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It will be up to the user as to how many setpoints are entered. As a minimum, P03 must be entered
and P23 is the maximum. The more setpoints entered the better the interpolation between each set-
point and the smoother the firing rate curve.
Ending Commissioning Mode:
Pressing the C-MODE key ends the Commisioning Mode and saves all changes to the current pro-
file. The C-MODE LED will be extinguished. For commissioning mode, the last setpoint displayed
(above p03) will become the new high fire (100% modulation) setpoint. All previously entered set-
points above the point when commissioning is ended will be cleared if the user exits commissioning
above p02. If the PPC4000 has been commission above p03 and the user enters commissioning again
but exits before reaching p03, all previous values above p03 will not be cleared.
On exiting commission mode, the passcode will be disabled.
Modulation Rate vs Commissioning Points:
The firing rate curve (a.k.a. modulation rate) is automatically established by the installer during the
commissioning process of the burner. Setpoint p03 is the first position in AUTO and corresponds to
0% firing rate of the burner. If the unit is only commissioned to p03 no modulation rate other than
0% is possible. The final commissioned point (at least p04) is always the 100% firing rate position.
The modulation rate is based off a linear interpolation from the 0% to 100% master servo positions.
If no VFD is used in the current profile, the AIR servo is selected as the master servo.
If a VFD is selected for use in the active profile the first FUEL servo is the master servo.
Graph 1 depicts a typical air/fuel profile of a burner with 14 commissioned points and no VFD used
in the current profile so the AIR actuator is the master. Its p03 position is 12 degrees and the p13
position is 85 degrees. Therefore, the 50% position is ((85-12) X 50%) + 12 = 48.5 degrees. This
puts the 50% modulation rate close to the p10 position. The FUEL actuator at the 50% position will
be at approximately 30 degrees.
Graph 1 (no VFD):