York YCIV 0590-1500 50Hz, Список проверок перед запуском, Страница: 3 / 12

FORM 201.23-CL1 (309)
JOHNSON CONTROLS
3
FIRSt tImE StaRt-UP
During the commissioning period there
should be sufficient heat load to run the
unit under stable full load operation
to enable the unit controls, and system
operation to be set up correctly, and a
commissioning log taken. Be sure that
the chiller is properly programmed and
the Equipment Start-up Checklist is
completed.
Interlocks
Verify that liquid is flowing through the cooler and
that heat load is present. Ensure that any remote run
interlocks are in the run position and that the daily
schedule requires the unit to run or is overridden.
Unit Switch
Place the “Unit Switch” on the keypad to the ON
position.
Start-up
Press the SYSTEM SWITCHES Key and place the
system switch for System 1 to the ON position. There
may be a few seconds delay before the first compressor
starts because of the anti-recycle timer). Be ready when
each compressor starts, to switch the Unit Switch OFF
immediately, if any unusual noises or other adverse
conditions develop.
When a compressor is running, the controller monitors
oil pressure, motor current, and various other system
parameters such as discharge pressure, chilled liquid
temperature, etc. Should any problems occur; the
control system will immediately take appropriate
action and display the nature of the fault.
Oil Pressure
When a compressor starts, press the relevant SYSTEM
PRESSURES key and verify that oil differential
pressure (oil pressure-suction pressure) develops
immediately. If oil pressure does not develop, the
automatic controls will shut down the compressor.
Under no circumstances should a restart attempt be
made on a compressor, which does not develop oil
pressure immediately. Switch the Unit Switch to the
OFF position.
Refrigerant Flow
When a compressor starts, a flow of liquid refrigerant
will be seen in the liquid line sight glass. After several
minutes of operation, and provided a full charge of
refrigerant is in the system, the bubbles will disappear
and be replaced by a solid column of liquid.
Loading
Once the unit has been started, all operations are fully
automatic. After an initial period at minimum capacity,
the control system will adjust the unit load depending
on the chilled liquid temperature and rate of temperature
change. If a high heat load is present, the controller
will increase the speed of the compressor(s).
Condenser and Fan Rotation
Once a compressor is running, discharge pressure rises
as refrigerant is pumped into the air-cooled condenser
coils. This pressure is controlled by stages of fans to
ensure maximum unit efficiency while maintaining
sufficient pressure for correct operation of the
condensers and the lubrication system.
As discharge pressure rises, the condenser fans operate
in stages to control the pressure. Verify that the fans
operate in the correct direction of rotation and operation
is correct for the type of unit.
Suction Superheat
Check suction superheat at steady full compressor
load only. Measure suction temperature with a
thermocouple on the copper line about 6” (150 mm)
before the compressor suction service valve. Measure
suction pressure at the suction transducer access valve
or the compressor suction service valve. Superheat
should be 10°F to 12°F (5.55 to 6.67°C) and should
be reasonably close to the panel display. Superheat
setting is programmable on the control panel, but is
not mechanically adjustable. The Flash Tank Drain
Valve controller modulates the 2-phase drain valve
stepper motor to control system superheat. Superheat
control is a function of suction pressure and suction
temperature measurements from the sensors that are
routed to the Chiller Control Board which in turn sends
control signals to the Flash Tank Drain and Fill Valve
Controller located in the left, back wall of the Chiller
Controls Cabinet.