My comfort alert doc states that the compressor common needn't run through comfort alert for it to work properly, so that suggests that CA ignores the C wire

Reviving an old thread here.
I have a Synergy3 (5 years old) and the manual states there is a fault output from the unit that can be used for an LED, I believe. I'd like to connect this to the Honeywell prestige equipment interface module to display an error message on the thermostat. The EIM has dry contact inputs.

Does anybody have experience doing this?

Thanks

It's a shame G.O. Joe hasn't been around.

We don't have the EIM, and we have Envision units. I strongly suggest using the ARB kit as previously mentioned to prevent possible problems (and having your dealer do the work.) Through the ARB, we connected the LO terminal on our Envision equipment to the L terminal on the thermostat. Works great. The Prestige error display is large, (similar to the change filter reminder.) I just look at our thermostat before bed and maybe in the morning for any messages.

Just throwing ideas out there - I wonder if you could bypass the EIM entirely and wire as we did for the lockout alert? Check with a professional.

The buzzer in the previously posted link did not work (they were cheap - so not a big deal.)

Please let us know how you make out.

I'm planning to have the installer come out and put in the intellistart system, and hook up the fault output to the EIM on the prestige. So I'm trying to educate myself on the best way to do this. I'm not familiar with the ARB kit - what is this? If the ARB facilitates connection of the fault code to the thermostat for you, I'm certain it could be used to do the same with the equipment interface module.

My understanding is that the ARB kit (from Water Furnace) is an isolation relay. As used here, it's a safety measure used so that the Prestige (and other Honeywell thermostats) can't output voltage when in Emergency Heat mode through the L terminal back to the electronics in the geothermal system. If this occurs, at best nothing may happen, and at worst fried geothermal and/or thermostat circuitry. Better safe than sorry.

We had the IntelliStart installed as well. Works great with our generator.

If I understand the equipment interface on the prestige, the fault signal is supposed to be connected to a dry contact on the EIM - there could be no signal transmitted through this, just a close/open of the dry contact circuit. I think what the EIM needs is a circuit to be closed. I'm not sure if/how the fault signal on the synergy could be used to close the circuit on the dry contact input of the EIM. Maybe the ARB kit is used for this?

It's a shame G.O. Joe hasn't been around.

Be careful what you wish for...

I have installations with Prestige 1.0 and the Prestige IAQ (includes EIM) with WF Envision packaged units. The unit will display lockouts to the Prestige without the ARB relay. Maybe the circuitry in the Prestige can handle a 5vdc signal.

The thing I am concerned with is Honeywells documentation somewhere says they apply 24vac to the L (lockout) terminal when the thermostat is set to EMERGENCY HEAT. I have not tried this to see what happens (at worst frying the Envision control) and I'd rather not try. In my case with the Envision packaged unit and control will call aux heat on a lockout anyway (so no need to switch Tstat to Emergency.

I suppose at this point it would be prudent to use an isolation relay like the ARB in case someone does change to Emergency if it could cause a problem.

Posted By G.O. Joe on 11 Jan 2012 07:03 PM

Be careful what you wish for...

I suppose at this point it would be prudent to use an isolation relay like the ARB in case someone does change to Emergency if it could cause a problem.

Welcome back!

You could use the thermostat security features to prevent switching modes, but the consequences could be worse than frying a geothermal system. 

Would you have the wiring details for either installation (with or without the ARB)? I think it would be a good idea for me to get the ARB, if it's not too expensive. Thanks

ergnut

The dry contacts you mentioned are assignable inputs on the New Prestige IAQ 2.0. I have no experience with these yet. However, the EIM does have an L terminal that will accept a powered signal on lockout (if not used for Economiser or TOD functions). You can use the ARB to receive the lockout signal from the Envision board per the instructions and power the secondary side with 24vac on closure to the Prestige L terminal.

If you do have the Prestige IAQ 2.0 and you want to use the assignable input, this video will help-

http://www.forwardthinking.honeywell.com/demos/new/8_UsingDryContacts.wmv

Posted By jim on 11 Jan 2012 10:13 PM I think it would be a good idea for me to get the ARB, if it's not too expensive.

The ARB without installation (not complicated for a competent installer) may have been in the $25 to $50 range if memory serves.  Cheap insurance.  It's just a small board with a relay on it.

G.O.Joe, thanks for the Honeywell link.

I did some more exploring in the site and found a RedLink Internet Gateway.  It will be nice to be able to view/control our system via the Internet, phone, etc.  I called Honeywell and was told it works with Prestige versions 1.0, 2.0, and other RedLink Honeywell devices.  Here is a link for those interested:

http://www.forwardthinking.honeywell.com/products/wireless/total_connect