Original message
| SScoulter
 |  "New to the board..."
, posted Wed 10 Aug 10:22  
Hello all, just wanted to say "hi". I own and operate a HVACR business in Little Rock, AR. This looks like a very interesting site and I look forward to spending some time with you all.
Sam
President Sam Coulter Service Inc.
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Replies:
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| jvmiller99
| "Re(1):New to the board..." , posted Thu 11 Aug 08:25
Can you help me with the post Armstrong ultra 80 blower starts and stops
JV
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| | sscoulter
| "Re(2):New to the board..." , posted Thu 11 Aug 09:09
quote:
Can you help me with the post Armstrong ultra 80 blower starts and stops
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I can certainly try. Tell me more.
President Sam Coulter Service Inc.
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| | jvmiller99
| "Re(3):New to the board..." , posted Thu 11 Aug 11:09
My upstairs unit located in the attic, has a problem where the blower fan starts the stops it does this several times before it stays started. Going in the attic I can hear a relay engage, the blowere will kick over once and I hear the relay disengage. This happens several times before the blower fan will stay on. Also while the a/c is running the blower will stop and the start/stop cycle will start again. I replaced a 7.5mfd/370vac capacitor on the blower, but it did not resolve the issue.
JV
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| | sscoulter
| "Re(4):New to the board..." , posted Thu 11 Aug 11:38:
quote:
My upstairs unit located in the attic, has a problem where the blower fan starts the stops it does this several times before it stays started. Going in the attic I can hear a relay engage, the blowere
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Ok first if you can hear the "relay" engage and disengage it is probably not the fan motor or capacitor. When the thermostat is set to cool and your fan is doing it's stopping and starting routine does the condenser continue to run or does it start and stop as well?
How old is your furnace? Is it new enough to have a circuit board or does it have a separate fan control relay?
I check a couple of things. First, let's prove the voltage (24volts) from the thermostat is constant when calling for cool. If you have a separate fan relay you can check it with a volt meter to determine if voltage is falling off or if the relay is simply breaking down. A fan relay is just a little box that should have four wires going to it. Two of the wires are your low voltage side (24volts) and the other two should be the line in (120 volts) and line out wires. When your system is off, voltage will exist only on the line-in post. When you call for cool your thermostat should send 24 volts to one side of the low voltage side of the fan control energizing the coil (the other wire on the low voltage side is a common) and closing the switch. This will send high voltage out the other wire and on to the fan motor. Using a volt meter, put one of your test leads on one side of the low voltage side of the fan control and the other lead to a common or ground. Now have someone turn the unit on and observe the meter. If voltage is dropping off when you hear the relay disengage then we will know to look elsewhere for the problem. If voltage remains constant while your relay is turning on and off then you have a bad relay.
Now, if the voltage is dropping off then more than likely you have a bad thermostat.
If your furnace is new enough to have a circuit board, put your test leads on the "G" post on the board with the green wire from your thermostat. This is where the low voltage will be coming from the thermostat to the board to tell it to turn the fan on. The same rules apply, if voltage remains constant while the fan is turning on and off then more than likely you may have a bad circuit board.
Does this event happen only on start up or does this happen even after the motor has been running for a while? If it only at start up I would suspect a t-stat problem. If after the start/stop issue the motor runs well I would doubt you have any problems with the fan itself.
Let me know a little more info and we can get to the bottom of this.
President Sam Coulter Service Inc.
[this message was edited by sscoulter on Thu 11 Aug 11:39] |
| MasterTech
| "Re(1):New to the board..." , posted Wed 10 Aug 23:17
Welcome. Its kinda fun and you can learn somethings here too.
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| | jvmiller99
| "Re(2):New to the board..." , posted Thu 11 Aug 11:58
I am not sure if the compressor is still running. The start/stop issue occurs when it first comes on and then happens while, in what I am going to call the middle of the cycle. In other words the blower stops blowing while I can still hear the a/c unit working (which could mean the compressor is running) and goes into the start/stop issue. I will check some of the things you listed this evening and let you know what I find.
JV
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| | sscoulter
| "Re(3):New to the board..." , posted Thu 11 Aug 12:05:
quote:
I am not sure if the compressor is still running. The start/stop issue occurs when it first comes on and then happens while, in what I am going to call the middle of the cycle. In other words the blow
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It sounds like the condenser is still running during this event and that's good. When trouble shooting a problem like this just remember you can always start at the problem and work your way back through a process of elimination until you find the cause. Electrically, HVAC systems are linear in function. A happens first, then B and then C and so forth. Just prove to yourself one step at a time that each component is good and just work backwards until you have the problem solved. Good luck and let me know what you find.
Sam
President Sam Coulter Service Inc.
[this message was edited by sscoulter on Thu 11 Aug 12:05] |
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