Johnson Controls York MaxE YK Series, Руководство пользователя

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FORM 160.75-O1 (309)
19
JOHNSON CONTROLS
3
While the chiller is shut down, the orifice will be in the
fully open position causing the sensed level to be ap-
proximately 0%. When the chiller is started, after the
vane motor end switch (VMS) opens when entering
SYSTEM RUN , if actual level is less than the level
setpoint, a linearly increasing ramp is applied to the
level setpoint. This ramp causes the setpoint to go from
the initial refrigerant level (approximately 0%) to the
programmed setpoint over a programmable period of
time.
If the actual level is greater than the setpoint when the
VMS opens, there is no pulldown period, it immediately
begins to control to the programmed setpoint.
While the chiller is running, the refrigerant level is nor-
mally controlled to the level setpoint. However, anytime
the vanes fully close (VMS closes), normal level control
is terminated, any refrigerant level setpoint in effect is
cancelled and the outputs to the level control will be
constant open.
optional serVice isolation ValVes
If your chiller is equipped with optional service isola-
tion valves on the discharge and liquid line, these valves
must remain open during operation. These valves are
used for isolating the refrigerant charge in either the
evaporator or condenser to allow service access to the
system. A refrigerant pump-out unit will be required to
isolate the refrigerant.
Isolation of the refrigerant in this sys-
tem must be performed by a qualified
service technician.
optional hot gas BYpass
Hot gas bypass is optional and is used to eliminate com-
pressor surge during light load or high head operation.
The OptiView control panel will automatically modulate
the hot gas valve open and closed as required. Adjust -
ment of the hot gas control valve must be performed
by a qualified service technician following the Hot Gas
Set-up procedure.
Changes in chilled water flow will
require re-adjustment of the hot gas
control to insure proper operation.
otiVieW control center
(see section 2)
The OptiView Control Center is factory-mounted, wired
and tested. The electronic panel automatically controls
the operation of the unit in meeting system cooling re-
quirements while minimizing energy usage. For detailed
information on the Control Center, refer to “Section 2”
of this manual.
solid state starter (optional)
The Solid State Starter is a reduced voltage starter that
controls and maintains a constant current flow to the
motor during start-up. It is mounted on the chiller. Power
and control wiring between the starter and chiller are
factory installed. The starter enclosure is NEMA-1 with
a hinged access door with lock and key. Electrical lugs
for incoming power wiring are provided.
VariaBle speed driVe (optional)
A Variable Speed Drive can be factory packaged with
the chiller. It is designed to vary the compressor motor
speed and prerotation vane position by controlling the
frequency and voltage of the electrical power to the
motor. Operational information is contained in Form
160.00-O1. The control logic automatically adjusts mo-
tor speed and compressor prerotation vane position for
maximum part load efficiency by analyzing information
fed to it by sensors located throughout the chiller.