Leak Checking - York YCAL0019 Installation, Operation And Maintenance Manual

FORM 150.67-NM1
ISSUE DATE: 4/28/2017
 1. Record the liquid line pressure and its correspond-
ing temperature, liquid line temperature and
subcooling below:
Liq Line Press = _______ _______ PSIG
Saturated Temp = _______ _______ °F
Liq Line Temp = _______ _______ °F
Subcooling = _______ _______ °F
After the subcooling is verified, the suction superheat
should be checked. The superheat should be checked
only after steady state operation of the chiller has been
established, the leaving water temperature has been
pulled down to the required leaving water temperature,
and the unit is running in a fully loaded condition. Cor-
rect superheat setting for a system is 10 °F to 15 °F
(5.56 °C to 8.33 °C) 18" (46 cm) from the heat ex-
changer.
Superheat should typically be set for no less than 10
°F with only a single compressor running on a cir-
cuit. The superheat is calculated as the difference be-
tween the actual temperature of the returned refrigerant
gas in the suction line entering the compressor and the
temperature corresponding to the suction pressure as
shown in a standard pressure/temperature chart.
Example:
Suction Temp =
Minus Suction Press
105 PSIG converted to Temp - 34 °F
Superheat =
JOHNSON CONTROLS
SYS 1 SYS 2
46 °F
12 °F
When adjusting the expansion valve (TXV only), the
adjusting screw should be turned not more than one
turn at a time, allowing sufficient time (approximately
15 minutes) between adjustments for the system and
the thermal expansion valve to respond and stabilize.
Assure that superheat is set at a minimum of 10 °F (5.56
°C) with a single compressor running on each circuit.
 2. Record the suction temperature, suction pressure,
suction saturation temperature, and superheat of
each system below:
Suction Temp = _______ _______ °F
Suction Pressure = _______ _______ PSIG
Saturation Temp = _______ _______ °F
Superheat = _______ _______ °F

LEAK CHECKING

 1. Leak check compressors, fittings, and piping to
ensure no leaks.
If the unit is functioning satisfactorily during the ini-
tial operating period, no safeties trip and the compres-
sors cycle to control water temperature to setpoint, the
chiller is ready to be placed into operation.
SECTION 6 – COMMISSIONING
SYS 1 SYS 2
151
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