Johnson Controls YORK YK Style G OPTIVIEW, Эксплуатация и обслуживание, Страница: 277 / 306

JOHNSON CONTROLS
17
SECTION 2 - INSTALLATION
FORM 160.75-N1
ISSUE DATE: 4/30/2014
2
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 Operation -
Unit (Form 160.75-O1) condenser water temperature
must be maintained equal to or slightly higher than the
required minimum. Refer to
Figure 7 on Page 16
for
typical water piping schematic.
Stop Valves
Stop valves may be provided (by others) in the evapora-
tor and condenser water piping adjacent to the unit to
facilitate maintenance. Thermometer wells and pressure
taps should be provided (by others) in the piping as close
to the unit as possible to facilitate operating check.
Flow Switches
Thermal type water flow switches are factory mount-
ed in the chilled and condensed water nozzles and are
factory wired to the OptiView™ control panel. These
solid-state flow sensors have a small internal heat-
ing element and use the cooling effect of the flowing
fluid to sense when an adequate flow rate has been
established.
Waterbox Drain and Vent Valves
Drain and vent valves (by others) should be installed
in the connections provided in the evaporator and con-
denser liquid heads. These connections may be piped
to drain if desired.
Checking Piping Circuits and Venting Air
After the water piping is completed, but before any
waterbox insulation is applied. Tighten and torque to
maintain between 30 and 60 ft. lbs. (41 and 81 N·m)
the nuts on the liquid head flanges. Gasket shrinkage
and handling during transit cause nuts to loosen. If wa-
ter pressure is applied before tightening is done, the
gaskets may be damaged and have to be replaced. Fill
the chilled and condenser water circuits, operate the
pumps manually and carefully check the evaporator
and condenser water heads and piping for leaks. Repair
leaks as necessary.
Before initial operation of the unit both water circuits
should be thoroughly vented of all air at the high points.
FIGURE 8 -
TYPICAL REFRIGERANT VENT PIPING
FLANGED JOINT
TO PERMIT PIPING
DISASSEMBLY
CONDENSATION
TRAP
DUAL RELIEF
VALVES
VENT TO ATMOSPHERE
SUPPORT VENT PIPING TO AVOID
STRAIN ON RELIEF PIPING
FLEXIBLE CONNECTOR
CONDENSER
COOLER
SEE NOTE
NOTE: SHELLS MAY BE FURNISHED WITH
ONE OR TWO RELIEF VALVES,
DEPENDING ON SHELL SIZE.
LD03863
EVAPORATOR
Condenser Water Circuit