39UH-PRC002-EN
Electric
Power
Separated Combustion Units
Single-Stage Control
With power applied to the unit:
1
The thermostat calls for heat.
2
The pressure switch measures the
pressure differential between the air inlet
and exhaust vent systems. If the
differential is correct, the intermittent
pilot ignition is energized. CAUTION: THE
PRESSURE SWITCH MUST NOT BE
BYPASSED. THE UNIT MUST NOT BE
FIRED UNLESS THE FLUE VENT FAN IS
OPERATING.
3
When the pressure switch is closed, the
power venter motor is energized.
4
The pilot valve opens.
5
The ignitor sparks continuously to ignite
the pilot.
6
The sensor proves pilot ignition and
shuts off the ignitor.
7
With the pilot lit, the main gas valve
opens.
8
Main burners are lit at 100 percent of the
unit’s rated input.
9
The fan time delay relay allows the
heater to come up to operating
temperature. At this time, the fan time
delay relay closes and activates the fan
motor.
10
The unit continues to fire until the
thermostat is satisfied and no longer
calls for heat.
11
The main and pilot valve close.
12
The pressure switch opens and
deactivates the flue vent fan.
13
The fan time delay relay remains closed,
keeping the fan operating to dissipate
residual heat from the heat exchanger. At
this time, the fan time delay relay opens
and deactivates the fan motor.
• Caution - Disconnect power before
servicing.
• Unit must be grounded.
• Use copper conductors only.
• If any of the original wire as supplied
with the appliance must be replaced, it
must be replaced with wiring material
having a temperature rating of at least
125°C.
• Hi-limit and blocked vent (spill) wires
minimum 200°C.
• Refer to installation instructions for
venting, gas piping and start-up
procedures.
• - - - Indicates Field Wiring.
• ___ Indicates Factory Wiring.
L2
L1
DISCONNECT
LINE IN 115/1/60
L1
FAN TIME DELAY
L2
8
BLOWER/FAN
MOTOR
MTR
DRAFTOR
MOTOR
MTR
K5
BLACK
BLACK
LINE TO
24V XFORMER
50 VA
L2
8
12
24
VOLTS
2
SUMMER/WINTER SWITCH
W
S
L1
FAN TIME DELAY
DL
DRAFTOR ONE
K5
MV SOL.
PV SOL.
58600 IGNITOR
MV
MV/PV
PV
GND
24V (GND)
24V (HOT)
SPARK
PRESS. SW.
IGN
1
2
V
W1
R1
DL
HIGH LIMIT 1
1
3
2
1
W1
DL
V
2
T/D STAT
R
W/B
1
