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Form 150.72-ICOM6
Issue date: 12/19/2023
Pipework arrangement
The following are suggested pipework arrangements
for single unit installations, for multiple unit installa-
tions, each unit should be piped as shown.
Recommendations of the Building Services Re-
search Association.
B
P
H
X
ISOLATING VALVE - NORMALLY OPEN
ISOLATING VALVE - NORMALLY CLOSED
FLOW REGULATING VALVE
FLOW MEASUREMENT DEVICE
STRAINER
PRESSURE TAPPING
FLOW SWITCH
FLANGED CONNECTION
Figure 9: Chilled liquid system
Fan discharge ducting
The following ductwork recommendations are intend-
ed 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.
Johnson Controls
When ducting is to be fitted to the fan discharge it is
recommended that the duct should be the same cross-
sectional area as the fan outlet and straight for at least
3 ft (1 m) to obtain static regain from the fan. Ductwork
should be suspended with flexible hangers to prevent
noise and vibration being transmitted to the structure.
A flexible joint is also recommended between the duct
attached to the fan and the next section for the same
reason. Flexible connectors should not be allowed to
concertina.
The unit is not designed to take structural loading. No
significant amount of weight should be allowed to rest
on the fan outlet flange, deck assemblies, or condenser
coil module. No more than 3 ft (1 m) of light construc-
tion ductwork should be supported by the unit. Where
cross winds may occur, any ductwork must be support-
ed to prevent side loading on the unit.
LD06596a
If the ducts from two or more fans are to be combined
into a common duct, back-flow dampers should be fit-
ted in the individual fan ducts. This will prevent re-
circulation of air when only one of the fans is running.
Units are supplied with outlet guards for safety and to
prevent damage to the fan blades. If these guards are
removed to fit ductwork, adequate alternative precau-
tions must be taken to ensure persons cannot be harmed
or put at risk from rotating fan blades.
Wiring
Liquid chillers are shipped with all factory-mounted
controls wired for operation.
Field wiring: Power wiring must be provided through
a fused disconnect switch to the unit terminals (or op-
tional molded disconnect switch) in accordance with
NEC or local code requirements. Minimum circuit am-
pacity and maximum dual element fuse size are given
in the Electrical Data tables.
Copper power wiring only should be used for supply-
ing power to the chiller. This is recommended to avoid
LD06597A
safety and reliability issues resulting from connection
failure at the power connections to the chiller. Alumi-
num wiring is not recommended due to thermal char-
acteristics that may cause loose terminations result-
ing from the contraction and expansion of the wiring.
Aluminum oxide may also build up at the termination
causing hot spots and eventual failure. If aluminum
wiring is used to supply power to the chiller, AL-CU
compression fittings should be used to transition from
aluminum to copper. This transition should be done in
Section 4: Installation
4
39
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