General defects associated with the Controller

Transformer noisy, dirty

• Causes

1. Excess sparking and chattering
2. Oil leakage – foreign make (unsuitable for tropical temperature)

Overheated parts

• Causes

1. Inverter cooling fan is dirty or dusty
2. Arc, spark, high resistance due to loose connection
3. Burned relay contacts due to Ageing, wear and tear of controller

(Schmelevator, 2016)

Burnt mark in controller cable