My furnace terminals pic (note the HUM terminal with 0.5A @ 24VAC
Honeywell EIM pic
I purchased Aprilaire 700 automatic that came with an outdoor sensor humidistat and separate 24vac transformer.
I also have a Honeywell EIM, Prestige IAQ 2.0 Thermostat with ourdoor air/humidity sensor that I plan to install today.
What I want to be able to do is use the EIM, the Honeywell outdoor sensor and the Prestige IAQ to control the humidifier and not use the Aprilaire Humidistat and the outdoor sensor, can I do that?
Lets assume that the Honeywell system is wired to the furnace and is working correctly.
Now in order to add the humidifier, do I need to use a separate transformer?
What is the reason to use a separate transformer, is it only if you use the Aprilaire humidistat and the aprilare outdoor sensor because the outdoor sensor requires constant power to figure out what is the outdoor humidity even when the humidifier isn't running) or is there another reason?
I am thinking of running the wires as following:
One of the brown wires to the UI1 terminal on the EIM
Other brown wire to the Comm24vac terminal on the furnace
And run a wire from the HUM terminal on the furnace to the UI2 terminal on the EIM
Is that the best/proper way to wire in my case?