Greenheck Fan Part #470655 manual Operation - Electrical Sequence With 7-DayTimer

Operation - Electrical Sequence With 7-Day Timer

1.Switch (S2) in Summer Mode

•Power passes through N.C. field-supplied fire contact (FSC)

•Power passes through terminal G

•Power passes through N.C. contact on supply starter overload (ST1 OL), which is closed if the supply fan has not overloaded

•Power passes through N.C contact on optional freeze protection timer (RT4), which is closed if the temperature has remained above the set point.

•Power passes to and energizes optional inlet damper (D1), which opens

•Power passes to and energizes fan relay (RF)

•Power passes to N.O. contact on fan relay (RF), which closes once the fan relay (RF) is activated

•Power passes to and energizes supply fan starter

(ST1)

•N.O. contact on supply fan starter (ST1) is energized and closed

•Supply fan (M1) starts

2.Switch (S2) in Winter Mode

•If space temperature is less than the daytime temperature setting, the N.O. contact on the temperature sensor (TS1) closes and power passes to the timer (TC1). If the timer (TC1) is on, power passes through N.C. field-supplied fire contact (FSC). If the timer (TC1) is off, but the space temperature is less than the nighttime temperature setting, the N.O. contact on the temperature sensor (TS2) closes and power passes through N.C. field- supplied fire contact (FSC)

•Power passes through terminal W1 and then energizes the space heat relay (RS)

•Power passes through N.O. contact on the space heat relay (RS), which is energized and closed

•Power passes through terminal G

•Power passes through N.C. contact on supply starter overload (ST1 OL), which is closed if the supply fan has not overloaded

•Power passes through N.C. contact on optional freeze protection timer (RT4), which is closed if the temperature has remained above the set point

•Power passes to and energizes optional inlet damper (D1), which opens

•Power passes to and energizes fan relay (RF)

•Power passes to N.O. contact on fan relay (RF), which closes once the fan relay (RF) is activated

•Power passes to and energizes supply fan starter

(ST1)

•N.O. contact on supply fan starter (ST1) is energized and closed

•Supply fan (M1) starts

•Power passes through N.O. contact on fan relay

(RF), which is energized and closed

•Power passes to and energizes the heat relay (RH)

•Power passes through N.O. contact on heat relay

(RH), which is energized and closed

•Power passes to and energizes terminal 5 on the

Flame Safeguard (FSG)

•Power passes through N.C. contact on high temperature limit control (HLC1), which remains closed if the temperature has remained below the HLC1 set point

•Power passes through optional N.C. and N.O. high and low gas pressure contacts (PS4 and PS3), which are both closed if the gas pressure is within the set range

•Power passes to terminal 6 on the Flame Safeguard

(FSG)

•Flame Safeguard (FSG) begins direct gas burner sequence (See Flame Safeguard Sequence)

3.Flame Safeguard (FSG) Sequence

•Verifies proper airflow with airflow switch (PS2)

•Verifies no flame is present at burner

•Initiates 10 second prepurge

•Sends power to open pilot valve (V1) and energizes the spark generator (SG) (clicking of the spark generator may be heard)

•Energizes spark generator for up to 10 seconds to light pilot and confirm flame

•Powers the main gas valve (V2) open

•Shuts down spark generator (SG)

•Continuously monitors the flame and airflow

•Performs self-diagnostic check every four seconds

16 DGX Industrial Space Heating

®