T9901018-1
Page 14 of 26
Controls Wiring to the Dry Cooling Unit (Left Hand Side of the Unit)
All electrical controls wiring and connections MUST be carried out by a
competent qualified electrician in accordance with the latest edition of the IEE
wiring regulations and/or local statutory regulations. (see also Wiring Diagram on
Page 13)
The following connections need to be made, except where stated as
optional.
Use 20mm
size cable glands or conduit connectors:
Terminal on Dry Cooling Unit
Terminal on SIEMENS RDG400
Manual Room Control
(use 0.5mm
2
max. cable size - small terminals)
1 G
2 G0
3 Y1
4 – for return air sensor in air intake
M (do not wire if using air sensor inside RDG400)
5 – for return air sensor in air intake
B1 (do not wire if using air sensor inside RDG400)
6 -
optional
DG (volt free input, for remote On/Off or
Run/Standby or Fire Alarm Circuit)
7 -
optional
D1 (ditto as above)
Terminal on Dry Cooling Unit
Optional Error Signal Output Connection
8 Mitsubishi
Electric
heat pump system, Error Signal
(volt free contacts, rated 1A max, Error = Closed)
9
Terminal on Dry Cooling Unit
Optional Room Over Temperature Alarm
Volt Free contacts rated at 16(4)A at 230V
(use 1.0mm
2
maximum cable size)
10
10 – 11 contacts close on rising temperature
11
12
11 – 12 contacts open on rising temperature
Terminal on Dry Cooling Unit
Terminal on 230V/1ph/50Hz
Water Pump – 2A maximum
(use 1.5mm
2
maximum cable size)
Pu L
L
Pu N
N
Pu E
E
Terminal on Dry Cooling Unit
(electrical supply and communications link
for interface pcb inside dry cooling unit)
Terminal on Mitsubishi Electric
PUHZ-HW140VHA/YHA2
(use 1.0mm
2
maximum cable size)
S1 S1
S2 S2
S3 S3
A local isolator to switch S1 and S2 On/Off is required within 1m of the dry cooling unit.
NB.
The interface PCB is already Earthed via the supply to the dry cooling unit.
WARNING:
400V may exist between terminal S1 and other Live terminals inside the
Thermoscreens dry cooling unit.
The Mitsubishi Electric PUHZ-HW140 Outdoor Unit needs to be installed in accordance
with the relevant sections of the Mitsubishi Electric instructions supplied with the unit.