IOM 1210-7 • MAGNITUDE
®
MODEL WMC CHILLERS
16 www.DaikinApplied.com
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Water Piping
Be sure that water inlet and outlet connections match certified
drawings and nozzle markings. All evaporators and condensers
have OGS-type grooved water connections (adhering to
Standard AWWA C606) or optional flange connections. The
installing contractor must provide matching mechanical
connections. PVC piping should not be used.
CAUTION
If welding is to be performed on the mechanical or flange
connections:
1. Remove the solid-state temperature sensor, thermostat
bulbs, and nozzle mounted flow switches from the wells
to prevent damage to those components.
2. Properly ground the unit or severe damage to the
MicroTech
®
II unit controller can occur.
NOTE:
ASME certification will be revoked if welding is
performed on a vessel shell or tube sheet.
The water heads can be interchanged (end for end) so that
the water connections can be made at either end of the unit.
If this is done, use new head gaskets and relocate the control
sensors.
Field installed water piping to the chiller must include:
• air vents at the high points.
• a cleanable water strainer upstream of the evaporator
and condenser inlet connections.
• a flow proving device for both the evaporator and
condenser to prevent freeze up. Flow switches, thermal
dispersion switches, or Delta-P switches can be used.
Note that thermal dispersion flow switches are factory
installed as standard. Additional flow switches can be
used only if they are connected in series with the ones
already provided. Connect additional flow switches in
series between CF1 and CF2, shown in
starting on
• sufficient shutoff valves to allow vessel isolation. The
chiller must be capable of draining the water from the
evaporator or condenser without draining the complete system.
It is recommended that field installed water piping to the chiller
include:
• thermometers at the inlet and outlet connections of both
vessels.
• water pressure gauge connection taps and gauges at the
inlet and outlet connections of both vessels for measuring
water pressure drop.
CAUTION
When common piping is used for both building heating and
cooling modes, care must be taken to provide that water
flowing through the evaporator cannot exceed 110°F. Water
this hot can damage controls or cause the relief valve to
discharge refrigerant.
Piping must be supported to eliminate weight and strain on
the fittings and connections. Chilled water piping must be
adequately insulated.
Checking Piping Circuits and Venting Air
After the water piping is completed tighten and torque to
maintain between 30 and 60 ft. lbs. (41 and 81 N•m) the
nuts on the liquid head flanges on both the evaporator and
condenser. It is recommended that the evaporator head
not be insulated until this is completed. Gasket shrinkage
and handling during transit cause nuts to loosen. If water
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.
Vessel Drains at Startup
The unit is drained of water at the factory. Drain plugs for each
vessel head are shipped separately in the contorl box. Units
are shipped with the drain plug in the top water box drain
hole and no plug in the bottom drain hole. Be sure to install
the bottom drain plugs prior to filling the vessel with fluid. See
Figure 15: Drain Plug Installation