Normally, the thermal expansion valve need not be
adjusted 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
sufficient time (approximately 15 minutes) between
adjustments for the system and the thermal expansion
valve to respond and settle out. Assure that superheat is
set between 10 - 12°F (6 - 7°C).
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
Economizer Gas
Temp =
PSIG (kPa)
Economizer
Press =
°F
(°C)
Temp =
°F
(°C)
Superheat =
°F
(°C)
This superheat should only be checked
in an ambient above 90°F (32°C).
Otherwise, mid-range adjustment (fac-
tory setting) is acceptable. Below 90ºF
(32ºC) ambient, the economizer will
not provide additional subcooling.
LEAk CHECkIng
1. Leak check compressors, fittings, and piping to
assure 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.
©2009 Johnson Controls, Inc.
P.O. Box 423, Milwaukee, WI 53203
www.johnsoncontrols.com
Printed in USA 201.19-CL2 (309)
New Release
