Detroit Radiant Products Company QTD Series - Manual (Page 33)

QTD Series
33
3.0 Installation • Electrical Requirements • Internal Wiring Diagrams
Figure 3.24 • Internal Ladder Wiring Diagram
120V/24V
TRANSF.
BLOWER
MOTOR
FAN
RELAY
DUAL POLE
RELAY
24VAC
CONTROL WIRES
PRESSURE
SWITCH
TWO-STAGE
GAS VALVE
FLAME SENSOR &
SPARK IGNITOR
FLAME SENSOR &
SPARK IGNITOR
HIGH
FIRE
LOW
FIRE
HIGH-FIRE
RELAY
LINE VOLTAGE
120VAC 60Hz
NEUTRAL
DPDT SWITCH
(24V I/O)
BK
G
1
2
3
4
V1
V2
NC
W (24V IN)
S1
S2
(24V IN) R
GND
GND
CIRCUIT BOARD
DIAGNOSTIC
LIGHT
O O
PR
PR
O
BL
R
BL
BK BK
BK
W
O
Y
O
BL
Y
O
Y
GY
BK BK
BL
BL
R
BK
W
Y
Y
Y
BL
GY