A for 22kW Motors at 380/400V
The MC-50a is a three-pole magnetic contactor for motors and resistive loads in low voltage distribution panels. On a 380/400V bus it switches 50A of AC-3 load, the typical size for a 22kW pump, fan or compressor circuit, with a 70A thermal frame behind it and a 220V AC coil for the control circuit.
Current and Thermal Headroom
AC-3 current is 55A at 220-240V, 50A at 380-400V, 43A at 500-550V and 28A at 660-690V. Conventional thermal current is 70A, which keeps the frame inside its rating when the contactor feeds AC-1 loads such as resistive heaters or a lighting distribution circuit.
Matching a 22kW Motor
Motor rating is 15kW (20HP) at 220-240V, 22kW (30HP) at 380-400V and 30kW (40HP) at 500-550V and 660-690V. Check the motor nameplate kW first, then the supply voltage at the panel, because the same contactor covers 22kW at 380V and 30kW at 500V with different current on each band.
Auxiliary Contacts for Control Circuits
One NO and one NC auxiliary contact is fitted as standard, rated 1.6A at 220-240V and 0.95A at 380-440V under AC-15 with 16A thermal current. A hold-in contact, a run lamp or a feedback wire to the controller can be taken straight from this block. Further side blocks are available if the circuit needs a second pair.
Insulation, Terminals and Fixing
Rated insulation voltage is 690V and mechanical life reaches 10 million operations. Main terminals are marked R/1/L1, S/3/L2 and T/5/L3 on the line side and U/2/T1, V/4/T2 and W/6/T3 on the load side, and the body fixes to DIN rail or screws to a mounting plate. Send your motor kW, control voltage and quantity to WTAIELE for a quote.
