Electrical Contact Replacement: Answers to Common Questions

Below are common questions about electrical contact operation and choosing replacement contacts. Our goal is to help electrical distributors avoid supply chain delays when OEM delivery can be weeks or months away.

We’ve included links to the REPCO blog that goes into more detail about common problems and solutions for troubleshooting and maintaining control replacement parts.
 

Why has the manufacturer discontinued my electrical contact series?

Motor control systems and manufacturing equipment can be in service for years or decades. As each new device is designed it often requires a new size or shape for the electrical contacts. Manufacturers drive most changes in design during their development stage. This is one key reason an electrical control series is discontinued.
 
Another contributing factor to discontinued control lines is electrical industry mergers and acquisitions. The past few decades have seen the merger and acquisition of many leading OEM brands.
Overlapping lines often fall victim to cost cutting and streamlining efforts. So even if a series is popular, if the OEM is absorbed and the buyer has a competing line, the acquired series may be discontinued.

How can I safely check for worn electrical contacts?

If you’re checking a contactor connected to a power source, follow all safety precautions including:

-    Turn off power to the unit
-    Wear protective fire or flame resistant (FR) clothing
-    Check that your work environment is clean, stable and electrically safe
-    Do a visual check of the contacts to determine if they’re worn, burnt or contaminated by any environmental substances.
-    Push down on the movable contact holder to check the alignment as it mates with the stationary contacts.
-    Check the pads for pitting or other wear that could cause electrical arcing.
 
Watch this REPCO video on how to check for worn electrical contacts.
 
When Should I Replace Electrical Contacts? Silver padding on the electrical contact that is worn to more than one-half its original surface is an indicator that it’s time to plan to replace the contacts. It's possible to replace electrical contactor parts such as screws, coils and shunts as well as the movable and stationary contacts.
More on replacing electrical contacts.
 

What type of metal is used in electrical contacts?

Electrical contacts for motor controls are usually made from copper. Silver or silver-alloy pads are often brazed onto the copper base at the mating point to help resist sticking and welding of the movable and stationary contacts.
To combat contact welding, the silver is often blended with other metals creating highly conductive and wear-resistant alloys.
 

Can I Substitute Manufacturer Electrical Contacts?

As There’s no need for an electrical distributor to lose an order or place a backorder if the manufacturer does not have inventory. There's no performance difference with a REPCO equivalent.  All Repco products are guaranteed in fit, form and function. REPCO stocks replacements for all leading OEM brands.
 
Learn more about substituting OEM electrical contacts and check out Basics of electrical contact operation with illustrations.
 

How can I choose the right electrical contact Replacement?

A good place to start is the Repco electrical contact catalog.  Every photo in this catalog is actual size and can be used to help identify a contact. Get help selecting electrical contacts, carbon brush and control coils.

REPCO can help you keep customers and avoid delivery delays of OEM electric motor control parts.

Electrical Contacts, Motor Brushes and Motor Control Coils when you need them.  Need Help? 800.787.0111