Piping Connections - Carrier 30HXC Series Installation, Operation And Maintenance Instructions

11.8 - Piping connections

Refer to the certified dimensional drawings for the sizes and
positions of all water inlet and outlet connections. The water
pipes must not transmit any radial or axial force to the heat
exchangers or any vibration to the pipework or building.
The water supply must be analysed and appropriate filtering,
treatment, control devices, isolation and bleed valves and
circuits built in, as necessary. Consult either a water treatment
specialist or appropriate literature on the subject.
11.8.1 - Operating precautions
The water circuit should be designed to have the least number
of elbows and horizontal pipe runs at different levels. The
following basic checks should be done (see also the illustration
of a typical hydraulic circuit below).
• Note the water inlets and outlets of the heat exchangers.
• Install manual or automatic air purge valves at all high points
in the water circuit.
• Use an expansion chamber or an expansion/relief valve to
maintain pressure in the system.
• Install water thermometers and pressure gauges in both the
entering and leaving water connections close to the
evaporator.
• Install drain valves at all low points to allow the whole
circuit to be drained. Connect a stop valve in the drain line
before operating the chiller.
• Install stop valves and pressure gauges, close to the
evaporator, in the entering and leaving water lines.
• Install cooler flow switch.
• Use flexible connections to reduce the transmission of
vibration to the pipework.
• Insulate all pipework, after testing for leaks, both to reduce
thermal leaks and to prevent condensation.
• Cover the insulation with a vapour barrier.
11.8.2 - Evaporator and condenser connections
The evaporator and condenser are of the multi-tube shell and
tube type with removable water boxes to facilitate cleaning of
the tubes.
Before making water connections tighten the bolts in both
heads to the lower torque shown, following the method
described. Tighten in the pairs and sequence indicated
according to the size of bolt (see table) using a torque value at
the low end of the range given.
CAUTION
Remove the factory supplied flat flange from the water box
before welding piping to the flange. Failure to remove the
flange may damage the sensors and insulation.
NOTE
We recommend draining the system and disconnecting the
pipework to ensure that the bolts of the heads to which the
pipework is connected are correctly and uniformly tightened.
22
11.8.3 - Freeze protection
Evaporator and water-cooled condenser protection
If the chiller or the water piping is in an area where the
ambient temperature can fall below 0°C it is recommended to
add an antifreeze solution to protect the unit and the water
piping to a temperature of 8 K below the lowest temperature.
Use only antifreeze solutions, approved for heat exchanger
duty. If the system is not protected by an antifreeze solution
and will not be used during the freezing weather conditions,
draining of the cooler and outdoor piping is mandatory.
Damage due to freezing is not covered by the warranty.
Water box tightening sequence
Legend
1 Sequence 1: 1 2 3 4
Sequence 2: 5 6 7 8
Sequence 3: 9 10 11 12
2 Tightening torque
Bolt size M16 - 171 - 210 Nm
Typical hydraulic circuit diagram
2
1
9
12
10
11
Legend
1 Control valve
2 Air vent
3 Flow switch
4 Flexible connection
5 Heat exchanger
6 Pressure tap
7 Thermostat sleeve
8 Drain
9 Buffer tank
10 Filter
11 Expansion tank
12 Fill valve
3
5
4
6
8
7