Fan Blower Runs constantly on or Off !!! - DIY Chatroom

bluelatin · 11-04-2009, 06:36 PM

Hey gang, first of all thank you to all who answers.
Now my problem: Got an old package unit Heil Model PH5530AKA3 a/c and heat works fine but fan blower continues to run even when unit is off!!
Could it be the relay? and if it is how do I find out what kind to replaced with since unit is pretty old.
Once again, thank you in advance
Blue

mikef54 · 11-04-2009, 08:10 PM

Not sure what type of fan control it has. Some have a white button you can pull out for the fan to run all the time.Others have a time delay relay to cycle the fan. The time delay relay should have 2 wires feeding it 24 volts to it to close it after a call for heat from the thermostat. And 2 wires on it that are 120 volts that goes to the fan,one hot wire to the control,the other feeding the fan when the relay closes. I would trace the hot wire from the fan back to where it comes from a control to see what type of control you have.

bluelatin · 11-04-2009, 08:19 PM

hey mike thanks,
I know a little of it.
There is not white bottom it is a relay with six connectors to it, the black wire goes to the relay and also to a low voltage 24v relay, the orange or yellow goes to the contactors. Some posts mentioned a fan relay being stuck, I do not see any thing in mine that indicates any contacts to be stucked (if that makes any sense ).
Hey thanks once again and hope this will help you help me more,
blue

Houston204 · 11-05-2009, 03:23 AM

Turn off your stat and check these wires.

Does the fan turn off when you disconnect the green 24 volt wire to the G terminal at your heatpump?

Does the fan turn off when you disconnect the black high voltage wire from terminal 4 at your fan relay? (IFMC)

Does your fan turn off when you disconnect the white low voltage wire from terminal 5 at your heat sequencer.

I'd say to also remove the black high voltage wire from terminal 2 at the sequencer but if this contact is stuck the heat strip could also be stuck and could be damaged when you remove the terminal 2 wire. So a better test would be to measure for 240 volts AC from sequencer terminal 2 to fan motor Common, which is L2 at the contactor.

High voltage is dangerous and a pro might be cheaper than a trip to the E.R.

mikef54 · 11-05-2009, 07:27 PM

Houston's post is right on. If you can follow the wiring diagram it will lead you to the problem. just be careful of working on a system that has the electric still on it.

bluelatin · 11-07-2009, 10:16 AM

Houston and mike, thanks a bunch for the input.
I just got a couple of questions (I'm a little stupid in my end ):
1st: the second set of schematics are right on for my unit.
2nd: when a test those wires (and here is my dilemma) if the fan turns off that means that is the problem? and what if it turns off when I try all of them.
3rd: I am a computer/tv tech so i always work around HV tv sets
4th: I suspect it is the relay but I can not find one similar to the one in my unit to check prices....any sugesttions? or are they pretty much standard?

Hey once again thank a bunch

Blue

Houston204 · 11-07-2009, 11:27 AM

The second diagram would be on the unit, the first diagram comes in the box with electric heat strips and wouldn't be on your unit if you do not have heat strips. If you have do heat strips, the first diagram probably got tossed by the installer.

If your fan always runs, you may have a faulty stat or a short in the stat wire to your heatpump. If your fan turns off when you remove the G wire, it will verify this.
If the 24VAC signal from your stat to the G terminal isn't the culprit, the fan relay and the heat sequencer controlling your blower should be checked.

If you are TV tech, I'm sure you can test these wires with a meter.
1. Turn off your stat. Verify that the Fan is set to Auto.
2. Measure C to G for 24VAC at your heatpump. It should not be present.
3. Measure for 24VAC at your sequencer coil (5 & 6) and at your fan relay coil (1 and 3). It should not be present with the stat off.

4. Disconnect terminal 4 on your fan relay. If the fan still runs it's your sequencer.

The heat strips would be located at the blower as shown in my first pic. The manual for your unit can be found at the URL displayed near the bottom of my second pic.

Be Careful. Electricity hurts more when you are kneeling in the dirt or mud.