Installation of vibration isolators
An optional set of vibration isolators can be supplied loose with each unit. The correct number of
isolators are supplied to suit the unit model with or without a hydro kit.
Pipework arrangement
The following piping recommendations are intended to ensure satisfactory operation of the unit.
Failure to follow these recommendations could cause damage to the unit, or loss of performance,
and may invalidate the warranty. See Figure 38 and Figure 39 for pipwork arrangement.
For two-pipe units, a flow switch is included as standard on each module. It is factory-wired and
installed in the extension pipe between heat exchanger outlet and edge of chiller. For four-pipe
units, a flow switch is packaged as accessory and is installed on the heat exchanger outlet pipe at
side.
Support pipework and fittings separately, to prevent any loading on the heat exchangers. Flexible
connections are recommended, which also minimizes transmission of vibrations to the building.
Use flexible connections if the unit is mounted on anti-vibration mounts because some movement
of the unit can be expected in normal operation.
Pipework and fittings immediately next to the heat exchangers must be readily demountable to
enable cleaning before operation, and to facilitate visual inspection of the exchanger nozzles.
Protect each heat exchanger by a strainer, preferably at least 30 mesh, fitted as close as possible to
the liquid inlet connection pf the PHE, and provided with a means of local isolation. A 30-mesh wye-
strainer is provided as standard to provide protection at the heat exchanger inlet.
The heat exchangers must not be exposed to flushing velocities or debris released during flushing.
It is recommended that a suitably sized by-pass and valve arrangement be installed to allow
flushing of the pipework system. The by-pass can be used during maintenance to isolate the heat
exchangers without disrupting flow to other units.
Johnson Controls suggests providing thermometer and pressure gauge connections on the inlet
and outlet connections of each heat exchanger.
Provide drain and air vent connections at all low and high points in the pipework to permit drainage
of the system, and to vent any air in the pipes.
Protect liquid systems at risk of freezing, due to low ambient temperatures, by using insulation and
heater tape or a suitable glycol solution. The liquid pumps must also be used to ensure liquid is
circulated when the ambient temperature approaches freezing point. Install insulation around the
heat exchanger nozzles also.
Heater tape of appropriate heating capacity based on the location’s conditions is required. This
is supplied independently and controlled by an ambient temperature thermostat set to switch
on when the ambient temperature is below 26.6ºF (-3ºC). Water piping systems require site
installations to ensure that water temperature is 5.4ºF to 9ºF (3ºC to 5ºC) above freezing point at all
times.
The heat exchanger is protected by a heater placed under the insulation, which is powered from
the unit control system power supply. During cold weather when there is a risk of freezing, leave
the unit switched on to provide the freeze protection function, unless the liquid systems have been
drained.
Connection types and sizes
Standard pipework connections are Victaulic-groove type. For connection sizes for each models see
Table 10 and Table 11.
YMAE Air-Cooled Inverter Scroll Chiller and Heat Pump54
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