Field Controls HHSC+, User Manual, Page: 14 / 20

page 14
SAVING THE SETUP
While in the Menu = Continue/Select = Save & Exit window, press SELECT to save the setup settings, exit
to the normal operation display window and begin normal operation, or MENU to continue with viewing the
available menu items and settings.
If no buttons are pushed for three minutes, any changes to settings will be automatically saved and the
HHSC+ will return to normal operation with any changes to settings taking effect immediately.
NORMAL OPERATION DISPLAY AND LED STATUS
Under normal operation, the status LED will glow steady green and the HHSC+ display will show the current
time and date on the upper display line. On the lower display line, “FAN ON” will be displayed if the HVAC
fan is on (from either thermostat command or HHSC+ program), and “VENT ON” if the FAD vent damper
is open.
The status LED will glow steady red, and the display will show an alert message, if action is required for
service or maintenance:
• UV lamp replacement: the selected period for replacing UVC germicidal lamp(s) has expired.
Replace the lamp(s) and reset the timer by following the instruction on the display.
• HVAC filter replacement: the selected period for replacing the HVAC system filter(s) has expired.
Replace the filter(s) and reset the timer by following the instruction on the display.
• Damper Malfunction: the HHSC+ has detected an FAD fresh air damper malfunction (if enabled).
Service is required to correct the malfunction; the alert will automatically reset when the malfunction is
corrected, or the Damper Monitor feature is disabled.
• The internal backup battery has become weak and is in need of replacement.
OPERATION
INDEPENDENT OPERATION
The HHSC+ will command the HVAC fan to operate periodically for a specific length of time, as governed
by the chosen Fan Cycle Period and Circulate % settings, for a length of time (in minutes) equal to
Fan On time = Fan Cycle Period setting (minutes) X Circulate % ÷ 100
Also, the HHSC+ will command the FAD vent damper to open, and the Auxiliary Output terminals will be
energized (24 VAC), at the beginning of each fan cycle, for a length of time (in minutes) equal to
Vent On time = Fan Cycle Period setting (minutes) X Ventilate % ÷ 100
If the Damper Monitor feature is enabled, the Auxiliary Output terminals will not energize until the FAD
damper opens fully and communicates back to the HHSC+ by energizing the VS-In terminal via the FAD
pigtail’s yellow wire; otherwise, the Auxiliary Output will be energized immediately. The FAD damper and
Auxiliary Output will not be activated for a longer time than the HVAC fan will be commanded to run, but
they may be activated for a shorter time.
At the expiration of the Fan On time, the HHSC+ will end the commands to the FAD damper, the HVAC
fan, and the Auxiliary Output. The HHSC+ will then remain idle for the remainder of the Fan Cycle Period,
when it will begin a new cycle, or the system thermostat calls for action, as described below.