FloAire FAV-M - Manual (Page 16)

16
SEQUENCE OF OPERATIONS
Description of Operation
Designed for indoor or outdoor installation, the Direct Fired Gas Heaters draw fresh outside air over a
gas-fired burner. The unit may be equipped to fire with natural or propane gas. Units are designed for
modulated firing of the burner, based on the discharge-air temperature or room temperature requirement.
Only outside air passes over the burner, with return air bypassing the burner.
Sequence of Operation – 80/20 Static Pressure Controller
1. With disconnect in ON position and the Summer-Off-Winter switch (SW-02) in WINTER position,
power is supplied to the damper motor (MT-02), if equipped
2. When damper motor approaches the OPEN position, the damper-end switch (SW-07) closes,
energizing blower-motor starter contactor (ST-01), powering blower motor (MT-01)
3. Power is supplied to the damper motor through the low-temperature limit control (TS-07), if equipped.
After a 5-min timed period, the low-temperature limit control shuts the unit off if discharge
temperatures do not reach minimum set points on the low-temperature limit control
4. The Photohelic Static Pressure Control (PS-05) modulates the return air and fresh air bypass
dampers (MT-03) to maintain the desired building pressure
5. The RCS (Re-Circulating Control System) will drive the unit into 100% fresh air if the temperature
drops below the Minimum Outdoor Set-Point (TS-10) or the Minimum Indoor Set-Point (TS-09) until
the minimum set-points are satisfied. There are several RCS systems see the chart below to see
your systems factory settings
6. When airflow switch (PS-01) is proven, the flame relay (RE-07) is energized through the high-
temperature limit control (TS-04), the optional low- and high-gas pressure switches (PS-03 & PS-04),
and the burner ON/OFF intake air stat (TS-06), if equipped. The pilot valve (VA-03) opens, and the
ignition transformer (TR-03) energizes
7. After the flame rod (SN-02) proves flame, the main valves (VA-01 & VA-02) open, and the ignition
transformer de-energizes
8. The temperature control systems amplifier (AM-01), monitors the discharge air sensor (TS-01) and
the remote discharge air set-point (TS-08), and modulates DC voltage to the modulating valve (VA-
05) to maintain discharge temperature
Sequence of Operation – 80/20 Manual Potentiometer
1. With disconnect in ON position and the Summer-Off-Winter switch (SW-02) in WINTER position,
power is supplied to the damper motor (MT-02), if equipped
2. When damper motor approaches the OPEN position, the damper-end switch (SW-07) closes,
energizing blower-motor starter contactor (ST-01), powering blower motor (MT-01)
3. Power is supplied to the damper motor through the low-temperature limit control (TS-07), if equipped.
After a 5-min timed period, the low-temperature limit control shuts the unit off if discharge
temperatures do not reach minimum set points on the low-temperature limit control
4. The Manual Potentiometer (PO-01) adjusts the return air and fresh air bypass dampers (MT-03) to
the desired building pressure
5. The RCS (Re-Circulating Control System) will drive the unit into 100% fresh air if the temperature
drops below the Minimum Outdoor Set-Point (TS-10) or the Minimum Indoor Set-Point (TS-09) until
the minimum set-points are satisfied. There are several RCS systems see the chart below to see
your systems factory settings