Replacing the various electrical components used on heating, air conditioning, and refrigeration systems is a common task for technicians. Many times, especially when working with electronic controllers, multiple sets of wires will be leading to and from these components. When replacing these components, it is easy to cross some of this wiring. This will surely lead to problems for a technician.

When this occurs, the best-case scenario is that the installed component will not operate correctly and a technician will simply need to rewire the component. The worst-case scenario is that the installed component or another component in the system becomes damaged as a result of the miswiring. The technician will not only need to rewire the component, but also replace the damaged component at no charge to the customer.

There is a simple way to prevent this scenario from occurring. Any time you need to replace an electrical component, simply draw a picture of the wiring connected to the component. Draw the picture so each of the individual wires are identified and shown exactly how they are landed on the component. This will help prevent any miswiring of the component.

This also is a tremendous aid when the component is not going to be immediately replaced. If the technician needs to remove the component and bring it back to the shop or wholesaler to find a suitable replacement, drawing a picture of the wiring is even more beneficial.

If the same colored wiring is used at the component, the wires will need to be physically labeled so they can be correctly identified on the picture. Wire labels or colored electrical tape are simple and easy ways of identifying multiple sets of wiring of the same color.

Before you remove any wiring from an electrical component, always make sure the voltage source to the circuit has been disconnected. Some systems may have two voltage sources, one for the motor circuit and another for the control circuit. Also, always test the circuit and verify with your own voltmeter that all the voltage has been truly disconnected. It is possible for the disconnect switch to be defective or partially bypassed, leaving voltage still applied to the circuit even though the switch appears to be in its off position.

Also, examine the wiring before removing the component and look for hardened or brittle sections. If discovered, this wiring should be replaced. Be sure to use the same style wiring when replacing any damaged wires. For example, if 14-gauge stranded wire is used, replace it with 14-gauge stranded wire.

If done correctly, the installation of even the most complicated controls can be simple, and costly mistakes can be prevented. Remember: Spending a little extra time to do a job right the first time is always beneficial to both the technician and the customer.

Publication date: 03/31/2008