SURGE ⚡️

[Doc13067]

Hey guys, I need the brains on this forum. I put in electric for 2 mini splits and my HVAC pal installed them in 2021. Both got fried this year and we believe it was a surge. He had to replace all major components of both and it cost about the same as entire new units. Before he did that I put SPDs in. A Siemens Bolt Shield 35kA (that’s the only one my supply had in stock, I know it’s low) and two 100kA SPDs that I got from a HVAC place, one on each mini split disco. A month later it happened again!!!! Unit 1 had the board blown and Unit 2 survived. The Siemens boltshield is showing red trip flags and the 100kA on Unit 1 no longer has a lit green LED. Unit 2 still shows a green LED. At least 135,000 amps worth of surge busted through the gates and fried Unit 1 in the last month. The house is very well grounded but it is a farm house in the middle of nowhere (3 inch spiders all around). There is no evidence of lightning damage anywhere but that’s not to say it didn’t occur. My gut tells me this is a utility thing because lightning hasn’t declared war on us in the last 3 years but something certainly could be up with their equipment. Does anyone have any ideas?

WWLFD?

 

[LarryFine]

WWLFD?

I would find out what the connected-equipment warranty is. That's the only thing that matters.

 

[Doc13067]

I would find out what the connected-equipment warranty is. That's the only thing that matters.

I appreciate it. I will advise the HVAC guy. But the thing is it keeps happening. There’s something ongoing and I have no idea where to look. And I thought I installed a ton of surge protection and it only lasted a month or so.

 

[LarryFine]

But the thing is it keeps happening.

That's insane. After the first mishap, what was done under warranty?

It's ridiculous to buy the same equipment after the first failure.

 

[Doc13067]

I’m not sure I can ask my HVAC guy and see if any of it was covered. But the fact that two of my surge protectors are blown out and these units have been installed by him many other times (and they were fine for 3 years at this location) wouldn’t you think there’s a poco problem possibly?

 

[ramsy]

At least 135,000 amps worth of surge busted through the gates and fried Unit 1 in the last month.

You need a MIL Spec SPD.

 

[Doc13067]

You need a MIL Spec SPD.

Is that something you put on an AR15?

 

[ramsy]

empshield.com

 

[suemarkp]

I'm not sure how helpful the SPD amp ratings really are. If you are subjected to a milder but long lasting surge, I would think that will blow out the SPDs just as easily as a short duration high voltage spike. Amps aren't pushed in a surge, they are drawn based on how high the voltage goes and the system impedance allows.

Power logging could maybe catch what is going on, but how often does it occur and do you want to leave expensive recording gear there for months and months?

I don't know if anyone makes a shunt trip type of SPD that monitors things and if it is long duration shuts off the main. And can you even get a shunt trip main for that panel.

Also assume these are 240V mini splits, so it isn't a loose neutral problem.

 

[Hv&Lv]

Also assume these are 240V mini splits, so it isn't a loose neutral problem.

Aren't the control boards 120V?
Not sure I would rule out a neutral problem quite yet.

 

[David Castor]

The SPDs need a really good, direct ground connection to function correctly. I'd make sure you have good quality SPDs from a reputable manufacturer installed as close to the units as possible. It sounds like yours are installed at the local disconnects, which is good. There is a lot of junk out there. The surge protection needs to protect both hot legs to ground and the neutral to ground if there is a neutral.

I'd also ask the local utility to verify their grounding at your service and see if there is a surge arrester on the primary side of your transformer. I'd definitely report your issues with the utility as well as your insurance company.

 

[letgomywago]

Aren't the control boards 120V?
Not sure I would rule out a neutral problem quite yet.

First thing I thought but minisplits are usually 240 no nuetral with a step-down circuit.

 

[mtnelect]

We install "Daikin", and the installation instructions require a GFCI must be installed for protection.

 

[ramsy]

I'd also ask the local utility to verify their grounding at your service and see if there is a surge arrester on the primary side of your transformer

Copper thieves got ~8ft of #10cu electrode from our power pole. Spectrum has no reporting option, or customer service contact, so code enforcement is the only way to get these fixed.

 

[Hv&Lv]

Copper thieves got ~8ft of #10cu electrode from our power pole. Spectrum has no reporting option, or customer service contact, so code enforcement is the only way to get these fixed.

Code enforcement? This must be a personally owned pole..
That old wood U guard with the stranded connected looks as though it has happened before

 

[ramsy]

Code enforcement? This must be a personally owned pole..
That old wood U guard with the stranded connected looks as though it has happened before

Doubt its personally owned. If code enforcement rejects report we be SOL, until zapped by lighting from un-bonded cable.

Probably has been done before, the way they ripped it out of the ground.

 

[Hv&Lv]

Doubt its personally owned. If code enforcement rejects report we be SOL, until zapped by lighting from un-bonded cable.

Probably has been done before, the way they ripped it out of the ground.

Reason I say personally owned is if it's a utility pole code enforcement has nothing to do with it.
Someone would have to call the utility. Some will come on and fix it, others, especially IOUs may never come out..

 

[ramsy]

Someone would have to call the utility

Thanks for that pointer, will try utility.

 

[ramsy]

Someone would have to call the utility.

Utility lineman said stollen copper electrode was connected to fiber optic service, which wont subject customers to hazard.

Recommends let fiber company find it next time they service the junction.

 

[Doc13067]

Just to update, poco was out and verified the issue was from their transformer. Whatever it was they fixed it. Good luck to the client trying to explain their equipment blew out 15k in equipment.