Harman Stove Company PC 45 manual Low Draft Voltage Adjustment

Low Draft Voltage Adjustment

Combustion Motor

Speed Control

Low draft only set point.

The small straight screwdriver slot is plastic; therefore, the unit can be adjusted while in operation.

Fig.29

Low Draft Voltage Adjustment

Draft Meter bolt hole location

On a PC 45 the draft hole is under the left rear corner of the firebox.

Fig. 30

These units are pre-tested at the factory with exactly 120 Volts A.C., 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. NOTE: The factory low draft setting may not be correct for the units 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 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 efficient burn on low burn or "maintenance". This voltage 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 effiency 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:

1.Plug unit into a 120VAC, 60 HZ outlet.

2.Close the hopper lid, front view door, and the ash pan access door. Neither fuel or a fire are required for this test.

3.With the mode selector in the "OFF" position, turn the feed adjuster to "TEST".

4.Record the high draft_____in W.C. (Normal is -.35 to -.55) The control will be on the High Draft for a total of 2 minutes.

5.After 2 minutes 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.

6.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: The test mode alternates from high to low draft every 60 seconds. If more time is needed for draft adjustment, wait until the next low draft cycle.

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.

18 PC 45 Corn/Pellet Stove