Unit Components - Modine HDS Manuel D'installation

CONTROL OPERATING SEQUENCE / UNIT COMPONENTS
CONTROL OPERATING SEQUENCE
Upon a call for heat from the thermostat, power is supplied to
the power exhauster motor. The unit will go through a purge
period and then the direct spark igniter will be energized. At the
same time, the main valve in the combination control valve will
open to allow gas to flow to the burners. If the fan motor has not
Figure 18.1 - Major Gas, Electrical Service, Safety and Other Components
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1. Power Exhauster
2. Pressure Switch
3. Integrated Direct Spark Control Board
4. Combination Gas Control
Figure 18.2 - Unit Heater Rear View
Mounting Brackets
Fingerproof Fanguard
Fan Motor
Vent Pipe Connection Electrical Access
Holes
Table 18.1 - Control Options
Single-Stage, Direct Spark Ignition, 100% Shut-Off with Continuous Retry
- Utilizes a single-stage combination gas control with ignition control.
Gas is lit with a direct spark igniter on call for heat.
Two-Stage, Direct Spark Ignition, 100% Shut-Off with Continuous Retry
- Utilizes a two-stage combination gas control with built-in ignition control.
Firing rate is 100% and 50% of full rated input. Gas is lit with a direct spark
igniter on call for heat.
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5. Control Transformer
6. Flame Sensor (hidden)
7. Flame Rollout Switch
8. Auto Reset Limit Control (hidden)
Gas Pipe
Access Panel with
Combustion Air Inlet
Lighting / Operating
Pipe Connection
Instructions
Control Description
already started it will start shortly. If a flame is not sensed for
any reason the main valve will close and there will be a short
purge period before ignition is tried again. If the flame is not
sensed after 4 tries there will be at least a one hour wait before
ignition is tried again.
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Flame
Sight Glass
Control Service
Code No. Voltage
11 115V
21 115V
12 115V
22 115V
6-584.11
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9. Direct Spark Igniter (hidden)
10. Manual Reset Control (hidden,
propeller 100-125 only)
Thermostat Type of Model
Voltage Gas Size
24V natural 30-125
24V propane 30-125
24V natural 75-125
24V propane 75-125