Harman PC45 Installation & Operating Manual page 19

DISTRIBUTION
COMBUSTION
FEED
IGNITER
80°
Combustion Motor Speed Control
Low draft only set point. The small straight screwdriver
slot is plastic; therefore, the unit can be adjusted while
75°
in operation.
5
low draft voltage Adjustment
These units are pre-tested at the factory with exactly 120
4
70°
VAC, 60 Hz. They are checked and adjusted for firebox
tightness, gasket leakage, motor operation and ignitor
operation. The PC 45 is then factory set at a mid-point
adjustment and in most cases will not need any adjustments.
3
NOTE: The factory low draft setting may not be correct
65°
for the unit's permanent installation conditions.
The control board on the PC45 is equipped with a low draft
adjustment port. Located on the control face just to the right
60°
of the igniter light. This voltage adjustment is provided to allow
the unit to be adjusted for the household voltage where the
unit is going to be in permanent operation. NOTE: The line
voltage varies from area to area and often home to home.
The low draft voltage should be adjusted to achieve the most
( WARNING ) HIGH VOLTAGE
efficient burn on low burn or "maintenance". This voltage
Disconnect power before opening cover.
adjustment allows the installer to change the low voltage set
point approximately 10 volts. This adjustment should be done
by the installer during set up because a draft meter reading
is required to insure proper set up.
If the unit is not adjusted properly, it does not cause a safety
concern. If the unit is adjusted too high, only efficiency is lost.
If the unit is adjusted too low, the low draft pressure switch
will not allow the feeder motor or the igniter to operate.
A simple draft test should be performed after completing the
flue pipe installation. To record the results for future reference:
19 pC 45 Corn/pellet Stove
low draft voltage Adjustment
BLOWER
BLOWER
MOTOR
85°
90°
6
Fig. 27
7
OFF
1
2
50°
55°
AUTO
IGNITER
MANUAL
draft meter bolt
hole location
On a PC 45 the draft
hole is under the left
rear corner of the
firebox.
Fig. 28
draft Test Instructions
1. Attach a draft meter capable of reading up to a minimum
of 0.5 inches of water column (W.C.).
2. Plug the unit's power cord into a 120 VAC, 60 Hz grounded
outlet.
3. Close the hopper lid, front view door, and the ash pan
access door. Neither fuel or a fire are required for this test.
4. With the mode selector in the "OFF" position, turn the feed
adjuster to "TEST".
5. Record the high draft_____in W.C. (Normal is -.35 to -.55)
The control will be on the High Draft for a minute.
6. After 1 minute is up, the combustion motor will go down to
low draft and the distribution blower will go on high. Allow
approximately 15 seconds to pass for the combustion
motor to slow before checking the low draft.
7. If the low draft is between -.25 and -.35, record the reading
_____ in W.C. If the reading is higher, slowly turn the
set screw counter-clockwise until the draft lowers. If the
reading is lower, very slowly turn the set screw clockwise
until the draft increases.
NOTE: In some cases, the draft may not go as low as
-.25 to -.35 even with the set screw completely counter-
clockwise. This is not a problem. vertical runs of venting
may add natural draft.
If the draft reading does not drop at all when the test
mode switches from high to low, be sure to check for
restrictions in the appliance air intake.
TEST
3-90-02686R29_05/14