Pipework Arrangement; Wiring; Figure 8 - Chilled Liquid System - York YLAA Series Installation Operation & Maintenance

FORM 150.72-ICOM6
ISSUE DATE: 12/29/2017

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 8 - CHILLED LIQUID SYSTEM

Fan Discharge Ducting
The following duct work 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
three feet (1 meter) to obtain static regain from the fan.
Duct work should be suspended with flexible hang-
ers to prevent noise and vibration being transmitted to
the structure. A flexible joint is also recommended be-
tween 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 con-
denser coil module. No more than 3 feet (1 meter) of
light construction duct work should be supported by
the unit. Where cross winds may occur, any duct work
must be supported 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 duct work, 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 optional molded disconnect switch) in accordance
with N.E.C. or local code requirements. Minimum cir-
cuit ampacity 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
SECTION 4 – INSTALLATION
37
4