SECTION 4 - INSTALLATION
JOHNSON CONTROLS
37
Form 201.28-NM1.1
Issue date: 08/06/2021
4
Vibration isolators
Optional sets of vibration isolators can be supplied
loose with each unit.
Use the isolator tables shipped with the unit in the in-
formation pack. Identify each mount and its correct lo-
cation on the unit.
Installation
Place each mount in its correct position and lower the
unit carefully onto the mounts ensuring the mount
engages in the mounting holes in the unit base frame.
On adjustable mounts, transfer the unit weight even-
ly to the springs by turning the mount adjusting nuts
(located just below the top plate of the mount) counter-
clockwise to raise and clockwise to lower. This should
be done two turns at a time until the top plates of all
mounts are between 1/4 in. (6 mm) and 1/2 in. (12 mm)
clear of top of their housing and the unit base is level.
Shipping braces
The chiller’s modular design does not require shipping
braces.
Chilled liquid piping
General requirements
The following piping recommendations are intended
to ensure satisfactory operation of the units. Failure to
follow these recommendations could cause damage to
the unit, or loss of performance, and may invalidate the
warranty.
The maximum flow rate and pressure drop
for the evaporator must not be exceeded at
any time. See
, for details.
The Maximum acceptable Chilled Liquid
pressure in the inlet of Evaporator is same
as the statement in "Maximum Tube Side
Pressure" of Pressure Vessel Name Plate
for YVAA and YVFA with Falling Film
Evaporator.
The liquid must enter the evaporator at
the inlet connection. The standard inlet
connection for the evaporator is opposite
the control panel end of the evaporator.
A flow switch must be installed in the
customer piping at the outlet of the
evaporator and wired back to the control
panel using shielded cable.
There should be a straight run of piping of at least
5 pipe diameters on either side. The flow switch should
be wired to Terminals 2 and 13 on the 1TB terminal
block. A flow switch is required to prevent damage to
the evaporator caused by the unit operating without
adequate liquid flow.
The flow switch used must have gold plated contacts for
low voltage/current operation. Paddle type flow switch-
es suitable for 10 bar (150 psig) working pressure and
having a 1 in. N.P.T. connection can be obtained from
Johnson Controls as an accessory for the unit. Alterna-
tively, a differential pressure switch fitted across an ori-
fice plate may be used, preferably of the high/low limit
type.
Another alternative flow switch is a thermal dispersion
flow switch.
The chilled liquid pumps installed in the piping sys-
tems should discharge directly into the unit evaporator
section of the system. The pumps may be controlled by
the chiller controls or external to the unit.
Pipework and fittings must be separately supported to
prevent any loading on the evaporator. Flexible con-
nections are recommended which will also minimize
transmission of vibrations to the building. Flexible
connections must be used if the unit is mounted on
anti-vibration mounts, as some movement of the unit
can be expected in normal operation.
Piping and fittings immediately next to the evapora-
tor should be readily de-mountable to enable cleaning
before operation, and to facilitate visual inspection of
the exchanger nozzles.
The evaporator must be protected by a
strainer, preferably of 16 mesh, fitted as
close as possible to the liquid inlet connec-
tion, and provided with a means of local
isolation.
The evaporator must not be exposed to flushing veloci-
ties or debris released during flushing. It is recommend-
ed that a suitably sized bypass and valve arrangement
is installed to allow flushing of the piping system. The
bypass can be used during maintenance to isolate the
heat exchanger without disrupting flow to other units.
When flushing the system, do not allow system water to
flow through the chiller heat exchangers.
Thermometer and pressure gauge connections should
be provided on the inlet and outlet connections of each
evaporator. Gauges and thermometers are not provided
with the unit and are to be furnished by others.
