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#1
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HVAC troubleshooting 220V
Hello,
Before I call the pros, I am going to do some basic troubleshooting on my central AC. The fan and compressor are not coming on. I can hear a low-voltage hum. I will start with a meter to make sure 220v is getting to the contactor and also 220v is coming out of the contactor. .. Since I don't have any experience with 220v, I would prefer to not belt myself. Out of the wall is a pink and black wire to the contactor. Where do I put the meter leads to test it? Any danger moving the leads from terminal to terminal as long as I don't hold the leads by the metal end (just kidding). Also, when the unit comes on, should I see the contactor move, or click, or what?? I didn't see anything like that, so I am thinking 220v is not getting to the unit. .. Thanks for your time. -jack |
#2
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HVAC troubleshooting 220V
If you have someone turn the thermostat up and down, you will hear the
contactor click in and drop out. It operates on 24 volts which it gets from the blower unit. Near the condenser should be a disconnect. open the disconnect and find the two terminals marked "line". If you touch the terminals of a meter across these two terminals you should get 240 volts. If not, check the breaker feeding the condenser "Jack" wrote in message ... Hello, Before I call the pros, I am going to do some basic troubleshooting on my central AC. The fan and compressor are not coming on. I can hear a low-voltage hum. I will start with a meter to make sure 220v is getting to the contactor and also 220v is coming out of the contactor. . Since I don't have any experience with 220v, I would prefer to not belt myself. Out of the wall is a pink and black wire to the contactor. Where do I put the meter leads to test it? Any danger moving the leads from terminal to terminal as long as I don't hold the leads by the metal end (just kidding). Also, when the unit comes on, should I see the contactor move, or click, or what?? I didn't see anything like that, so I am thinking 220v is not getting to the unit. . Thanks for your time. -jack |
#3
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HVAC troubleshooting 220V Followup
OK, this is going to sound nuts...The contactor was not clicking on. Out of
frustration, I banged the side of the unit (like whacking the side of a TV), and the unit kicked on. Holy smokes...there seem to be no loose wires, so my thinking is the contactor is bad. I think I will replace it. Any other ideas? I don't have a magic touch. "RBM" rbm2(remove wrote in message ... If you have someone turn the thermostat up and down, you will hear the contactor click in and drop out. It operates on 24 volts which it gets from the blower unit. Near the condenser should be a disconnect. open the disconnect and find the two terminals marked "line". If you touch the terminals of a meter across these two terminals you should get 240 volts. If not, check the breaker feeding the condenser "Jack" wrote in message ... Hello, Before I call the pros, I am going to do some basic troubleshooting on my central AC. The fan and compressor are not coming on. I can hear a low-voltage hum. I will start with a meter to make sure 220v is getting to the contactor and also 220v is coming out of the contactor. . Since I don't have any experience with 220v, I would prefer to not belt myself. Out of the wall is a pink and black wire to the contactor. Where do I put the meter leads to test it? Any danger moving the leads from terminal to terminal as long as I don't hold the leads by the metal end (just kidding). Also, when the unit comes on, should I see the contactor move, or click, or what?? I didn't see anything like that, so I am thinking 220v is not getting to the unit. . Thanks for your time. -jack |
#4
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HVAC troubleshooting 220V
RBM wrote:
If you have someone turn the thermostat up and down, you will hear the contactor click in and drop out. snip Not necessarily. Some modern electronic thermostats have short-cycle protection built in to their software. -- The e-mail address in our reply-to line is reversed in an attempt to minimize spam. Our true address is of the form . |
#5
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HVAC troubleshooting 220V Followup
Jack wrote:
OK, this is going to sound nuts...The contactor was not clicking on. Out of frustration, I banged the side of the unit (like whacking the side of a TV), and the unit kicked on. Holy smokes...there seem to be no loose wires, so my thinking is the contactor is bad. I think I will replace it. Any other ideas? I don't have a magic touch. Sometimes they stick. But one that sticks is due for replacement. "RBM" rbm2(remove wrote in message ... If you have someone turn the thermostat up and down, you will hear the contactor click in and drop out. It operates on 24 volts which it gets from the blower unit. Near the condenser should be a disconnect. open the disconnect and find the two terminals marked "line". If you touch the terminals of a meter across these two terminals you should get 240 volts. If not, check the breaker feeding the condenser "Jack" wrote in message ... Hello, Before I call the pros, I am going to do some basic troubleshooting on my central AC. The fan and compressor are not coming on. I can hear a low-voltage hum. I will start with a meter to make sure 220v is getting to the contactor and also 220v is coming out of the contactor. . Since I don't have any experience with 220v, I would prefer to not belt myself. Out of the wall is a pink and black wire to the contactor. Where do I put the meter leads to test it? Any danger moving the leads from terminal to terminal as long as I don't hold the leads by the metal end (just kidding). Also, when the unit comes on, should I see the contactor move, or click, or what?? I didn't see anything like that, so I am thinking 220v is not getting to the unit. . Thanks for your time. -jack -- The e-mail address in our reply-to line is reversed in an attempt to minimize spam. Our true address is of the form . |
#6
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HVAC troubleshooting 220V Followup
It sounds stuck. It happens, just replace it
"Jack" wrote in message ... OK, this is going to sound nuts...The contactor was not clicking on. Out of frustration, I banged the side of the unit (like whacking the side of a TV), and the unit kicked on. Holy smokes...there seem to be no loose wires, so my thinking is the contactor is bad. I think I will replace it. Any other ideas? I don't have a magic touch. "RBM" rbm2(remove wrote in message ... If you have someone turn the thermostat up and down, you will hear the contactor click in and drop out. It operates on 24 volts which it gets from the blower unit. Near the condenser should be a disconnect. open the disconnect and find the two terminals marked "line". If you touch the terminals of a meter across these two terminals you should get 240 volts. If not, check the breaker feeding the condenser "Jack" wrote in message ... Hello, Before I call the pros, I am going to do some basic troubleshooting on my central AC. The fan and compressor are not coming on. I can hear a low-voltage hum. I will start with a meter to make sure 220v is getting to the contactor and also 220v is coming out of the contactor. . Since I don't have any experience with 220v, I would prefer to not belt myself. Out of the wall is a pink and black wire to the contactor. Where do I put the meter leads to test it? Any danger moving the leads from terminal to terminal as long as I don't hold the leads by the metal end (just kidding). Also, when the unit comes on, should I see the contactor move, or click, or what?? I didn't see anything like that, so I am thinking 220v is not getting to the unit. . Thanks for your time. -jack |
#7
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HVAC troubleshooting 220V
I should have said, it'll either click on immediately or in about five
minutes "CJT" wrote in message ... RBM wrote: If you have someone turn the thermostat up and down, you will hear the contactor click in and drop out. snip Not necessarily. Some modern electronic thermostats have short-cycle protection built in to their software. -- The e-mail address in our reply-to line is reversed in an attempt to minimize spam. Our true address is of the form . |
#8
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HVAC troubleshooting 220V
"Jack" wrote in message ... Hello, Before I call the pros, I am going to do some basic troubleshooting on my central AC. The fan and compressor are not coming on. I can hear a low-voltage hum. I will start with a meter to make sure 220v is getting to the contactor and also 220v is coming out of the contactor. . Since I don't have any experience with 220v, I would prefer to not belt myself. Out of the wall is a pink and black wire to the contactor. Where do I put the meter leads to test it? Any danger moving the leads from terminal to terminal as long as I don't hold the leads by the metal end (just kidding). Also, when the unit comes on, should I see the contactor move, or click, or what?? I didn't see anything like that, so I am thinking 220v is not getting to the unit. . Thanks for your time. -jack For your own protection, back away from the unit, locate a phone and call a repairman! |
#9
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HVAC troubleshooting 220V Followup
"Jack" wrote in message ... OK, this is going to sound nuts...The contactor was not clicking on. Out of frustration, I banged the side of the unit (like whacking the side of a TV), and the unit kicked on. Holy smokes...there seem to be no loose wires, so my thinking is the contactor is bad. I think I will replace it. Any other ideas? I don't have a magic touch. Likewise, we don't have a magical crystal ball. |
#10
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HVAC troubleshooting 220V
On Mon, 16 Jul 2007 00:25:26 GMT, CJT wrote:
RBM wrote: If you have someone turn the thermostat up and down, you will hear the contactor click in and drop out. snip Not necessarily. Some modern electronic thermostats have short-cycle protection built in to their software. My whole system is from 1979, not "modern" I would think. Yet neither the heat nor the AC go on for 2 or 3 minutes after I turn it on at the thermostat, or at the power switch on the basement wall. Is that the same short-cycle protection? I have a Carrier AC and maybe a Carrier furnace too. |
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