Page 21 of 36
7B. WIRING AND CONNECTIONS
This area is used to fi ne tune actual operating conditions by manually setting DIALS to match actual
appliance or operational condition to provide fresh air ventilation all year round to meet ASHRAE 62.2
Ventilation Standards while providing energy conservation, better indoor air quality and keeping
comfort in mind. Refer to TABLE 1 for Air Flow Dial ranges and Factory Settings.
The fi rst three dial settings (CFM Continuous, CFM Cool Vent and CFM Heat Vent) on the FAVC
are used for computing the continuous ventilation run time and dwell time based on ASHRAE 62.2
Standard. The cycle rate is fi xed at 30 minutes. Refer to Figure 2 for ventilation only required dials.
Adjust the setting on the FAVC for the CFM Continuous dial to match the continuous ventilation rate
for your dwelling per VENTILATION SETTINGS section, starting on page 5.
The CFM Continuous
rate is initially factory set at 100 CFM.
The
Cool Vent and Heat Vent
dial settings allows for two different settings if the air handler is equipped
with an ECM blower that may operate at different fan speeds for cooling and for heating modes.
If the system is a heat pump, the FAVC will automatically detect if the system is operating in cooling
or heating based on the outdoor air temperature and the return air temperature. Each heating and
cooling cycle is monitored; minimum and maximum temperatures are also recorded to anticipate
the next call for heating or cooling. Conventional systems or heat pumps with auxiliary heat, the W
terminal will indicate if the system is in heating mode of operation.
The CFM Cool Vent and CFM Heat
Vent rates are initially factory set at 400 CFM each.
Refer to Wiring Diagrams 1 and 2 for basic ventilation wire requirements using Fresh Air Damper
or HRV/ERV devices. Refer to wiring diagrams 3 and 4 when adding optional appliance monitoring
and/or control features.
7Bi. Ventilation Control Connectors
The FAVC has two isolated outputs for control of a fresh air damper and a remote relay to
control an exhaust fan (auxiliary fan for balanced ventilation or a bath fan). The Vent and
Exhaust Fan terminal block is in the VENT AND EXHAUST VENTILATION CONTROL CONNECTION
area of the FAVC as shown in Figure 1 and Figure 21. The terminals for the ventilation
damper are labeled with a V; and the terminals for the exhaust fan are labeled with an E. Both sets of
terminals are compatible with all types of ERV/HRV systems that use dry contact or DC signals. The
V terminals can be used to activate an ERV/HRV unit if placed into intermittent fan operation. Some
ERV/HRV units can be confi gured to operate as two speed where the low speed will run continuously
and the high speed is activated by dry contacts. If the fl ow rate of the low speed operation is measured,
it can be subtracted from the required continuous cfm rate on the primary control. The high-speed
rating can be used for both Cool and Heat vent CFM values if a fresh air damper is not used. Both,
the V and E terminals are isolated from the 24 VAC supply (dry contact form), one terminal of the
pair must be connected to the R (24VAC) power side of the supply transformer to control the fresh air
damper or the remote relay to operate a fan. Both V and E terminals will be active during
ventilation calls.
FIGURE 21: Vent and Exhaust Control Connections (Rotated 90°)
WARNING: Under no circumstances shall line voltage be wired to these terminals. This product
is rated for Class 2 low voltage use. Ratings: 24VAC (3A max load). Dry
contact compliant, and suitable for up to 24VDC (3A max load).
P/N 780100700 07/18 Rev F
