AC contactor question (1 Viewer)

[BlueRaspberry]

My voltage tester lights up when I touch A and B, but it doesn't light up when I touch C and D.

That means the contactor is bad, right?

 

[Galbreath34]

Don't cut the red wire. I saw that on TV once.

 

[guidomerkinsrules]

I predict post #12 or after will be your first legit response

 

[superchuck500]

Good luck. We ran off all the legitimate contributors to society. All that's left are a bunch of wise cracking liberal arts types.

 

[Stealth Matrix]

Did somebody say.... Contact?

(.02 deposited to my account)

 

[St4ever]

No. What it means is the contractor has not been engaged yet. You have a smaller current that switches the. Contacts on and off. Your system (thermostat) does the primilary work. How's your capacitor? Does the outside dan come on? The contactor only turns on the high voltage compressor. If everything else is working then it may be the contactor

 

[MrVoodoo]

No. What it means is the contractor has not been engaged yet. You have a smaller current that switches the. Contacts on and off. Your system (thermostat) does the primilary work. How's your capacitor? Does the outside dan come on? The contactor only turns on the high voltage compressor. If everything else is working then it may be the contactor

I know someone that can help if you can't turn your Outside Dan on...


But he's correct, your contacts aren't engaged. If you don't have a true voltmeter to test, I'd recommend getting someone in there. The contactor should pull in if you have voltage across the coil - which from the picture appears to be the black wire to the left and maybe the yellow wire on the right, can't see the right too well. I'd assume that you'd be looking for 24volts, but it may be a 110v coil. One leg of the meter to the contact point and the other leg to ground - should have (assuming) 24v on both. If you have 24 on one and much less or 0 on the other - you've got a bad coil on your contactor. If you don't have voltage on either side, any number of problems can be wrong with it. Again, I recommend getting a professional to check it out if you don't have the proper tools.

oh and if you have 24 on both - could be a bad contactor, or could be a couple things: pitted contacts that don't make a good connection or my favorite, a slew of ants that have died in the contactor and keep it from closing and making a good connection. Though I'd say from the picture it doesn't appear to be ants, but still could be.. they typically get in and when they get fried they keep attracting more for a while - most of the time you can see it when you open the box, dead ants on the frame under the contactor.

 

[MrVoodoo]

I predict post #12 or after will be your first legit response

Almost got halfway there before he got a legit response from St4ever

 

[St4ever]

Almost got halfway there before he got a legit response from St4ever

Sorry but I never joke around when electricity is involved

 

[Galbreath34]

I'm shocked.

 

[BlueRaspberry]

No. What it means is the contractor has not been engaged yet.

But if it is engaged, shouldn't the voltage tester light up when I touch C and D?

When I turn on the AC, everything indoors works fine, but the condenser outside does nothing. I took a stick and spun the fan blade to see if it would keep spinning, but it didn't.

Also, I had someone turn the AC on when I was outside listening to it and it didn't make any noise. Shouldn't you be able to hear a click when the contactor engages?

 

[MrVoodoo]

But if it is engaged, shouldn't the voltage tester light up when I touch C and D?

When I turn on the AC, everything indoors works fine, but the condenser outside does nothing. I took a stick and spun the fan blade to see if it would keep spinning, but it didn't.

Also, I had someone turn the AC on when I was outside listening to it and it didn't make any noise. Shouldn't you be able to hear a click when the contactor engages?

There are a few things that happen before the contactor engages - you'd have to read the wiring schematic to determine what exactly that is. My guess is that you've got a bad capacitor (but that's just a default guess from experience working with units - I always check to see if coil is energized, if not then I check capacitors - you'd need a meter that can read microfarads).

You are absolutely correct, IF it is engaged, the voltage tester would light up when you touch C and D.

So now you have to find out if the system is trying to engage it to determine if the contactor is bad or not. If it isn't trying to engage it, you've got to determine why it isn't. If all you're using is a light up voltage testing pen, you don't have enough from that pen to properly troubleshoot it. There are things in there that will seriously hurt or kill you - I've heard stories of experienced HVAC technicians who have made mistakes and have literally been blown out of their boots from the charge in the capacitor. If you don't have the right tools or general knowledge, I would recommend not being in there at all because again you can get seriously hurt or killed.

If you're experienced with electricity, capacitors, and the such with proper testing equipment - then I'd be willing to take a look at pictures of the schematics to give you an idea where to check. There are a few things that can keep your contacts from engaging and/or not working when the coil is energized. You have to determine if the coil is energized before it matters whether or not you have voltage on C and D. Please don't get yourself hurt though.

 

[superchuck500]

But if it is engaged, shouldn't the voltage tester light up when I touch C and D?

When I turn on the AC, everything indoors works fine, but the condenser outside does nothing. I took a stick and spun the fan blade to see if it would keep spinning, but it didn't.

Also, I had someone turn the AC on when I was outside listening to it and it didn't make any noise. Shouldn't you be able to hear a click when the contactor engages?

Have you checked the ball bearings?

 

[MrVoodoo]

Have you checked the ball bearings?

Speaking of which... "Balls to the wall" - I don't quite get that meaning, I mean if you go balls to the wall you're probably not going anywhere, right? Challenge: Run at the wall with your pelvis forward so you run balls to the wall, bet you won't be running much when you do go balls to the wall.

 

[superchuck500]

Speaking of which... "Balls to the wall" - I don't quite get that meaning, I mean if you go balls to the wall you're probably not going anywhere, right? Challenge: Run at the wall with your pelvis forward so you run balls to the wall, bet you won't be running much when you do go balls to the wall.

Now you're getting into our wheelhouse! I approve of the new direction of this thread.

Before googling, I'm trying to imagine what the source could have been. Perhaps it's a racquetball expression? Ha.