15 Electrical installation
Installation and operation manual
31
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
15.8
To connect the optional wiring
For the optional wiring use insulated wires of a rated voltage of
250 V or higher and a minimal cross section of 1.25 mm² for single
core wires and 0.75 mm² for multicore wires.
Variable water flow
The variable water flow output signal is a low voltage control signal
which generates an output of 2~10 V DC depending on the required
water flow rate through the plate heat exchanger. For more
information, see
"14.2.3 About the water flow rate"
20].
NOTICE
The maximum output power of the 2~10 V DC output
signal is 50 mW. Exceeding this power can result in
damage of the system.
Always use shielded cables with a minimal cross section of
0.75 mm² and a length limited to 100 m.
The control line of the valve/pump should be connected to the X2M
connector in the electrical switchbox. To connect the valve/pump to
the outdoor unit, also provide a separate 12 V DC power supply
(with an output power of at least 50 mW) to the X2M connector.
Connect the valve/pump to: X2M terminals 2 and 3.
Connect the power source to X2M terminals 1 and 3 (respect the
polarity).
BLK
INTER
LOCK
TW1
IN
TW2
OUT
WHT
BLU
BLU
BLU
YLW
ORG
RED
BRN
+ –
1 2 3 4 5 6 7 8 9 10
X2M
+
–
2~10 V DC
12 V DC
a
b
X2M
a
Valve/pump
b
Power supply
NOTICE
Make sure to connect a flow switch to your water-cooled
VRV IV system. Running the system with a flow rate below
the minimum requirement can result in damage of the
system.
Interlock
It is mandatory to connect a flow switch to the interlock circuit of the
outdoor unit. Running the system with a flow rate below the
minimum requirement can result in damage of the system. The flow
switch should be installed in the main water circuit between the plate
heat exchanger and the closed valve. Select a flow switch contact of
at least 15 V DC, 1 mA.
Connect the flow switch to: X2M terminals 5 and 6.
In case of a multi outdoor unit system, install one or more flow
switches depending on the installation of the water system so that
water flow is guaranteed under every condition.
NOTICE
If the flow switch is installed in a variable water flow
system, take into account the inertia of the water flow. If a
variable water flow system is used, the flow switch control
should be linked to the compressor operation using the
multifunction output terminal "b".
Failure to do so will result in unintended "forced thermo off"
conditions.
Example:
X3M
X3M
YLW
a
b
c
d
e
ORG
RED
BRN
BLU
BLU
WHT
WHT
BLK
BLK
BLK
TW1
IN
TW2
OUT
WHT
BLU
BLU
BLU
YLW
ORG
RED
BRN
0
10
+ -
1 2 3 4 5 6 7 8 9 10
X2M
b
a
X2M
a
Relay (normally closed) (field supply)
b
Flow switch (field supply)
Multifunction outputs
To monitor the outdoor unit operation or trigger field supplied
equipment connected to the outdoor unit, this RWEYQ*T9, series is
equipped with 5 output contacts.
General contact specifications: 220 V AC, 3 mA-0.5 A.
To connect these output signals, choose the applicable contacts in
the X3M terminal in the table below:
X3M
X3M
YLW
a
b
c
d
e
ORG
RED
BRN
BLU
BLU
WHT
WHT
BLK
BLK
Terminal
Function
a
Error on remote controller
b
Compressor operation
c
Heating operation
d
Cooling operation
e
Water pump operation request
15.9
To check the insulation resistance
of the compressor
NOTICE
If, after installation, refrigerant accumulates in the
compressor, the insulation resistance over the poles can
drop, but if it is at least 1 MΩ, then the unit will not break
down.
▪ Use a 500 V mega-tester when measuring insulation.
▪ Do NOT use a mega-tester for low voltage circuits.
1
Measure the insulation resistance over the poles.
If
Then
≥1 MΩ
Insulation resistance is OK. This procedure
is finished.
<1 MΩ
Insulation resistance is not OK. Go to the
next step.
2
Turn ON the power and leave it on for 6 hours.
Result:
The compressor will heat up and evaporate any
refrigerant in the compressor.
