Chilled Water Outlet Temperature Controller; Liquid Level Gauges; Start The Chiller; Stop The Chiller - York YHAU-CW Manual

FORM 155.31-ICOM2.EN.UL
ISSUE DATE: 12/21/2018
A drain trap does not need to be installed in the steam
drain line between the chiller and the hot well tank.
The presence of a drain trap will cause the steam flow
to become unstable. In this case, the condensed water
draining from the chiller is sub-cooled enough so that
a drain trap is unnecessary.
Isolate the main steam supply valve when servicing the
chiller or during an extended shut down.
CHILLED WATER OUTLET TEMPERATURE
CONTROLLER
The chilled water outlet temperature controller (23A)
is located on the sequencer. It controls the chilled wa-
ter outlet temperature.

Liquid Level Gauges

Liquid level gauges are used to check the condition of
the chiller components.

TABLE 24 - LIQUID LEVEL GAUGES

LIQUID LEVEL
SYMBOL
GAUGE NAME
Refrigerant overflow
G101
monitoring level gauge
Refrigerant tank level
G102
gauge
Absorber level gauge G103
HT-GEN level gauge G104
LT-GEN level gauge G105

START THE CHILLER

Before starting the chiller, inspect the following items:
• Check that the steam supply valve is open.
• Check the steam drain manual valve.
• Check that the refrigerant blow valve V8 is
closed.
• Open the steam shut off valve and keep the steam
inlet pressure at specification.
• Check that the Refrigerant Pump Auto button is
pressed.
After the review is complete, start the chiller.
JOHNSON CONTROLS
When the chiller starts, the following occurs:
FUNCTION
Checks refrigerant
overflow level
Checks lower limit of
refrigerant tank level

STOP THE CHILLER

Checks lower limit of
absorber
Checks condition
of solution in high-
temperature generator
Checks condition
When the chiller stops, the following occurs:
of solution in low-
temperature generator
SECTION 5 - COMMISSIONING
The OPER. and STOP buttons are avail-
able on the Main, Data, and Setting
screen. We recommend that you use these
buttons on the Main screen whenever
possible.
1. Navigate to the Main screen on the Control Panel.
2. Press the OPER. button on the Control Panel to
start the chiller. To start the chiller from a remote
location, enter the remote start signal.
• The solution circulation pump, solution spray
pump, and refrigerant pump start.
• The steam control valve or steam drain control
valve, steam drain solenoid valve, and steam
shut-off valve (option) open.
• The low drive source lamp lights and the low
opening of the control valve is held for about 10
minutes.
• After 10 minutes, the steam volume is controlled
automatically according to the cooling load and
the Temp. Control lamp lights.
1. Navigate to the Main screen on the Control Panel.
2. Press the STOP button on the Control Panel to
stop the chiller. To stop the chiller from a remote
location, enter the remote stop signal.
• The steam control valve or steam drain control
valve, steam drain solenoid valve , and steam
shut-off valve (option) close.
• The dilution operation starts and continues for 7
- 30 minutes.
• During the dilution operation, the solution circu-
lation pump, solution spray pump, and refrigerant
pump operate.
• Once the dilution operation is complete, the so-
lution circulation pump, solution spray pump,
and refrigerant pump stop. Then the chiller wa-
ter pump, cooling water pump, and cooling tower
stop.
• Close the steam supply manual valve and steam
drain manual valve.
5
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