Make-Up Air Installation Manual

01/17/2013 EI902

2. GROUNDING - Route and install the appropriate size ground conductor between the ground lug labeled

"GROUND" and building service entrance panel ground buss. This must be a conductor sized according

to the total amp rating of the appropriate model. Conduit is not a adequate ground conductor.

3. 24 VOLT SOURCE – Connect the system 24v transformer to “R” and “C”. Typically this is from the

Fan Center. If this is tied in with an existing thermostat system and furnace air handler, do not add a

separate transformer for this unit. If this is a stand alone makeup air unit, you will need a 24-volt

transformer to operate this unit.

4. THERMOSTAT OR TURN-ON CONTROL - This unit is activated (elements turn on and off) when a

contact is applied to the terminal block “Y” and “R”. Using either a roomstat thermostat W connection,

or an external relay contact (relating to blower operation); close “Y” to “R”for basic on/off operation.

Comment: Electro Industries stocks pressure differential (set at 0.2 static) airflow detecting turn-

on switch (P/N 5009) or current sensing switch with adjustable detection (P/N WF-ISW). If these

“turn-on” devices would be a help in your installation, call factory.

Duct Sensor

This unit is equipped with a remote temperature-sensing probe. This is a solid state probe (actually mini-micro

computer chip at the end of the probe), handle with care.

Suggested installation is in the main warm air stream approximately 20 to 24 airflow inches away from the

electric element. Simply drill a ½” hole in the duct, insert probe, and screw in place.

Comment: The sensor tip within the tube should be at the end of the tube or slightly extending beyond

the tube. If this is not the case, very carefully push the cable (do not grab the sensor tip with pliers) until

the sensor tip can effectively sample the warm air.

This duct sensor has a 6-wire cable. It should be connected to the Red, ST, and COM screw terminals. The “OT”

screw terminal is not used for this product application.

WARNING - If the black and red sensor wires are crossed or incorrectly installed at the terminal

block and power is turned on, burnout damage can result within the sensor probe.