Anyone use out door surge suppressor for HVAC unit?

[alarmguy]

I added one of these to the panel in March. Our furnace control board died and was replaced under warranty. The tech mentioned that it would be a good idea to have one as, in his words, " all those EV chargers in people's houses are causing spikes". I doubt that is the problem, but added one for other possible spikes.

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Now thinking maybe another one on the AC unit would be helpful as well.

An external one would be by first choice such as you installed I just didn’t want to get into a project of cutting the drywall so I went with the internal

Ironically, for me, adding the second one at the HVAC unit is very cost-effective for $65 and a few minutes to wire into the outside HCAC disconnect. What is more is that the AC breaker is right next to the main and the wiring from the circuit breaker panel to the outside AC unit is maybe 3 feet long because the unit sits right on the outside wall of the breaker panel if that makes any sense I was thinking maybe it might help quell an overwhelming surge, but whatever, I think too much

Amazon says they will both be here on Sunday. Not sure if I’ll be able to get it in that day.

 

[Kantaro]

I added one of these to the panel in March. Our furnace control board died and was replaced under warranty. The tech mentioned that it would be a good idea to have one as, in his words, " all those EV chargers in people's houses are causing spikes". I doubt that is the problem, but added one for other possible spikes.

View attachment 226904
Now thinking maybe another one on the AC unit would be helpful as well.

A whole home SPD is never a bad idea, especially when every little thing seems to have a circuit board now. Consider it cheap insurance

 

[alarmguy]

Just came in the mail this afternoon and I installed it. Easy stuff but the darn knock out on the box knocked out the size I wanted and one size larger so I have to pick up two conduit reducing washers in Home Depot I guess, so it fits perfectly secure. Annoying I just could not prevent the larger knockout to come out without the smaller and I was careful.
Anyway, all good, its connected, then will have to do it all again when I get the washers.
Its a weighty robust feeling thing, surprised me, looks like two ceramic boxes inside the housing.

I also bought a basic whole panel surge (below) that takes up two slots in the main breaker panel. Still have to install that and turn off power move one side of breakers around

 

[Nukeman7]

Just came in the mail this afternoon and I installed it. Easy stuff but the darn knock out on the box knocked out the size I wanted and one size larger so I have to pick up two conduit reducing washers in Home Depot I guess, so it fits perfectly secure. Annoying I just could not prevent the larger knockout to come out without the smaller and I was careful.
Anyway, all good, its connected, then will have to do it all again when I get the washers.
Its a weighty robust feeling thing, surprised me, looks like two ceramic boxes inside the housing.

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Can you post a close up photo of how the wires connect to the terminals inside the A/C disconnect box? I believe the AG3000 surge suppressor unit has two black wires and one white wire. I have one on the way and want to ensure it is connected correctly when it arrives tomorrow.

 

[alarmguy]

Can you post a close up photo of how the wires connect to the terminals inside the A/C disconnect box? I believe the AG3000 surge suppressor unit has two black wires and one white wire. I have one on the way and want to ensure it is connected correctly when it arrives tomorrow.

Yes, I just want to say if you are unsure of yourself get an electrician, hard to comment except for my own system.
Very clear diagram comes with the suppressor.

You have two line voltage and one neutral. I connected the two line (black) to the two line coming from the house in the illustration and the neutral (white) to the ground bar.

My only issue was the knock out on the side in which the larger 3/4 inch came out with the 1/2 inch, No problem, went to Home Depot and got a conduit reducer. to reduce the 3/4 back to 1/2.

Took more than a few shots so you could see slightly different angles. The two extreme left and right wires on the buss are going down to the outside unit. (load) along with the center green/ground. The two coming in from the back with the copper ground wire are coming from the house breaker panel. Of course the White and Two Black going out the side is the Surge Suppressor. Also notice the gentle loops I made with the surge wires, Ive read many places sharp bends are no good for surge suppressors and 4 inch loop or gentle loop is ideal

 

[Nukeman7]

Thanks for the excellent photos and the schematic. Looks like a piece of cake: Black wires to line from main breaker box and white wire to neutral/ground buss terminal. I'll be extra careful with removing the knockout since my box is plastic.

Final question: Did you shoot those photos with your iPhone?

 

[alarmguy]

Thanks for the excellent photos and the schematic. Looks like a piece of cake: Black wires to line from main breaker box and white wire to neutral/ground buss terminal. I'll be extra careful with removing the knockout since my box is plastic.

Final question: Did you shoot those photos with your iPhone?

Sure thing, Im big on surge devices, never had one on my AC UNITS in the last house. At the time my neighbor had his two units replaced and then became aware of them. You are correct, piece of cake and satisfying for me.

Yes, I took the photos with my iPhone 13. Actually any photo I post in here is from that phone.

 

[dcd]

I had the installer put surge protection on the outside and inside units when I had a Trane inverter heat pump installed a couple of years ago.

This is what they used. Appears to be about $69 on Amazon now. I think it was cheaper at the time.

 

[Kantaro]

Yes, I just want to say if you are unsure of yourself get an electrician, hard to comment except for my own system.
Very clear diagram comes with the suppressor.

You have two line voltage and one neutral. I connected the two line (black) to the two line coming from the house in the illustration and the neutral (white) to the ground bar.

My only issue was the knock out on the side in which the larger 3/4 inch came out with the 1/2 inch, No problem, went to Home Depot and got a conduit reducer. to reduce the 3/4 back to 1/2.

Took more than a few shots so you could see slightly different angles. The two extreme left and right wires on the buss are going down to the outside unit. (load) along with the center green/ground. The two coming in from the back with the copper ground wire are coming from the house breaker panel. Of course the White and Two Black going out the side is the Surge Suppressor. Also notice the gentle loops I made with the surge wires, Ive read many places sharp bends are no good for surge suppressors and 4 inch loop or gentle loop is ideal

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Ideally they should be pigtailed instead of double tapped lugs, especially if the disconnect lugs are only rated for one wire. You can use the excess wire from the SPD for the pigtails

 

[alarmguy]

Ideally they should be pigtailed instead of double tapped lugs, especially if the disconnect lugs are only rated for one wire. You can use the excess wire from the SPD for the pigtails

Good point, I was bothered by which way to go and not sure of an “accepted” solution.
The reason being Im pretty sure you can’t pigtail connections in a breaker box or double tap. Yet this is a connection box so not sure what applies.

Since a surge is not a current drawing device I chose to double tap in order to maintain the integrity of the high current connections to the buss/disconnect and compressor. But then again maybe that is the idea of pigtailing.
How much sense that makes I will now have to look it up but almost certain of … ?

Edit:
I found two videos quickly and can see both methods used but the first video seems to be the correct way as you mention.
I only briefly found these and going back to sleep now LOL

Being the SPD is labeled as 10 gauge I may go back one day and do as you suggest. I would like some confirmation from an electrician or read up online but you make perfect sense.
Great post, thanks for your reply/input.







It’s amazing the disparity in the way these things are hooked up by AC technicians.
I do think because ant one time depending on the state some SPDs could be hooked up in different ways.
After looking more I agree with your post as I mentioned.
Here is another AC guy doing the same thing yet the first video aligns with the right way and he mentions it.

 

[Pablo]

These "surge" suppressors are good, but no mention of more sophisticated voltage line monitors?

There are spikes that can harm the circuitry of some equipment that won't blow a MOV. Some of the line monitors combine both, and you can read the spikes over time. I have no protection now, and am thinking about the ICM 493. Anyone use one?

ICM493 | ICM Controls

Learn more about ICM493 from ICM Controls. ISO Certified manufacturer.

www.icmcontrols.com

https://www.amazon.com/ICM-Controls-ICM493-Monitor-Supression/dp/B01M16A7P3