Jetson FWCD Series, Installation Operation & Maintenance, Page: 53 / 96

Jetson
www.JetsonHVAC.com
53
•
A volume buffer tank located in the return water
piping.
Larger system supply and return header piping
(which also reduces system pressure drop and
pump energy use).
Minimum Water Volume for a Process
Application
If a chiller is attached to an on/off load such as a
process load, it may be difficult for the controller
to respond quickly enough to the very rapid change
in return solution temperature if the system has
only the minimum water volume recommended.
Such systems may cause chiller low temperature
safety trips or in the extreme case evaporator
freezing. In this case, it may be necessary to add or
increase the size of the mixing tank in the return
line.
Unit Piping
See “Piping System Flushing Procedure,” for
information on piping system flushing procedure,
and water treatment requirements.
Exchanger Water Pressures
CAUTION
Vessel Damage!
To prevent pressure vessel damage, do not
exceed
unit nameplate water-side
pressures.
If field installed gauges are used, provide shutoff
valves in the line(s) to the gauge(s) to isolate the
gauges when not in use.
Flow Sensing Devices
CAUTION
Unexpected Chiller Start!
Failure to follow instructions could cause
the chiller to start unexpectedly which
could result in equipment or property
damage. An external source (EMS, time
clock or any other means) should not be
allowed to bring on a pump that would
trigger the flow switch to start the chiller.
The flow switch is meant to act as a safety
switch and not a start/stop mechanism.
Chilled water flow switch, or other factory
approved flow proving device is mandatory; field
installation by contractor is required. Flow switch
is
to be installed and maintained per
manufacturer’s recommendations and
interconnected to the control panel as described on
the wiring diagram. To provide additional chiller
protection, install and wire the flow switch in
series with chilled water pump interlock for the
chilled water circuits. Specific connection and
schematic wiring diagrams ship with the unit
inside the control box.
Water Piping Recommendations
All water piping must be cleaned and flushed
according to Piping System Flushing Procedure
later in this manual prior to circulating any water
through unit.
Make sure water piping connections to the
evaporator and condenser are isolated, and confirm
that all piping to unit is supported independently to
prevent any load being transferred to the unit. Use
unions, flanges or grooved lock type fittings to
facilitate service procedures. Use a pipe sealant
such as Teflon
®
tape on all threaded water
connections. Use vibration eliminators to prevent
transmitting vibrations through the water lines.