A/C ruined by LIGHTNING, need help

[Ignoramus9242]

Sunday night, a lightning struck a tree in my yard. See pictures at:

During that day, it slowly became apparent that the A/C is not working. I live in a single family house and we have a relatively modern Tempstar A/C. Here's what is known to be working: the outside condenser/fan unit is running fine. The thermostat on the 1st floor is fine and sends 27 VAC downstairs.

The circuit board APPEARS to be okay as it sends 127 volts down to the speed control box, which in turn is connected to the motor. There is nothing obviously burned on the control board, and the fuse there is fine also. (central circuit breakers are also fine obviously).

As far as I understand, the speed control box has capacitors that start the motor. The motor is connected to the box with a green ground wire and red, yellow and blue wires. If any combination of these wires is powered briefly by 127 volts, as I tried, the motor vibrates but does not turn. There is no capacitor box on the motor, so I concluded that the capacitors in the speed control box are for starting the motor.

There is also a separate bunch of small wires going from the board to the control box. It is possible that they somehow erroneously tell the speed control box not to start the motor. Hard to say. So far I see two possibilities.

1. The speed control box is fried.

1. Somehow the board is damaged and even though it sends 127 volts to the inputs of the speed control box, it incorrectly tells the box via small wires to not start the motor.

The speed control box is easy to replace.

What should I do here? Try to find a replacement speed control box?

We called a bunch of A/C places, they said they'd call us back, but no one did. So I figured I can as well try to do it myself.

i

[Ignoramus9242]

Forgot to say, there is a bunch of dip switches on the box, maybe I can switch some of them to get the blower motor running continuously?

Also, I do NOT have the manual.

i

[mark Ransley]

I dont know about ac but call your insurance co and check everything electrical in your house, you may find you have no heat to. I have been through 2 lightning hits, It will mess up everything

[Ignoramus9242]

Thanks.

I sort of agree. I did not power the motor for more than 3 or so seconds. So I am sure that I did not damage it further.

i

[gini52]

=== You do have homeowner's insurance, don't you? Ours covered lightning damage to our submersible pump. === ===

[Oval]

Sorry, I usually just swap out Lightning stuck units. One guy thought he knew what was wrong and told me he just wanted to replace the compressor..."Thats all thats wrong with it" he said. So I did as the customer asked and told him, there may have been other damage. 2 weeks later I went out to the house and there was a time delay blown, the next week there was a bad cap and fan motor went dead. Finally I went out and replaced the board on this Dump Janitrol...(some janitrol's are nice but most are a dump) and I asked him. "Was it worth it?" He replied "What?"

It cost you almost double, what it would have been for a new unit, if you just listened to me. He just bit his lip and scrawled out the last check to me...

New unit $1430

Customer's calls and do> Sunday night, a lightning struck a tree in my yard. See pictures at: >

[Ignoramus9242]

Thanks. In my case though, the unit itself was not struck by lightning, but a tree 50 ft away was.

i

[Noon-Air]

Had a call where a tree was hit 50 yards away... it took out the entire control system, and also took out the air handler fuse block (blew it apart). then there was the small problem of a 12 inch hole blown through the side of the condenser coil. The customers insurance paid their pittance, and the customer ponied up the rest for a complete new premium system.

[mark Ransley]

you air failure im sure is related to the strike, a strike at my house afected houses 250 ft away.One house 200 ft away said they had it shoot out their sockets,, and yes as Oval said you dont know what is wrong or WILL fail next, lightning can weaken everything. Time to call your ins broker,

[Dr. Hardcrab]

"Ignoramus9242" wrote

I read all of the responses, and I may be missing something here, but is this a window unit?

The reason I ask, is because most split system units are 240 volts. Are there fuses in the disconnect box? Is it possible one is blown (from the lightning strike)?

If it's a 240V unit, it's not going to run with just 127V.

[Edwin Pawlowski]

I'd question what he is checking. One leg? A low voltage control? Ed

[Dr. Hardcrab]

Exactly.

[Ignoramus11219]

It is the central A/C unit. Split system, the condenser is outside, the evaporator inside. What was nto working was the inside furnace fan. The outside part is powered by 220 volts, the inside part is powered by 120 volts.

I was actually correct, what was broken was the speed control. The first A/C guy who came was not very bright, he was saying things like "you need to replace the board" without a shred of evidence. I have a feeling that he was just fishing for work. I asked him, why do you think the board needs replacement, and he started mumbling. I asked him if he tested anything wuth a voltmeter, he said no.

With help of previous owners, I located the installer of the unit, when it turned out that parts warranty still applied. That guy was much better, he correctly diagnozed a speed controller problem, brought in a replacement and that fixed the unit. I only paid for his labor, not the part.

i

[profft]

Good one

[Ignoramus11219]

Actually, I did no damage to the motor, my personal diagnosis was correct, what was broken was the speed controller, the first A/C guy was either a fraud or ignorant, so I did not hire him, and the second one replaced exactly what I said and everything works wonderfully. The second guy was the person who installed the A/C in the first place and appeared very experienced and intelligent to me.

I am not stupid and understand that incorrectly applied line voltage can burn the motor. But in this instance, (no starting part on the motor itself) it could not if applied for a few seconds. Note that the motor itself had no starting capacitor, so windings were the only thing to damage. Besides, I did ask some retired father of a friend of a relative about it and he did say that I could try.

i

[Oval]

A gas furnace?..most are 120V

220V are most AHU's with electric heat.

[Oval]

[Dr. Hardcrab]

Heatpump sytems (usually) are 240V (on the a/h).

[Ignoramus17897]

telnet://Time.Darktech.Org

This is a resolved issue for me, but the inside unit runs on 115V power, NOT on 220. I am sure of that. There is no reason to use 220V there anyway, unlike on the condenser unit.

i

[Dr. Hardcrab]

"Ignoramus17897" wrote

If I remember right, I never heard what type of equipment it was. If it's a heat pump I have NEVER seen an air handler that ran on 115V. I'mm not saying there AREN'T any, just have never seen one. Now if you are talking about straight A/C A/H or an A/C tied in with a gas/oil furnace, I can see that.......