Compressor Defender™ by Intermatic?

To prevent future surge damage, I had an electrician install a whole-house surge protector at the main electrical panel.

Sponsored by Intermatic®

In 2015, lightning struck a tree in my daughter’s neighborhood. The surge damaged several electronic devices. The cost to replace the Internet modem, TV and home theater receiver totaled slightly less than her $1,000 homeowner’s insurance deductible, so she had to bear the entire cost.

To prevent future surge damage, I had an electrician install a whole-house surge protector at the main electrical panel. Then I installed plug-in and hardwired surge protector receptacles at each of her electronic devices and appliances. But I was stumped as to how to protect her home’s central air conditioning (A/C) unit.

I was especially concerned about her A/C because her neighborhood sometimes experienced rapid power failures, where the lights would flicker for a fraction of a second. I know that kind of rapid Off/On cycling can be really hard on the A/C’s compressor, causing it to restart against high pressures. That strain can overheat and damage the compressor motor windings.

I found a few surge and short-cycle protection devices on the Internet. But the installations seemed complicated. They required swapping out the existing relay and mounting additional components inside the tight space inside the condensing unit. Then I found the Compressor Defender™ product from Intermatic®. It’s a surge and short-cycle protection device that also includes brownout protection (when voltage drops too low during peak electrical usage in the neighborhood). The short-cycle feature senses power flickers and “times out” the compressor long enough to allow system pressures to equalize before restarting. The brownout feature works the same way, shutting off both the compressor and the condenser fan when it detects voltage that’s too low for safe operation, then restarting the motors when proper voltage returns.

The best part is that the Compressor Defender™ costs about $80 (Intermatic #CD1-024RK at Plus, it’s much easier to install than the other products I found. Just mount it to the disconnect box on the house and splice in two wires inside the condensing unit.

Three wires, 30 minutes, and it’s done

I turned off the A/C’s circuit breaker and flipped off the power switch at the furnace. Then I opened the cover on the outside disconnect box, removed the inner cover and double-checked that the power was off using a voltage sniffer. It was off, and I was good to go.

Next, I removed a knockout on the side of the disconnect box, fed in the wires from the Compressor Defender™, and secured it with the locknut.

Compressor Defender™ by Intermatic®

Then I routed each of the two black wires up to the screw terminals marked ‘LINE.’

Compressor Defender™ by Intermatic®

I cut the wires to length, stripped the insulation, inserted them under the screw clamps and tightened them. I secured the white wire from the Compressor Defender™ to the grounding/bonding bus. That was it for the disconnect box, so I put the covers back on.

Using zip ties, I secured the low-voltage cable to the conduit running from the Compressor Defender™ to the A/C condensing unit.

Compressor Defender™ by Intermatic®

Then I removed the condenser unit’s access cover and spliced the low-voltage cable from the Compressor Defender™ in series with one of the A/C control wires coming from the house. I reinstalled the access cover and turned on the power.

Compressor Defender™ by Intermatic®

The green light lit up on the Compressor Defender™ and the AC fired up when I lowered the temperature at the thermostat. The entire Compressor Defender™ installation took less than 30 minutes.

Now all her electronics are protected against power surges, and her expensive A/C system is protected against the three most common electrical risks.

For more information on the Compressor Defender™ product, visit the Intermatic website.

— Rick Muscoplat, Contributing Editor

This is a sponsored conversation written by me on behalf of Intermatic. The opinions and text are all mine.

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