Dometic PGD1 User Manual

20
EN
Operation VARC Chiller Controls
• If setpoint is reached, the compressor reduces its
speed to maintain the water temperature. Once it has
reached temperature and a hysteresis of one degree,
the compressor turns off and the reversing valve turns
off immediately.
• A stage has a minimum run time of 60 seconds before
it can be turned off and a minimum off time of 10
seconds before it can be re-enabled. If the system calls
for a stage to be toggled on or off, the next available
stage that meets the staging criteria is used.
Compressor rotation is active during run mode:
• The compressor with the lowest running hours
is enabled first and compressor with the highest
running hours is disabled first.
• Enable Reverse Cycle Heat only for the system.
• Aer chilled water and sea water flows are stable for
10 seconds (default), the first stage is enabled and the
compressor starts.
• The first stage continues to run up to 100 percent
speed before enabling the next stage.
• If the PID loop requires demand, the next stage is
enabled with a startup delay of three minutes before
running up to the required speed.
Electric Heat (Optional Heater Barrel)
When Electric Heat is selected on the touch screen or
LCD buttons, the VARC starts heating according to the
temperature setpoint.
The VARC energizes the heater relay if return/supply
water temperature is below the programmed setpoint
and the staging delay has elapsed in a multi-stage
configuration.
Heater rotation is active during run mode:
• The heater with the lowest running hours is enabled
first and the heater with the highest running hours is
disabled first.
• Enable Electric Heat only for the system.
• Aer chilled water flow is stable for 10 seconds, the
first stage is enabled and the electric heater starts.
• The first stage continues to run for five minutes before
enabling the next stage.
• If the PID loop requires demand, the next stage is
enabled.
6.1.2 Pump Operation
The pump modes adjust as required by the system
operating mode.
Chilled Water Pump
The chilled water pump relay closes if the system is in
Heat or Cool mode. The pump is enabled five seconds
prior to the first stage being enabled. The pump is on for
continuous operation when system is enabled.
Sea Water Pump
The sea water pump has selectable operating modes
between continuous operation or cycle-with-compressor
operation. The default configuration is to cycle with the
demand.
The sea water pump relay closes five seconds before the
compressor starts in Heat or Cool modes. It opens five
seconds aer the last compressor cycle is completed. If
immersion heating is available and used, the sea water
pump is disabled.
6.1.3 Current Power Limiting
The Econo Mode provides control over the capacity of
the system. When the user enables econo mode, the
system is limited by the speed of the compressor.
The default value for econo mode is 65%. Under
setpoints, the user can adjust the Econo Mode value
between 35% and 90%.

Dometic PGD1 Specifications

General

Brand	Dometic
Model	PGD1
Category	Control Unit
Language	English