How do you know when it’s time to replace electrical contacts?

The obvious sign is when your machinery stops working and you narrow it down to a failed electrical contact. But this is past the point when routine maintenance would have discovered an electrical contact was wearing down, so it’s unusual.

When contacts begin to “stick”

The first indication that electrical contacts are nearing replacement time is when they begin to stick during operation. This is primarily so with copper-only DC contacts.  Most manufacturers recommend that when the silver pad is one-half worn on AC contacts and on some silver-tipped DC ones, that the contacts be replaced.  

Electrical contacts withstand regular abuse from electric arcing - even when it’s just a small jump. Even the largest contacts wear out after prolonged exposure. The contactor tips begin to melt allowing the underlying metals to “melt together” due to arcing or from extended use and the resulting high temperatures. This causes the metals of the stationary and movable contacts to fuse slightly - or as it’s called, “to stick.”

Other contactor parts wear out too

Electrical contacts can suffer the failure of any part of its assembly. The control coil spring gradually loses its “tension” and needs replacing. Screws, auxiliaries, arcs, levers, and shunts may wear or fail. While the duty cycle of most electrical contacts is rather long, regular inspection and maintenance is still required.

Many contactor parts can be replaced

There are many items on a contactor that can be replaced. Springs are generally routine maintenance. But even contact pads can be replaced on occasion via re-tipping. However, in some situations, it’s generally simpler and best to replace the entire contact kit to prevent future problems, unless the replacement is no longer available.

Repco stocks hundreds of OEM compatible contacts

When it’s time to replace electrical contacts you can choose to use the OEM electrical contact or you can be a smart shopper and select an OEM compatible product. Repco stocks hundreds of existing and discontinued contact kits for most major control manufacturers. Repco replacement electrical contacts are available through hundreds of electrical distributors throughout the US.