We 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 KNBC TECHNOLOGIES PVT LTD, 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 work shop.
First, all wiring and components are inspected for obvious non-conformities. If it looks good, we move on.
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.
Close behind that is the inspection of all wire labels to ensure that they are correct, facing outward, and are easily visible.
Some of these are backward, so they have to be fixed before we can move on.
After the component and wire labels are checked, we check all screw connections for 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.
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.
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.
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.
Using a multimeter, check the disconnect handle for correct operation.
Using a multimeter, perform short circuit testing on all power circuits and 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.