Robinson Engineering, Inc.

Electrical Panel Quality Assurance Test

Panel Test Procedure

I think we can all agree that quality assurance is important. Without it, things probably wouldn’t be consistent in functionality and you’d always run the risk of getting a shoddy product.

Here at Robinson Engineering, we have in place a test procedure for all of the electrical control panels that we build, and I wanted to share the first portion of that plan so you catch a glimpse of the quality that goes into a panel built in our UL-508a listed panel shop.

Before the test begins, we:

1. Print a new copy of the finalized electrical drawing.

2. Ensure that someone other that the person who wired the panel is doing the testing.

3. Connect multi-panel systems if necessary.

When that’s all done, we move on to the test portion that takes place before connecting power to the panel. This is the stage we’ll discuss today.

First, all wiring and components are inspected for obvious non-conformities. If it looks good, we move on.

 Checking for Non-conformities on Electrical Panel

Next, all components are checked to ensure that they match the bill of materials. If lights are used, correct voltage is checked. If relays with surge suppressors are used, the correct type is confirmed. Also, all contacts on pushbuttons and switches are checked to make sure they’re the right ones.

Next, we check that the required component labels are present, correct, and easily visible.

 Component Label

Close behind that is the inspection of all wire labels to ensure that they are correct, facing outward, and are easily visible.

 Wire Lables Incorrect

Some of these are backward, so they have to be fixed before we can move on.

Wire Labels Correct

Ta da! Let’s move on.

After the component and wire labels are checked, we check all screw connections for tightness.

Screw Terminal Tightness

Then, we pull on each wire to ensure that no connections are loose and that wires have the appropriate amount of slack. You don’t want too much extra wire, but some is good to make sure that it’s not constantly under stress.

Wire Pull Test

After that, we use a multimeter to do a point-to-point continuity check on all wiring based on the electrical drawings and we highlight the drawing as each connection is verified.

 Continuity Test

Make sure any applicable jumpers are properly set and that there is an insulated barrier between exposed jumper ends and other jumpers. The barrier is really important so the jumpers don’t accidentally jump to each other and cause big problems.

 Terminal Jumpers

Using a multimeter, check across all normally open and normally closed contact for proper continuity and operation. This should include (if applicable) the operation of contactors, disconnects and switches.

Testing Open and Closed Contacts

Using a multimeter, check the disconnect handle for correct operation.

Testing the Disconnect

Using a multimeter, perform short circuit testing on all power circuits and PLC outputs.

Short Circuit TestingShort Circuit Testing PLC Outputs

Whew. And that’s just the beginning! All of this takes place before we even think about connecting power because we want to be sure that the panel is correct and safe to use to continue testing, and ultimately for our customers.

What other things do you do in your quality assurance tests? Is there anything you would add to ours? Let us know by leaving a comment or contacting our project manager Cliff at or 757-872-7292 ex 210.

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