T9901018-1
Page 17 of 26
A Mitsubishi Electric Interface PCB is located within the left hand end of the
Thermoscreens Dry Cooling Unit to provide communication between the Outdoor Unit
and the Dry Cooling Unit. The Interface PCB on its mounting plate is held in place by a
fixing screw located in the left-hand end panel of the dry cooling unit under the left-hand
plastic end cap. Remove the screw and carefully slide the pcb partially out.
Check that the dip switches on the Interface PCB are set as follows:
SW1-1, 1-5, 1-6 ON; SW1-2, 1-3, 1-4, 1-7, 1-8 OFF
SW2 – All OFF
SW3-1, 3-7 ON; SW3-2, 3-3, 3-4, 3-5, 3-6, 3-8 OFF
SW6 – Both OFF
Room temperature control of the dry cooling unit is done via a Siemens RDG400 Manual
Room Control that is supplied with the unit. This room control is used to select the target
temperature (set point) of the room air temperature and to then switch the Mitsubishi
Electric cooling system On and Off to achieve this temperature.
If there is site wiring between terminals 4 & 5 in the dry cooling unit and terminals M & B1
in the Siemens RDG400 manual room control the room air temperature will be measured
using the black return air temperature sensor clipped onto the coil in the air intake of the
dry cooling unit. If there is no wiring from terminals 4 & 5 the room air temperature will be
measured in the RDG400 manual room control using its integral air temperature sensor.
Remove the RDG400 manual room control from its back-plate (2 screws at LH side of
control and pull at LH) and check that the dip switches in the control are set as follows:
SW1-3 ON
SW1-1, 1-2, 1-4, 1-5 OFF
Check that the wiring between the Thermoscreens dry cooling unit and the Siemens
RDG400 Manual Room Control, the water pump and, if used, the remote On/Off, error
signal and room over temperature alarm is in accordance with the Wiring Diagram on
Page 13.
Check that the S1, S2, S3 wiring between the Thermoscreens dry cooling unit and the
Mitsubishi Electric outdoor unit is in accordance with the Wiring Diagram on Page 13.
Fixing screw
(accessed from
end of dry
cooling unit)
DIP
SW1
SW2
SW3
LED 1
DIP SW6
LED 3
