14
Always control the system from the control
panel, never at the main power supply (except
for emergency or for complete shutdown of
the system).
The standard compressors must be on a
minimum of 2 minutes and off for a minimum
of 5 minutes. The cycle rate must be no more
than 6 starts per hour.
The variable capacity compressors must be
on a minimum of 3 minutes and off for a
minimum of 3 minutes. The cycle rate must
be no more than 6 starts per hour.
The chiller is furnished with a pressure
differential switch that is factory installed
between the chilled water supply and return
connections. This sensor must not be
bypassed since it provides a signal to the unit
controller that water flow is present in the
heat exchanger and the unit can operate
without the danger of freezing the liquid.
The compressor life will be seriously
shortened by reduced lubrication, and the
pumping of excessive amounts of liquid oil
and refrigerant.
Wiring Diagrams
A complete set of unit specific wiring
diagram in point-to-point form is laminated
in plastic and located inside the control
compartment door.
General Maintenance
When the initial startup is made and on a
periodic schedule during operation, it is
necessary to perform routine service checks
on the performance of the chiller. This
includes reading and recording suction
pressures and checking for normal sub-
cooling and superheat.
Primary Pumping Package
Primary pumping uses a single pump to move
water (or glycol) through the evaporator and
back to the building. This pumping package
provides the necessary flow of water to the
system. The pump is activated whenever the
chiller is given a run signal.
Water enters the unit through the return water
piping, and then the water flows through a
suction guide with strainer. Some units will
not include a suction guide if there is enough
straight piping before the pump. The end of
the suction guide is removable for strainer
access. The strainer assembly is composed of
two parts, the operational strainer, and the
startup
strainer,
(located
inside
the
operational strainer) which is to be removed
24 hours after startup. The strainer will be
included on all units.
FIELD WIRED CONNECTIONS
Some units may require field wired
connections. Refer to the wiring
diagrams contained within the unit to
identify any components or controls
requiring additional wiring in the field
before placing the unit into service. All
additional field wiring should be
performed by a Factory Trained
Service Technician.
CAUTION
Summary of Contents for LF Series
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