Greenheck ERCH Installation, Operation And Maintenance Manual page 25

Optional Component Overview
Optional Exhaust Fan Only Power
The exhaust fan will have a dedicated power circuit
where in the case of a power outage, the exhaust fan
will still run. A phase monitor will detect an outage or
power loss and open the contact, disconnecting all
power to the unit and controller. An external signal will
need to be sent to a relay to power the exhaust fan,
enabling the fan to run at a maximum speed. This
sequence is NOT to be used for high temperature
exhaust applications.
Airflow Monitor
A factory-wired, mounted, and powered airflow
monitoring system is provided in the outdoor and/or
exhaust air streams. The airflow control system offers
the following functionality:
• Display of outdoor and/or exhaust airflow rate in
actual cubic feet per minute (CFM) or actual liters per
second (LPS) on a 16 character LCD display.
• Two configurable analog outputs for transmitting
outdoor and/or exhaust airflow rate, outdoor air
temperature, or a proportional-integral-derivative
(PID) control signal based on an outdoor airflow set
point.
• A configurable digital output that operates based on
an airflow set point or range.
Operation
Outdoor and/or exhaust airflow monitoring is
accomplished using two thermal dispersion sensors
that accurately measure airflow velocity down to zero
feet per minute (fpm). The airflow controller takes the
average measurement for two sensor configurations,
and determines the outdoor airflow rate based on the
effective intake area. Field calibration of the outdoor
airflow monitoring device determines the effective intake
area of the unit.
Refer to GreenTrol® Automation Inc. GF-N2211
technical data sheet for further detail.
IMPORTANT
For the airflow monitoring device to perform as
intended, field calibration is required. Calibration of
the airflow monitoring device requires an independent
measurement of airflow and should be performed
when the system undergoes test and balance.
®
Smoke Detector
The Hochiki America DH-98 duct
smoke detector provides early
detection of smoke and products of
combustion present in air moving
through HVAC duct systems. The
DH-98-P is designed to prevent
the recirculation of smoke in areas
by the air handling systems, fans,
and blowers. Complete systems may be shut down
in the event of smoke detection. The Hochiki America
DH-98-P operate on 115 VAC, 24 VAC and 24 VDC.
The DH-98-P is designed and built to meet all local
requirements, as well as the NFPA regulations regarding
duct smoke detectors. Output terminals are provided
for remote accessories such as a horn, strobe, remote
status indicators and reset key switches or push
buttons.
Refer to Hochiki America DH-98-P installation
instructions for further detail.
Energy Recovery Ventilator with Heating and Cooling General Description - NOT model specific 25