FORM 201.10-NM4
127
YORK INTERNATIONAL
q
2. Record the suction temperature, suction pres-
sure, suction pressure converted to temperature,
and superheat of each system below:
SYS 1 SYS 2 SYS 3 SYS 4
Suction Temp = _____ _____ _____ _____ °F
Suction Press = _____ _____ _____ _____ PSIG
Temp = _____ _____ _____ _____ °F
Superheat = _____ _____ _____ _____ °F
CHECKING ECONOMIZER SUPERHEAT
(15 TON TXV)
The economizer superheat should be checked to as-
sure proper economizer operation and motor cooling.
Correct superheat setting is approx. 10 - 15°F.
The superheat is calculated as the difference between
the pressure at the Economizer Service Valve on the
compressor converted to the corresponding tempera-
ture in a standard pressure/temperature chart and tem-
perature of the gas at the bulb on the entering piping to
the motor housing.
Example:
Motor Gas Temp =
90°F
minus Economizer Press
139 PSIG converted
to Temp
- 78°F
12°F
Normally, the thermal expansion valve need not be ad-
justed in the field. If, however, adjustment needs to be
made, the expansion valve adjusting screw should be
turned not more than one turn at a time, allowing suffi-
cient time (approximately 15 minutes) between adjust-
ments for the system and the thermal expansion valve
to respond and settle out. Assure that superheat is set
between 10 -15°F.
q
1. Record the motor gas temperature, economizer
pressure, economizer pressure converted to
temperature, and economizer superheat below:
SYS 1
SYS 2
SYS 3
SYS 4
Motor Gas Temp = _____
_____
_____
_____
PSIG
Economizer Press = _____
_____
_____
_____
°F
Economizer Temp = _____
_____
_____
_____
°F
Superheat = _____
_____
_____
_____
°F
NOTE: This superheat should only be checked in an
ambient above 90°F. Otherwise, mid-range ad-
justment (factory setting) is acceptable.
5 TON TXV SUPERHEAT SETTING
The 5 Ton TXV Superheat does not require checking. It
should typically operate at 10 - 15°F. Since it is difficult
to check, the factory set “mid-range adjustment” is ac-
ceptable.
LEAK CHECKING
q
1. Leak check compressors, fittings, and piping to
assure there are no leaks.
If the unit is functioning satisfactorily during the initial
operating period, no safeties trip and the compressors
load and unload to control water temperature, the chiller
is ready to be placed into operation.
