Wiring - Modine Manufacturing HD Installation And Service Manual

UNIT WIRING
Table 18.1
Troubleshooting (continued)
TROUBLE POSSIBLE CAUSE
Unit starts but does 1. Main gas is off.
not ignite. 2. Air in gas line.
3. Main or manifold gas pressure
4. Check gas valve switch.
Unit goes through cycle 1. Reversed main power polarity
but the burners go out in 2. Unit not grounded
less then 10 seconds 3. Flame not sensed
Air circulating fan 1. Loose connections
inoperable 2. Defective Fan time delay relay
3. Defective fan motor
Wiring Diagram Selection
Since internal or factory wiring may vary depending on
controls manufacturer, the wiring diagrams must be selected
with the series identity number when installing, servicing, or
troubleshooting a unit heater control system. Wiring diagrams
that follow are for units with the corresponding series identity
number that may be found in the 5
Figure 18.1
Unit Heater Wiring Diagram (Series 103)
Wiring Legend
Line 24V
Factory
Internal Component Wiring
Field
Wire Nut
Flame
Sensor
W
Hot
Surface
Igniter
BK
Plug
BK
C2
Power BK BK
Exhaust
Motor
W
W
Plug
Honeywell
Combination
Gas Control
GND
Y
Y
R R
Press Limit
Switch
Control
Note to installer:
All wiring must comply with national
electric code and all local codes.
All components must agree with Failure to wire this unit according
their respective power source. to this wiring diagram may result
in injury to the installer or user.
Use 105°C wire for replacements. For deviations contact the factory.
Verify the power source and the
unit polarity.
18
th through the 7 th digits of
Fan
P
Motor
BK BK
GND
W
1 2 3 4
BK
1 2
3 4
W
O
C1
R
4 8
R
3 7
6
2
BL
1 5
4 1
2
5
6 3
P5
24 VAC
R
R
Terminal
Board
W
R
R R
Flame
Flame
Rollout
Rollout
Switch
Switch
Terminal Block
G
R W
(HDS ONLY)
Caution
Low Volt
Therm
(By
Others)
Single-Stage, Hot Surface Ignition, 100% Shut-Off, Multiple Retry with Auto Reset
5H79409B1 REV B
from Lockout, Single-Phase.
POSSIBLE REMEDY
1. Open manual gas valve .
2. Purge gas line.
3. Set gas pressures per manual instructions
4. Set gas valve switch to "ON" position
1. Black wire - HOT, White wire - NEUTRAL, Green wire - Ground
2. Ground unit and verify quality of ground connection.
3. Check flame sense probe and connection
1. Check all connections
2. Check fan time delay relay
3. Check fan motor
the serial number. For example, a unit with the serial number
"30011033605-0981" has the 5
as shown underlined above. To use the following diagram the
unit series ID must be 103.
115V/60Hz/1Ø Power
Circuit Breaker (By Others)
GR(G)
BK
L2(W)
L1(BK)
W BK
BK
COM
TR1
24VAC
G2
TR2
P5-5
G
P5-6
W BK
COM
120V
R
XFMR Y
24V
GND
6-576.5
th
through the 7
L1 L2
115V/60Hz/1Ø Power
Circuit Breaker
Shown
(By Others)
BK
TD1 Relay
Contact
BK Fan
BK
L1 L1 TR1 TR2
Motor
Power
Exhaust
Motor
BK W
BK
P5-1 C3-2 C3-1 C3-3
Combination Gas Control
C2-1 C2-3
W
BK
Hot Surface
Igniter
BK W
H H
115V
Xfmr
24V
R Y
Therm
t°
R G
W
P5-2
R
O
R
C1-8
C1-7 C1-4
Combination Gas Control
C2-4 C1-2 C1-3 C1-3 C1-1
P Y Y R
Flame
Flame
Pressure
Limit Rollout
Sensor
Switch
Control Switch Switch
R R
Indicates Terminal Board Connection
Indicates Gas Valve Connection
th
digits as 103
GND
W
BK
L2
W
W
C3-4 P5-4
TD1
G2
COM
Relay
P5-3
BL
C1-6
C1-5 C1-5
R
Flame
Rollout