Air Conditioning - Help! Just changed my Fan Controler (ICM 275) now system "false starts" cooling

A/C Question: Just replaced Fan Control Unit and now the Blower false starts every time the Cooling goes on
I had an HH84AA009 in my carrier air handler. This air handler does both cooling and heating. A few days ago, the blower stopped turning off and remained constantly in the "on" position (even after moving the switches on the thermostat to "off" and Auto)

When I'd power off my system and open the unit, If I tapped the relay with a screw driver the fan would turnitself off, however once it went on again it wouldn't turn off.


I replaced the unit with a new ICM275. I replaced wire for wire one at a time, so I am pretty sure that I did it correctly.

Now, the fan works well, however when you put the unit into cooling mode, the blower will go on, and then as soon as the cooling kicks in, the unit kind of "resets" the blower turns off and then tries many consecutive "false starts"


Have I done anything wrong?

Is this newer controler board (with new kind of relays) different and therefore I need to change the wire cconnections

Until you get this resolved - are you able to get a/c to blow if you turn the stat to fan "on"(not auto) and put in "cool" mode?, or not? And what does it do in heat/auto and heat/on, modes?

What are the carrier model and serial numbers. You may have changed with the wrong control.

The new replacement board is different than the original one. The old one has the big old style relays while the new one has the newer relays. This new Board (ICM275) is the currently availible replacement for many legacy Carrier boards including the HH84AA009 (which is the one I had). The board has the same form factor and all of the connection terminals are labeled exactly the same as in the old board. As mentioned before, I connected the wires from the old to the new one at a time to make sure I got them right.....

There is a delay feature that can be adjusted by moving a potentiometer dial.

Maybe somewhere out there knows if these newer boards (that use SPST-NO blower relay, SPDT blower speed relay and SPST-NO relay for humidifier) require any wiring changes from the old boards (that use SPST-NC or DPST-NC heating fan relay and DPDT cooling fan relay 2f)

THe board is made by ICM controls and the schematics are on the icm site.
0 seconds ago

update, it seems that when I set the blower settings at the stat to "on" instead of "auto" both the cooling and blower work. When I change the setting to auto, I get the problems again

If you have cooling with the fan in On mode I would set it that way til monday morning and call the local carrier office for tech support they may not help you as some of will only support their dealers but it is worth a try it sounds to me like one of the relays is functioning differently in the new configuration there should have been an instruction sheet in the box describing any changes and what you would have to do about it

If you have cooling with the fan in On mode I would set it that way til monday morning and call the local carrier office for tech support they may not help you as some of will only support their dealers but it is worth a try it sounds to me like one of the relays is functioning differently in the new configuration there should have been an instruction sheet in the box describing any changes and what you would have to do about it


Any a/c tech that has to repair these carrier units has no choice today but to put in this newer icm275 board, so it must be a common issue, I also supect that relays now function differently.
Here is a quote from the manual, however I don't understand it enough to know what to modify:

"Operational Differences and Added Features
The following is a description of the slight operational differences and added features. Refer to ICM275 Component Layout (Page 3) for location of control center components.
Operation with new blower and humidifier relays:
The previous design control centers used a SPST-NC or DPST-NC heating fan relay (HFR of E2) and a DPDT cooling fan relay (CFR or 2F) for blower and humidifier terminal operation. This new control center uses a SPST-NO blower relay (BLWR) and a SPDT blower speed change relay (hi/lo) for blower operation, and a SPST-NO humidifier relay.
1. The low-speed blower will not operate on a transformer failure as on previous designs.
2. If JW1 jumper is cut between R and GH terminals, a constant low-speed blower will occur without any thermostat inputs to the control center. A GC or Y signal to the control center will not bring on the hi-speed blower for cooling operation. JW1 jumper must not be cut on cooling applications.
3. The humidifier H terminal is energized with low-speed blower operation. In cooling operation, the humidistat and humidifier water supply should be turned off to ensure the humidifier does not operate."


I think ECMAN was on to something.

redmachodevil, the reason I asked for the CARRIER unit model and serial number was so I could go to Carrier and have the wire diagram for it in one window and the ICM in another to help you.

Your posting of the old Carrier part number and new ICM number allows looking at the ICM only.

Again, what is the model and serial number of the unit? Not the board, the actual unit it is installed in.

I honest think it would help you if one could say "Move this yellow wire from here to here".

Chris

update, it seems that when I set the blower settings at the stat to "on" instead of "auto" both the cooling and blower work. When I change the setting to auto, I get the problems again

Does that mean then that you get to enjoy a/c? while you figure out what reconfiguring you have to do with the board's terminals?

I put in this new ignition control board last year and remember having to adapt to their insructions, and I was disgusted that they just could not sell me the same old board to keep my labor costs down to person I did the work for, instead of having to read all them pages, and diagrams.

redmachodevil, the reason I asked for the CARRIER unit model and serial number was so I could go to Carrier and have the wire diagram for it in one window and the ICM in another to help you.

Your posting of the old Carrier part number and new ICM number allows looking at the ICM only.

Again, what is the model and serial number of the unit? Not the board, the actual unit it is installed in.

I honest think it would help you if one could say "Move this yellow wire from here to here".

Chris


the model is 58SSB130-bc
series 120
Serial # 0988C75815

The inside cover has a shematic on it, labeled 309260-401 rev d

this is a link to what the old board looks like:
http://i516.photobucket.com/albums/u327/redmachodevil/hvac/hvac014.jpg


this is a link to how the new one is wired:

http://i516.photobucket.com/albums/u327/redmachodevil/hvac/hvac004.jpg

http://i516.photobucket.com/albums/u327/redmachodevil/hvac/hvac005.jpg

http://i516.photobucket.com/albums/u327/redmachodevil/hvac/hvac008.jpg

Cut the resistor.

55SS is not a Carrier model number. Ticked me off did more research.

Look at page 3 of the ICM install inst. Resistor R18 not cut, no blower on call for Y.

Cut the resistor.

55SS is not a Carrier model number. Ticked me off did more research.

Look at page 3 of the ICM install inst. Resistor R18 not cut, no blower on call for Y.

58SS

also.. I thought about the resistor however clearly says not to cut resistor for cooling application or twinning only for heeting... this unit is both heating and cooling

Yesterday, 58SS would not come up at Carrier, meaning not a good model #.

Today, try once more, bag there it is.

Do you have the manual, or want a pdf of it?

Will study later and repost.

Chris

Only real difference I see is the relays, which is no big deal.

I don't see the connector for the furnace controls, not hooked up maybe freaking it out.

Looks like all other wires are correct.

Did you try the last Tshoot step on page 5 to eliminate the stat?

Only real difference I see is the relays, which is no big deal.

I don't see the connector for the furnace controls, not hooked up maybe freaking it out.

Looks like all other wires are correct.

Did you try the last Tshoot step on page 5 to eliminate the stat?




Yes, I tried it without the Tstat.

I called ICM and they told me to cut R18 as you mentioned elsewhere JD.

I want to just make sure that is it as i'm not looking forward to have to resolder it if it ends up not being the problem.

I thought the same thing about resolder if incorrect.

Hmm, Idea, how about unsolder R18 just incase you do need to resolder?

Hi.
I have a Carrier 58DHB furnace which had a Carrier HH84AA021 fan blower control board. The board failed (relay contacts welded together) and the fan stayed on even when the air conditioning and heating were set to off.
I replaced the Carrier HH84AA021 with an ICM275 and I observe that the blower fan works properly when the thermostat calls for heat, but the blower fan remains off when the air conditioning compressor is ON and the fan is set to AUTO. If the fan is set to ON it operates OK.
The ICM manual says the blower will operate at high speed for cooling if resistor R18 is cut, but it implies that for heating the blower will operate at low speed.
Should I cut R18, or do I have to make other wiring changes?