JOHNSON CONTROLS
20
FORM 160.69-N2
ISSUE DATE: 7/31/2015
SECTION 2 - INSTALLATION
piping, a connection in each line as close to the unit
as possible should be opened, by removing the flange
bolts or coupling and checked for piping alignment. If
any of the bolts are bound in their holes, or if the con-
nection springs are out of alignment, the misalignment
must be corrected by properly supporting the piping or
by applying heat to anneal the pipe.
If the piping is annealed to relieve stress
the inside of the pipe must be cleaned of
scale before it is nally bolted in place.
EVAPORATOR AND CONDENSER WATER
PIPING
The evaporator and condenser liquid heads of chiller
have nozzles which are grooved, suitable for welding
150 psig DWP flanges or the use of Victaulic cou-
plings. Factory mounted flanges are optional.
The nozzles and water pass arrangements are furnished
in accordance with the job requirements (see Product
Drawings) furnished with the job. Standard units are
designed for 150 psig DWP on the water side. If job
requirements are for greater than 150 psig DWP, check
the unit data plate before applying pressure to evapora-
tor or condenser to determine if the chiller has provi-
sions for the required DWP.
Inlet and outlet connections are identified by labels
placed adjacent to each nozzle.
Chilled Water
Foreign objects which could lodge in, or block flow
through, the evaporator and condenser tubes must be
kept out of the water circuit. All water piping must be
cleaned or flushed before being connected to the chiller
pumps, or other equipment.
Permanent strainers (supplied by others) are required
in both the evaporator and condenser water circuits to
protect the chiller as well as the pumps, tower spray
nozzles, chilled water coils and controls, etc. The
strainer must be installed in the entering chilled water
line, directly upstream of the chiller.
Water piping circuits should be arranged so that the
pumps discharge through the chiller, and should be
controlled as necessary to maintain essentially constant
chilled and condenser water flows through the unit at
all load conditions.
If pumps discharge through the chiller, the strainer
may be located upstream from pumps to protect both
pump and chiller. (Piping between strainer, pump and
chiller must be very carefully cleaned before start-up.)
If pumps are remotely installed from chiller, strainers
should be located directly upstream of the chiller.
Condenser Water Circuit
For proper operation of the unit, condenser refrigerant
pressure must be maintained above evaporator pressure.
If operating conditions will fulfill this requirement, no
attempt should be made to control condenser water
temperature by means of automatic valves, cycling of
the cooling tower fan or other means, since chillers are
designed to function satisfactorily and efficiently when
condenser water is allowed to seek its own temperature
level at reduced loads and off-peak seasons of the year.
However, if entering condenser water temperature can
go below the required minimum, (refer to 160.69-O2)
condenser water temperature must be maintained equal
to or slightly higher than the required minimum. Re-
fer to Figure 7 on page 21 for typical water piping
schematic.
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