MC-40a Magnetic Contactor 40A for 18.5kW Motor Loads at 380/400V
The MC-40a is a three-pole magnetic contactor for switching three-phase motors and resistive loads in low voltage panels. A 220V AC coil suits the control circuits used on most 380/400V boards, and the 40A frame covers pumps, fans, compressors and conveyors up to 18.5kW.
Current Across Four Voltage Bands
AC-3 rated current is 40A at 220-240V and again at 380-400V, falling to 32A at 500-550V and 23A at 660-690V. Conventional thermal current is 60A, which leaves headroom for AC-1 loads such as heaters and lighting circuits.
Motor Size at 220V and 380V
The same frame is rated 11kW (15HP) at 220-240V, 18.5kW (25HP) at 380-400V and 22kW (30HP) at 500-690V. The kW curve rises with voltage while the ampere rating falls, so size the contactor from the motor nameplate first and check the ampere figure after that.
Coil and Auxiliary Wiring
The 220V AC coil works on 50Hz and 60Hz supplies. A 1NO+1NC auxiliary block is fitted as standard, rated 1.6A at 220-240V and 0.95A at 380-440V under AC-15 with 16A thermal current. Extra side blocks are available for panels that need more signal contacts.
Insulation, Life 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 mounts on DIN rail or screws straight to a plate. Send your motor rating, coil voltage and quantity to WTAIELE for a quote.
