Technical data
15
Power supply
The power supply must conform to the specification on the
chiller nameplate. The supply voltage must be within the range
specified in the electrical data table.
For connections refer to the wiring diagrams.
WARNING: Operation of the chiller with an improper supply
voltage or with excessive phase imbalance constitutes abuse
which will invalidate the Carrier warranty. If the phase
imbalance exceeds 2% for voltage, contact your local
electricity supply company at once and ensure that the chiller
is not switched on until corrective measures have been taken.
Voltage phase imbalance (%) :
= 100 x max.deviation from average voltage deviation
Average voltage
Electrical checks
WARNING: Never switch off the power supply to the crankcase
heaters unless the chiller is out of service for a seasonal
shutdown or lengthy repair. The heaters must be re-energised
for at least 24 hours before the chiller is restarted.
1. Switch the unit off.
2. Open the control circuit disconnect switch.
3. Check the transformer connections.
4. Ensure that the control circuit corresponds to the wiring
diagram for the unit.
5. Check that all electrical connections are secure at the
terminals, contactors, bus bars and compressor terminal
blocks.
Start-up
Preliminary checks
• Never be tempted to start the chiller without reading fully,
and understanding, the operating instructions and without
having carried out the following pre-start checks :
• Confirm that all crankcase heaters are working by feeling
all compressor crankcases. Every compressor has a
cartridge heater (see the wiring diagram). The heater
remains energised even when the chiller is shut down to
stop the lubricating oil from absorbing refrigerant.
• Check the operation of all accessories - chilled water
circulating pumps, air handlers and other equipment
connected to the evaporator. Follow the individual
manufacturer's instructions for this equipment.
• It is recommended to connect the auxiliary contact of the
water pump contactor to ensure maximum unit safety (see
wiring diagram delivered with the unit).
• Fill the chilled water circuit with clean water, and an
inhibitor formulated specifically for this purpose, or fill it
with another non-corrosive fluid to be chilled.
• Purge air at all high points in the system. If water tempera-
tures below 4°C (30GH) or 5°C (30GZ) are likely, add the
appropriate volume of ethylene glycol to prevent freezing.
• Confirm that the suction and discharge line stop valves are
fully opened.
• Open the refrigerant line valves. Check again that the
water circuit valves are open.
Hydraulic diagram
IMPORTANT: The flow controller prevents any unit start-up if
the flow rate is not sufficient.
Its changeover point is controlled and calibrated at the factory.
Hydraulic connections
Please refer to the previous chapter.
Install purge valves and drain valves for the unit and the
system (a drain valve is provided in the lower part of the buffer
tank with a quarter turn globe valve).
Purge valves must be installed at all high points of the system,
with a drain valve at the lowest point.
The standard filter can be backed up by a supplementary filter
in the external circuit, if the mesh or filter is inadequate.
IMPORTANT: The defrost function, using an electric trace
heater, has continued power supply to the heater, if the pump is
switched off. This allows keeping the HYDROFLOW module
frost-free down to an outdoor air temperature of -12
°
C.
Outside drains and pipes for the HYDROFLOW module are
recommended, if the unit is not used at temperatures below
0
°
C. It is recommended to protect the chilled water pipes that
are exposed to low ambient temperatures by a strip heater and
by wrapping them with closed-cell insulation material of 19 mm
thickness.
1 Evaporator
2 Water flow switch
3 Buffer tank
4 Manual drain valve
5 Manual air vent valve
6 Expansion tank
7 Pressure gauge
8 Safety valve
9 Isolating valve
10 Filter
11 Pump
12/13 Isolating valves (pressure check upstream/downstream of the pump)
14 Pressure gauge