Yazaki CH-K30, Operating Instruction

Page: 7 / 16

7
OPERATION
COOLING
To engage the unit in Cool mode, press
the COOL button on the Control Panel.
Then choose between RUN and REMOTE
setting. If the unit was not in Heat mode
prior to this point, and the unit is Enabled,
then the unit will engage in cool mode
immediately. If, however, the unit was
previously in Heat mode, the unit will engage
a 30-minute mode change timer and the
PRETIME light will illuminate. Once the 30-
minute timer has expired, the PRETIME light
will go out and the unit will engage Cool
mode immediately.
HEATING
To engage a chiller-heater in Heat mode,
press the HEAT button on the Control Panel.
Then choose between RUN and REMOTE
setting. If the unit was not in Cool mode
prior to this point, and the unit is Enabled,
the unit will engage in heat mode
immediately. If, however, the unit was
previously in Cool mode, the unit will engage
a 30-minute mode change timer and the
PRETIME light will illuminate. Once the 30-
minute timer has expired, the PRETIME light
will go out and the unit will engage Heat
mode immediately.
SAFETY CONTROLS
Safety and limit controls monitor critical
operating conditions within the chiller-heater
and will shut down the unit when abnormal
conditions arise. An Error Code that
designates the cause of the shutdown
(see
Table 2)
is displayed on the control panel.
When the abnormal condition has been
cleared, press the alarm RESET button to
restart the cooling or heating operation. If
Error Code 52 is amongst the codes being
displayed, it will also be necessary to press
the RESET button on the burner controller
itself. If the unit does not restart, then
contact your ASP.
REMOTE CONTROL
The chiller-heater can be Enabled or
Disabled remotely. It can also be instructed
to change between Cool and Heat modes
remotely. No other remote control capability
exists. To enable the unit to be controlled
remotely, switch the unit into REMOTE. The
unit will now Enable or Disable based on the
external connection signals tied into the
Junction Box.
If the unit is in RUN, the unit will ignore
Enable/Disable signals from the remote
signal source, but the unit will still follow
remote Cool/Heat changeover commands
while set to RUN.
PRECAUTIONS
1. Ensure that all AUTO-OFF-HAND
switches for external pumps and the
cooling tower fan are set in the AUTO
position during normal operation. The
chiller-heater is designed to automatically
control the chilled water pump, cooling
water pump, and cooling tower fan.
2. At the beginning of the cooling season
clean and refill the cooling tower with
fresh water.
3. During the winter season the cooling
tower and cooling water circuits should be
drained to avoid freezing and scaling in
the absorber and condenser circuits.
4. When two or more absorption chiller-
heater modules are installed in parallel,
set all units for the same operating mode.
Leaving water temperature set points may
differ, but operating mode must always be
the same.