Product Overview

page 2 of 4
1. Install the HHSC+ Ventilation Control, and low-voltage wiring tothe Makeup Air
Sensor: Follow the instructions for installation included with the HHSC+ and
refer to Wiring Diagrams below to determine the desired wiring con guration.
Avoid routing the low-voltage wiring near line-voltage circuits and high-
current devices.
Caution: Before beginning the installation, disconnect electrical power to
the exhausting device and the HVAC system, and verify that there is no
voltage from terminal R to C on the HHSC+.
Warning: Follow all applicable wiring codes applying to the installation
of line voltage branch circuits and low voltage, low current signal wiring.
Installation must be performed or inspected by a licensed electrician or
authority having jurisdiction over electrical installations.
2. Install the Makeup Air Sensor: NOTE: It is recommended that the Makeup
Air Sensor be installed on a dedicated branch circuit feeding only the exhausting
device for which makeup air is to be provided. If any other devices are served
by the branch circuit, the sum of their current draws must be signi cantly less
than the current draw of the exhausting device when operating in a manner
requiring makeup air.
a. Remove the cover from the Makeup Air Sensor, and install the sensor as an
electrical junction box on the dedicated branch circuit, in an acceptable and
accessible location.
Caution: the junction box must be properly connected to an earth ground
using the provided grounding connection!
INSTALLATION
Figure 1
Figure 2
b. Inside the Sensor junction box, select either the hot leg conductor wire
(typically black) or neutral leg conductor wire (typically white) serving the
exhausting appliance. Note: it is preferable to separate a conductor carrying
power to the fan motor only, if possible, while meeting all applicable wiring codes.
c. Pass the selected conductor through the large hole in the Makeup Air Sensor switch (see Figure 1 for
example of wiring).
d. Complete any required wiring connections within the junction box, and install the box cover.
3. Connect the low-voltage wiring from the Makeup Air Sensor low-voltage terminals (see Figure 2) to HHSC+
Ventilation Control AUX-IN & R terminals, and/or E-Sensor or T-Sensor Damper Control, if installed: Refer to
E-Sensor/T-Sensor Installation and Operation Instructions for details pertaining to system con guration selection
and speci c operation of the system.
4. Adjust the Makeup Air Sensor:
a. Restore power to the exhausting device, and operate the device for which makeup air is desired or required.
If the device is multi-speed, operate on a speed rated at or above the air  ow amount for which makeup air is
desired (typically 400 cubic feet/minute, or cfm). The indicator LED lamps on the Sensor should glow either green
or red.
b. Turn on any equipment or appliances that may be served by the branch circuit feeding the exhausting appliance.
c. Turn the adjusting screw on the Sensor to the left until only the green “O ” LED lamp glows.
d. Turn the adjusting screw to the right just until the red “On” LED lamp glows. Turn the screw slightly more to
ensure operation under lowered-voltage conditions.
5. Restore power to the HVAC system: The HHSC+ ventilation control should activate the FAD damper to open, and
activate the HVAC central fan if it is not being caused to run by the thermostat. This will continue as long as the
exhausting device is operated.
P/N 46685800 Rev A 04/17