Mody Pumps NC 06360_08360_10360-M - Manual (Page 6)

BUILT-IN CONTROLS
THE BUILT-IN MOTOR PROTECTION OF THE PUMP AUTOMATICALLY BREAKS THE CURRENT IF
THE MOTOR IS OVERHEATED. WHEN THE CURRENT IS CUT OFF, IT IS NECESSARY TO FIND
THE CAUSE AND TAKE REMEDIAL ACTION.
OVERLOAD/OVERHEAT PROTECTION (REFER CIRCUIT DIAGRAM ABOVE)
THE CONTACTOR COIL IS COUPLED IN SERIES WITH THE BI-METALLIC SWITCHES. THE COIL
CIRCUIT IS CONNECTED BETWEEN TWO OF THE INCOMING PHASE WIRES. WHEN THE PUMP IS
CONNECTED TO THE POWER MAINS, THE COIL GETS VOLTAGE AND ATTRACTS THE CONTACT
BRIDGE. THE MOTOR STARTS AND THE PUMP BEGINS TO OPERATE. IF THE MOTOR GETS
OVERHEATED THE BI-METALLIC SWITCHES OPEN AND CUT OFF THE CURRENT TO THE COIL.
WHEN THE MOTOR HAS COOLED DOWN TO NORMAL OPERATING TEMPERATURE THE SWITCHES
CLOSE, THE CONTACTOR COIL IS AGAIN ENERGIZED AND THE PUMP RE-STARTS. IT IS
ADVISABLE TO FIND OUT THE CAUSE OF OVERHEATING IF THE PUMP TRIPS OFTEN.