Use and Care Manual

18
6-583.12
CONTROL OPERATING SEQUENCE / UNIT COMPONENTS
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
all ready 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 1 hour wait before
ignition is tried again.
CONTROL OPERATING SEQUENCE
Figure 18.1 - Major Gas, Electrical Service, Safety and Other Components
1. Power Exhauster
2. Pressure Switch
3. Integrated Direct Spark Control Board
4. Combination Gas Control
5. Control Transformer
6. Flame Sensor (hidden)
7. Flame Rollout Switch
8. Auto Reset Limit Control (hidden)
9. Direct Spark Igniter (hidden)
10. Manual Reset Control (hidden,
propeller 100-125 only)
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Table 18.2 - Propeller Model HD Performance
Table 18.1 - Control Options
Table 18.3 - Blower Model HDB Performance
Model HD Sizes
30 45 60 75 100 125
Btu/Hr Input 30,000 45,000 60,000 75,000 100,000 125,000
Btu/Hr Output 24,600 36,900 49,200 61,500 82,000 102,500
Entering Airow (CFM) @ 70°F 505 720 990 1160 1490 1980
Outlet Velocity (FPM) 523 725 653 769 565 747
Air Temp. Rise (°F) 44 46 45 48 50 47
Max. Mounting Height (Ft.) 10 10 12 14 12 16
Heat Throw (Ft.)
(@ Max Mtg Ht.)
25 27 36 38 42 56
Motor Type SP SP PSC PSC SP PSC
Motor HP 1/15 1/15 1/12 1/12 1/6 1/8
Motor RPM 1550 1550 1625 1625 1050 1625
Model HDB Sizes
60 75 100 125
Btu/Hr Input 
60,000 75,000 100,000 125,000
Btu/Hr Output 
49,200 61,500 82,000 102,500
Entering Airow Range (CFM) 635-1111 794-1389 1140-2116 1235-2058
Outlet Velocity (FPM) 437-726 546-908 443-781 488-773
Air Temp. Rise (°F) 40-70 40-70 35-65 45-75
Max. Mounting Height (Ft.) 
7-13 7-16 8-19 8-17
Heat Throw (Ft.)
(@ Max Mtg Ht.) 
20-45 24-57 27-68 27-59
Motor Type 
P.S.C. P.S.C. P.S.C. P.S.C.
Motor HP 1/4 1/3 1/2 1/2
Motor RPM Max 1100 Max 1100 Max 1100 Max 1100
Control Description
Control Service Thermostat Type of Model
Code No. Voltage Voltage Gas Size
Single-Stage, Direct Spark Ignition, 100% Shut-Off with Continuous Retry 11 115V 24V Natural 30-125
- Utilizes a single-stage combination gas control with ignition control. Gas is lit with a
direct spark igniter on call for heat. 21 115V 24V Propane 30-125
Two-Stage, Direct Spark Ignition, 100% Shut-Off with Continuous Retry 12 115V 24V Natural 75-125
- 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
22 115V 24V Propane 75-125
igniter on call for heat.
 Ratings shown are for elevations up to 2,000 feet. For elevations above 2,000 feet,
ratings should be reduced at the rate of 4% for each 1,000 feet above sea level. (In
Canada see rating plate.) Reduction of ratings requires use of a high altitude kit.
 Data taken at 55°F air temperature rise. At 65°F ambient and unit fired at full-rated
input. Mounting height as measured from bottom of unit, and without deflector hoods.