39 replies to this topic

[Dan Webster]

Maybe that bimetal heater inside that relay might be going out but just ain't gave up the ghost yet. The way that dude works is a small coil is mounted inside the thang. It takes a set amount of time for it to heat up sufficiently to turn on thangs. Then when power is removed from it as it cools down it releases components. People used to bring sequencers into my shop for me to check. I noted that taping on the side of a sicking one would release the bimetal. Obviously with all the power going into the thang you go touching the wrong thang you might get lit up. They do not cost that much, but they can sure be a pain in the ass to diagnose sometimes.

[bigcrunch]

OK my sequencer is labled as a 15sh4, google'd it looks like there are a whole slew of exchange numbers avail. trying to avoid China what brands are a good choice?

[bigcrunch]

The AMP readings I have are within range?

[jumptrout]

What are the amp readings on the heater(s) and the fan motor?

[bigcrunch]

Hey jumptrout

amp readings below

heat coil 1
start 16
run 15

heat coil 2
start 17
run 15

fan black wire
start 3.5
run 2.2

fan capacitor brown wire
run 1.75

[jumptrout]

Do the fan wires still have voltage after the fan stops?

[bigcrunch]

Only place I could test it are on the brown capcitor and yellow transformer wires, both had 120v after fan stopped and temp came up to thermostat setting.

[jumptrout]

The brown capacitor wire is semi-irrelevant.
You need a reading from yellow and most likely black to the fan motor when it stops running.
If you have 220 volts the fan motor is bad.
If you have no volts and the heaters are still on,you have a fan relay problem.

[Dan Webster]

Did you get it fixed yet?

[bigcrunch]

It has 120 volt on the yellow also black wire after fan stops.

[Dan Webster]

Could one side of your breaker be going out like this one? Click pic:

Attached Files

•  bad breaker.jpg   28.54K   4 downloads

Edited by applianceman18007260692, 31 December 2011 - 03:42 PM.

[jumptrout]

If you still have power to the heaters,verified by amp draw and the fan stops running you have a Bad fan relay. Opening too soon.
If the heaters are off,the fan should run 90 seconds longer before turning off.

[RegUS_PatOff]

maybe this info ?
Installation Manual
Direct Expansion Fan Coil Units PF1M
Sizes 018—071
im-pf1m-01.pdf

[bigcrunch]

applianceman18007260692 I took a look at the main cricuit breaker looks fine.


jumptrout when the heat and fan are off, amp draw on the yellow and black leads are .02amps. I'll check for voltage to the heat strips in the am.


RegUS_PatOff I took a look at the install manual, wiring diagram mateches to what is in the unit...

[bigcrunch]

Ok went ahead and took a look at the voltage on heat coils after thermostat shuts heat off. Has 120v to it, looks like it is coming from the light blue wire on the circuit boardrelay look at pic DSC02168 on page one, it is a dark blue once it passes thru wire connector.


It feeds back to the right side of the sequencer that has all the devices attached to it pic DSC03165.

[jumptrout]

Either I am not writing correctly or you are not interpreting correctly.
1. Put your amp meter on a heater wire.
2. Turn the heater on.
3.Heater comes on followed by the fan.
4.Fan stops running.
5. Are the heaters still drawing amps when the fan quits?
6. If heaters are drawing amps,does the fan motor have 220 volts measured at yellow and black?

[jumptrout]

Ok went ahead and took a look at the voltage on heat coils after thermostat shuts heat off. Has 120v to it, looks like it is coming from the light blue wire on the circuit boardrelay look at pic DSC02168 on page one, it is a dark blue once it passes thru wire connector.


It feeds back to the right side of the sequencer that has all the devices attached to it pic DSC03165.

All this is normal.
With the thermostat satisfied you will always have half power (120 volts) to one side (incoming) from the pwer supply. The other leg is made through switches and relays on a call for heat.
This provides 220 volts to the fan and heater.

[telefunkenu47]

Glad Im an oil man

[bigcrunch]

Either I am not writing correctly or you are not interpreting correctly. 1. Put your amp meter on a heater wire. 2. Turn the heater on. 3.Heater comes on followed by the fan. 4.Fan stops running. 5. Are the heaters still drawing amps when the fan quits? 6. If heaters are drawing amps,does the fan motor have 220 volts measured at yellow and black?

After the heat cycle, fan is off and thermostat shows no "heat on" the heat coils show no amp draw.

[jumptrout]

After the heat cycle, fan is off and thermostat shows no "heat on" the heat coils show no amp draw.

This a normal situation. Everything should be off when the thermostat temp is satisfied.
However,it has nothing to do with how you stated your original problem of the fan cycling off and the heat staying on.
I am going to take the opportunity to move on to other post and actually help someone.