How to assess or improve premature failure of contactors

Are your contactors failing Prematurely?

What could be the cause?

It is firstly important to be sure you know the peak and nominal load currents in order to select the correct contactor for any given application. For highly inductive loads this may be difficult. Try using a peak hold Current clamp such as M266 available in our online store. 

1) The arcing at first contact is due to inductive load and may not be able to be avoided in such applications.

2) Thermal relays may help to prevent the thermal overload on the contactors. Note: thermal overloads will give a relay trip to allow the machine to be paused while the contactor cools down. Would this be acceptable for you? or will it damage/waste product?

3) From both the factory and one of our most trusted Electricians, the best way forward to to oversize the contactors. 

Also the contactor should not be mounted horizontally. If any dust or dirt settles in the contacts then the life will be reduced as there will not be a "clean" contact. In addition, the contactor Coils is designed to operate while being mounted vertically. Firstly, the additional force of gravity make the contactor less efficient and Second, the could fail prematurely to to the coil being repeatedly overloaded. 

Our recommendations if you wish to eliminate the issue and improve reliability:

-Increase the size of the contactor

-Mount contactor in upright Position only (DIN Rail or Panel Mounted)

-Mount contactor in a sealed enclosure to avoid dust settling. Ideally not mounted on vibrating machinery.

- (Optionally) mount thermal overload relays set to maximum (25 Amp). (make sure the application is suitable for thermal overload shutdown. Ie. potential for wasted product.

For any questions, feel free to contact our friendly team at Fastron Electronics