Aging is accelerated when operational condition environment stress etc. is more than normal
operational condition. Endurance decrease of coil or main cause of burnout are shown
below.
• Insertion fault
Coil is burned out by excitation rush current (10~15 times of holding current) flowing into the coil,
if you opperate it continuously without perfect inhalation after the power voltage decrease abnormal material penetrates
into magnetic contact pole.
• Overcurrent
Excitation current increases when permitted voltage is too high for coil and, the coil endurance is reduced. In case of high
current,coil will sometimes burn out.
• Application mistake of voltage and frequency
It can be cause of coil burnout when coil rated voltage is higher or lower than the power voltage.
Coil is burnt out when frequency application is wrong in case of coil which has middle tap of terminal three or terminal four.
• Excessive switching frequency
It can be the cause of burnout when it is used more than designated on/off frequency.
• Closing installation
Heating emmitance installation is accellerated for heating aging by the central coil is the highest temperature when magnetic
switch is used at continuous flow current.
• Chattering
If contact point has severe chattering by control voltage variation or coil terminal release, it causes coil burnout by drive current flowing into the coil.