The Coils are bobbin wound with copper wire for various application like Hydraulic/Pneumatic direction control valves, contactor coils for circuit breakers etc.
Automatic coil winding machines are used to achieve consistent quality of winding and high precision wire tensioners for maintaining the requisite wire elongation. Specific to application the coils are encapsulated or impregnated.
The coil assemblies undergo stringent test procedures where in the product is tested for turns, resistance measurement, surge comparison, HV tests. For hydraulic applications the pole tubes are manufactured on high precision CNC machines and evaluated for leak tests.
Every coil with spool is additionally tested for force, V/S measurement and hydraulic with stand pressure test. Endurance tests are also carried out by simulating actual operating conditions to ascertain the product functionality.