Humidifiers and Dehumidifiers - wiring Aprilaire humidifier to Ruud 90+ w/heat pump

I have installed an Aprilaire 600A humidifier to my 1 yr old Ruud Achiever 90+ (mod UGTK 09EZAJS) with a 13 SEER air/air heat pump (mod UPNL-360 JAZ). This is a downflow/horizontal unit, mounted horizontally. My issue is the wiring. To the AprilAire controller I have wired the outdoor sensor to the ODT terminals & the humidifier to the HUM terminals. I have not hooked up the 24 vac transformer (do I need it?) I am reluctant to wire anything to the furnace yet. Should I wire this to detect furnace, blower or heat pump? (april aire gives different scenarios) My furnace does have HUM & NEUTRAL screws but I don't want to cause damage to any equipment trying to hook this up. I have read other posts , Aprl Air 600 to Rheem90+, but my Heat Pump I'm sure might play into this, and the desciption given on thier wiring was not clear. I HAVE called the installer who put this system in to do this but he has not responded after many calls. Thanks for any insight.

What is being used for thermostat control of the system?

With your model, you can wire the transformer to the EAC on the board for the power for the W/G and Cf, then the R and C goes to the R and C on the furnace board.

I'll would like to know what you got for t-stat and maybe we won't need to wire it up the above way.

thanks for the response Jay11J.
The t-stat is a Ruud HC-TST401MDMS.
Ques 1, when you state wiring transformer to EAC on the board for pwr to W/G & Cf, is that the Aprilaire transformer? & is the EAC a line voltage needing reduction to 24vac?
Ques 2, Will the configuration power the humidifier when either the heat pump or the furnace is operating?
Does a humidifier only operate when heating or is there ever a need before or after heating season? Again, many thanks for the help here.

The t-stat is a Ruud HC-TST401MDMS.
Ok, this t-stat don't have a build in humidistat for the humidifier. so we will have to wire it as said in my earlier post.

Ques 1, when you state wiring transformer to EAC on the board for pwr to W/G & Cf, is that the Aprilaire transformer? & is the EAC a line voltage needing reduction to 24vac?

Yes.

Ques 2, Will the configuration power the humidifier when either the heat pump or the furnace is operating?
Does a humidifier only operate when heating or is there ever a need before or after heating season?
The EAC will power up any time that the blower is running in heat pump mode, gas, fan "ON", or cooling.

So when comes spring when you won't need it anymore, shut off the humidistat.

I wired unit as you directed, checked & verified voltages at the humidistat, set the unit into test mode & all worked OK!
I wonder if you heard me yell YAHOO! from my crawlspace under my house in Michigan. Thanks again for your wise advice!! Beer 4U2 Greg

I wonder if you heard me yell YAHOO! from my crawlspace under my house in Michigan.
LOL No, I did not hear anything! But, I am sure your neighbors did!

Is your crawl space warm, some what warm? (Above freezing)



Thanks again for your wise advice!!

You are very welcome.. Glad to help.

my crawlspace is insulated, dry and kept above freezing
(40-45 deg) as I have a small supply register off the furnace to keep my floors from being cold. I just went down there to check the new humidifier (been working 16 hrs now) and all is good. Thanks!