Thermally Protected Motor Wiring

The degree of protection that an internal protection device provides is classified in the iec 60034 11 standard.

Thermally protected motor wiring.

The type of thermal overload for which the thermal protection is designed 1 digit. Electric motor thermal overload switch location. On a 12 wire motor wired for high voltage i e 480v 10t 11t and 12t must be connected together but not connected to anything else. The thermal protection is present to turn the motor off when excessive heat is generated within the motor circuitry.

For understanding motor thermal overload protection in induction motor we can discuss the operating principle of three phase induction motor. Due to such symmetrical distribution when three phase power supply. The 64 watts lost 400 336 64w becomes heat. An 84 efficient motor with a total watt draw of 400w produces 336 watts of useful energy 400 x 84 336w.

A motor s efficiency is a measurement of useful work produced by the motor versus the energy that it consumes heat and friction. Tp is the abbreviation for thermal protection. Thermistor is a small non linear resistance sensors which can be embedded within the insulation of a motor winding to provide a close thermal association with the winding it s made from a metal oxide or semiconductor material. The other 9 wires would be connected as in a 9 wire motor note in a 9 wire motor the equivalent of t10 t11 and t12 are internally connected together.

This safety feature halts the temperature climb before it can burn up the motor. There is one cylindrical stator and a three phase winding is symmetrically distributed in the inner periphery of the stator. L1 to t1 l2 to t2 l3 to t3 t4 to t7 t5 to t8 and t6. Motors are to be returned to a hazardous and or explosive atmosphere.

The thermal protector consists of one or more heat sensing elements built into the motor or motor compressor plus an external control device. Electric motor thermal overload switch location. This series offers several different horsepower options as well as thermal protection. Single phase wiring diagrams always use wiring diagram supplied on motor nameplate for motors without thermal protection single voltage single rotation single voltage reversible rotation dual voltage single rotation split phase motor.

Always use wiring diagram supplied on motor nameplate. Different types of thermal protection exist and are identified by a tp code tpxxx which indicates. The 5kh series comes with permanently lubricated bearings.