14 Piping installation
Installation and operation manual
20
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
a
Air purge (field supply)
b
Water outlet
c
Water inlet
d
Shut-off valve (field supply)
e
Water connection
f
Water piping (field supply)
g
Insulation (field supply)
h
Heat exchanger
i
Filter (accessory)
j
Drain valve (field supply)
k
Drain connection
l
Insulation cover
▪
Water pump.
After filling the water piping, run the water pump
(field supply) to flush the water piping. After flushing, clean the
filter.
▪
Freeze.
Protect against freezing.
▪
Water pipes.
ALWAYS comply with local and national regulations.
▪
Water piping
–
Tightening torque
. Securely tighten the water
piping with a tightening torque of ≤300 N•m. Overtightening results
in damage to the unit.
▪
Field supply components – Water.
Only use materials that are
compatible with water used in the system and with the materials
used in the outdoor unit.
▪
Field supply components – Water pressure and temperature.
Check that all components in the field piping can withstand the
water pressure and water temperature.
▪
Water pressure.
The maximum water pressure is 37 bar. Provide
adequate safeguards in the water circuit to ensure that the
maximum pressure is NOT exceeded.
▪
Drainage – Low points.
Provide drain taps at all low points of the
system in order to allow complete drainage of the water circuit.
▪
Drainage – Clogging.
Make sure that the water runs smoothly
without any clogging by dirt.
▪
Drainage
–
Lateral length
. Lateral length of drainage should be
as short as possible (≤400 mm) and installed in a downward
direction. The diameter of the drain pipe must be the same as the
diameter of the pipe on the outdoor unit.
▪
Non-brass metallic piping.
When using non-brass metallic
piping, insulate the brass and non-brass properly so that they do
NOT make contact with each other. This to prevent galvanic
corrosion.
14.2.2
Handling the brazed plate heat exchanger
INFORMATION
A brazed plate heat exchanger is used. Because of a
different structure from a conventional heat exchanger, it
MUST be handled in a different manner.
▪ Install a water filter at the water inlet in order to prevent foreign
materials such as dust, sand,… from entering the plate heat
exchanger.
▪ Scale can stick to the plate heat exchanger depending on water
quality. To remove scale, cleaning is necessary at regular
intervals using chemicals. Install a shut-off valve at the end in the
water piping. Install a piping connection port on the piping
between this shut-off valve and the outdoor unit for cleaning by
chemicals.
▪ For cleaning and water draining of the outdoor unit (long period of
non-use or during non-use in winter), install an air purge plug (for
joint use with cleaning port) (field supply) and a water draining
plug at the inlet/outlet ports of the water piping. Additionally, install
an automatic air purge valve (field supply) at the top of rising
piping or at the top of a portion where air tends to stay.
▪ Install an additional cleanable filter (field supply) in front of the
pump inlet.
▪ Carry out complete cooling/thermal insulation of the water piping
and the outdoor unit drain piping. If insulation has not been carried
out, the unit may sustain damage during severe winters due to
freezing, in addition to thermal loss.
▪ When you stop the unit during night or winter, take measures to
prevent water circuits from natural freezing in areas where the
ambient temperature drops below 0°C (by water drain off, keeping
the circulation pump running, warming up by a heater,…).
Freezing of water circuits may result in damage to the plate heat
exchanger. Therefore, take appropriate measures depending on
the circumstances.
a
b
c
d
e
f
g
h
i
a
Water inlet piping
b
Filter (accessory)
c
Air purge plug (for joint use with cleaning port) (field
supply)
d
Cleaning device
e
Filter for pump (field supply)
f
Automatic air purge valve (field supply)
g
Water outlet piping
h
Joint use with water draining plug
i
Plate heat exchanger
14.2.3
About the water flow rate
The RWEYQ*T9Y1B models are equipped with the logic to operate
with a variable water flow rate function.
a
b
c
a
Constant flow
b
Flow regulating valve (field supply)
c
Inverter pump (field supply)
A system can either be configured as a constant flow system (a), a
variable flow system with valve (b) or a variable flow system with a
pump (c).
▪ Constant flow system (a): the variable water flow rate function is
not used.
▪ A pressure independent flow regulating valve (b): the valve
controls the flow rate of a centralized inverter pump through the
unit.
▪ Inverter pump (c): the pump directly controls the water flow rate
through the unit.
To activate the variable flow system, change field setting [2-24] to
the applicable value. See
32].
NOTICE
Make sure that all field supplied equipment for variable
flow rate can be switched off together with the outdoor unit.
This is required when cleaning the plate heat exchanger.
NOTICE
Make sure that all field supplied equipment for variable
flow rate meet the minimum hydronic and electric
specifications. Failure to do so can result in inefficient
operation or even breakdown of the system.
