Reviews of ICM491 Single-Phase Line Voltage Monitor NEW

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I have no way of recording how many times this circuit has activated but since installing it there have been numerous power interruptions(10-20 maybe more). Salt accumulating on powerline insulators and such are being blamed for this activity due to the severe drought along the coastal areas of Texas.

I guess I got a jump on the situation by recognizing that my new higher efficient A/C wasn't delaying after these glitches earlier in the season. I think the thermostat is supposed to delay a restart after a dropout but evidently is not fast enough. Also there could be some erratic or undetermined interruptions. The ICM491 kills the relay @ .05+ sec. I think that is faster than two complete cycles. My older A/C had a circuit for this and it lasted 32+ years without losing a compressor. I needed a delay ckt. that was powered by the feeding 240v. I had to do some searching to find this unit and finally found it described ,I think at ICM's site. Found the best price at Amazon and soon had it in my hands.

All I needed to install it in about an hour was four female 1/4in. quick disconnect terminal connectors because the unit had only male 1/4in. spade connectors, 4 different colored 12in. wires, a small twist on connector and a roll of black electrical tape to wrap all twistons to secure them and protect from the enviornment.

To install I waited till A/C finished its cycle and turned the thermostat off-then killed the ckt. breaker in main box and at outside condenser unit. Checked to make sure voltages were off and hooked up the wires marked for 240v of the ICM941 one each to the red and black feed wires from ckt. breaker (polarity didn't matter). Broke one of the twiston connectors from the thermostat, connected one wire from the ICM941 n/c (normally closed) terminal and the other wire from ICM941 n/c(normally closed) terminal to the other wire that was separated by the break. Set the voltage for 120/240 and the delay time to 2min. Turned thermostat on and main ckt. breaker handed my timer stopwatch and energized the local sw/ckt breaker and timer. Got 2mins. 17sec. delay before compressor started. Reasoning for using normally closed contacts on the ICM941 is that is the position provided when the unit is energized. When voltage drops out .05sec. this ckt is opened and will not close to start the compressor again until 2-3mins. appx. (compressor unload time).

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This is the 2nd one I have bought the 1st from amazon. I have it installed on my A/C compressor to protect from power surges. It has saved my compressor 2 times that I know of. Previously I had lost 4 compressors to power surges.