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Programming
P-7: (Reserved for future use.)
P-8: (Reserved for future use.)
P-9: Display Brightness Control
The display brightness can be adjusted from 4 to 18, with 4 being the dimmest and 18 the brightest. Typically a dark cabin will
require a setting of 4 or 5. A very bright cabin will require a setting of 12 to 18.
P-10: Fahrenheit or Celsius Selection
The default setting is °F. Select °C for Celsius. (Celsius readings are displayed in tenths, for example 22.2°).
P-11: (Reserved for future use.)
P-12: Reverse Automatic Fan Speeds During Heating
The automatic fan speeds can be reversed during Heat Mode to improve heat output in cooler climates. The fan will speed up
as the set point is approached. Lowering the fan speed when the cabin is cold helps raise supply temperature. The fan switches
to low speed when the set point is satisfied and the water valve cycles off. The fan can be programmed to operate the same as
in cooling by programming P-12 "nor" which represents normal fan operation during reverse-cycle heating.
P-13: Reverse-Cycle or Electric Heat
Units may be equipped with an electric heater which is used to heat an individual cabin when the chiller system is in cooling
mode. Set to "ELE" for the electric heat option or "nor" to disable.
•
For software revision A13 and older: When this parameter is programmed for electric heat, only the electric-heat
relay located toward the middle of the circuit board is energized during a heating cycle (see "Sample Wiring Diagrams"
on page 16).
•
For software revision A15 and newer: When programmed for electric heat, both the electric-heater relay and the
valve relay are energized. This change supports newer circuit board revisions without the electric-heater relay.
Therefore, circuit boards that do not have electric-heater relays require a display with software revision A15 or newer
to properly energize the compressor relay. Also, when using this configuration the electric heater L-1 connection must
be connected to the COMP L-1 terminal on the AH-Passport I/O or U-board (see "Sample Wiring Diagrams" on
page 16). Please consult with Dometic Customer Service or with an authorized service technician for assistance.
P-14: Fan Motor Selection
The "SC" (Split Capacitor) default setting is correct for air handlers with high-velocity blowers. Only change the setting to "SP" if
your unit has a Shaded Pole fan motor, recognizable by a blower-motor overhang. (The SC motor of a high-velocity unit is inside
the blower, and the unit has "VTD" or "HV" in the model number.)
P-15: Reset Memorized Defaults
To reset all programming parameters set this parameter to "rSt". This restores all programmable parameters to the last saved
default values. Once new values are entered and memorized the factory defaults are overwritten, and the new parameters
become the default values. To restore the original factory default parameters manually, refer to Table 2, page 10.
P-16: Hydronic Water Valve Forced Open
This parameter opens the water valve to bleed air from the system. "OPn" forces the valve open for 4 hours while the AH-Elite
control is turned off. If the control is turned on or if AC power is interrupted to the control's electric box during this 4-hour period,
this valve override feature is canceled. You can return the valve to normal operation at any time by changing P-16 back to "nor"
manually. (NOTE: This feature was modified to include the automatic, early cancellation in software revision A15.)
P-17: Water Temperature Differential
This parameter sets the temperature differential between ambient air temperature and hydronic water temperature that controls
the water valve. For example, selecting 10°F opens the valve when water temperature is ten degrees less than ambient in
cooling mode and 10°F greater than ambient in the heating mode.
Careful selection of the temperature differential can fully utilize the ship's heating and cooling resources. For example, while in
cooling mode and using a ten degree value, the valve will open to allow some cooling while the hydronic system is coming down
to temperature. See Figure 2 on page 11 for a graphical explanation of this parameter.
P-18: Air Filter Cleaning/Replacement Timer Setting
(Available only in software revision A15 and newer.) Use this feature for a reminder to clean or replace the unit's air filter.
The parameter entered represents that number times 10 hours. Select the number of operating hours until the filter reminder
appears. Parameter choices are between 10 (100 hours) and 250 (2500 hours). Dometic recommends that you check the air
filter at least every 500 hours of operation. The default setting is off, designated with "00".
Once set, the timer keeps track of the total amount of run hours that the fan accumulates (see P-19). Once the timer setting is
reached, "FIL" flashes briefly on the LED display every 10 seconds until it is cleared. Display of the room temperature continues
and the normal operation of the system is not affected. The "FIL" reminder can only be cleared and the timer reset via
programmable parameter P-19. See below for instructions.
8
AH-Elite Control Operations Manual
L-2229 ENGLISH
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