As an electrician, you’re likely pretty familiar with receptacle installation. How familiar are you with receptacle tension testing, though? While some electricians deal with it often, others can go years without ever having to tension test receptacles. It’s possible that you’ve never had to do any receptacle tension testing at all.
If you’re not that familiar with tension testing, most likely it’s because you have few if any clients that require it. It won’t hurt to learn more about the process and how important it is in some industries, though, because you never know what needs your next client is going to have.
What Is Tension Testing?
One of the big concerns in some industries is that overloaded equipment can cause hazards due to insufficient grounding at the receptacle. One way to prevent this is to make sure that there’s sufficient contact between the receptacle and the ground pin of plugs. If the ground pin doesn’t make a strong enough contact, it won’t take much to shift the plug and weaken the grounding connection of the entire device.
This is where tension testing (which is sometimes called retention testing) comes in. The test is essentially a test of the grip strength of the receptacle, in regard to how well it holds on to the grounding pin of a plug. If the tension strength of the receptacle falls below certain parameters, it fails the test and needs to be replaced.
Why Tension Test?
The big reason for tension testing is because it helps to preserve the equipment that’s plugged into a receptacle. Hospitals and other organizations that use expensive or critical equipment are the biggest users of tension testing. Equipment is often plugged in and unplugged multiple times during the day, and a short or other problem at the receptacle could cause serious issues in equipment that may cost tens of thousands of dollars (or more) to replace.
Because of this, tension testing is often performed on a regular basis to ensure that all receptacles have sufficient tension to keep the ground pin secure within the receptacle during operation. While some of this testing is done by on-site maintenance workers, an electrician may be brought in when the client is ready to perform a test-and-replace check across the entire building or campus.
How to Test
Even if you’ve never done tension testing, it’s actually not difficult. Receptacle tension testers are small handheld units similar to other receptacle testers and are small enough to fit in a toolbox. Two prongs on the tester are plugged into an outlet just like you would any plug. A small rod on the other end of the tester allows you to pull on the unit, with dials or indicators showing how much pressure is being applied both on your end and on both of the plugs. This information lets you know how much pressure the receptacle can withstand and also shows you how much tension the outlet exerts to hold onto the prongs when the test finally fails.
Most of the time, if a client asks for tension testing it’s because they have a legitimate need for it. It may be tempting to perform other tests and call it “good enough”, but if your client knows enough about its needs to know that tension testing is important then you’ll be doing a great disservice by not doing what they asked for. Do the tests, do them properly and replace any receptacles that don’t pass with flying colors.
Learning how to do receptacle tension testing is just another skill that you can add to your skillset, and it’s unlikely that you’ll wear out your testing equipment anytime soon, so it will most likely be just a one-time purchase. You may not ever have a need for it, but if you do then your clients can rest assured that you know what you’re doing and can deliver exactly what they ask for. Who knows… you may even get to clock a few more man-hours replacing what fails the test.