Just Better SH-35N Superheat Subcooling - Manual (Page 4)

REFRIGERATION APPLICATIONS
SETTING FOR THERMOSTAT
CONTROLLED CASES AND
COOLERS
Without plug-ins, turn on the gauge
and zero the display by holding
the lower button. Plug in the
Temperature Sensor only and toggle
to “Temperature.”
SETTING FOR THERMOSTAT
CONTROLLED CASES AND
COOLERS
Without plug-ins, turn on the gauge
and zero the display by holding the
lower button. Attempts to zero the
gauge with pressure applied will
result in (Err) display.
A/C & REFRIGERATION APPLICATIONS
Contact your TXV manufacturer for the exact superheat adjust rate.
0 5 10 15 20 25
20
18
16
14
12
10
8
6
4
Superheat
ϒF
Time in Minutes
Expansion Valve Superheat
SH-35N Average Superheat Hussmann RHF A 4 Door FF Case
1 Ton Lo w Temp. TXV
-2 F Case Temperature
40% Heater Load
SET SUPERHEAT FOR
“HUNTING” TXV VALUES
In refrigeration and air
conditioning systems, the
expansion valve often
operates to produce an
evaporator superheat
which constantly swings up
and down in value, called
“hunting.” The SH-35N
provides the “Average”
superheat value for TXV
valve adjustment.
CHECKING TXV SETTING
The objectives of the TXV superheat setting is to prevent
liquid refrigerant floodback to the compresor and to
optimize system operation by the use of a selected setting.
The two temperature method of measuring superheat
is not recommended because it can produce a wrong
superheat measurement, due to the effect of temperature
glide of the blended refrigerants and variations in
evaporator pressure drop.
NEW RESIDENTIAL A/C SYSTEMS
For new installations of residential A/C systems, the pre-
charge will not provide an accurate amount of refrigerant
charge because of the variation in the length of liquid and
suction line connecting to the “A” coil.
RETROFITTING SYSTEMS
Retrofitting systems to a new refrigerant can change the
TXV superheat setting. The superheat setting should
be checked before and after retrofitting to be sure the
superheat is right for the equipment.
REPLACEMENT ITEMS
PART NO. DESCRIPTION
A34000 1/4" QC x 1/4" Access Branch Tee
SH-54 6' Temperature Sensor
SH-55 Plastic Carrying Case
SH-56 Socks (5)
ACCESSORIES
SH-51 28' Temperature Sensor Extension
KEY REFRIGERANT LIST
R12
R134a
R290
R401A
R401B
R402A
R402B
R403B
R404A
R406A R407A
R407B
R407C
R408A
R409A
R410A
R411C
R413A
R414B
R416A
R417A R422A
R422B
R422C
R422D
R427A
R428A
R438A
R502
R507
R508B
SUPERHEAT
JB INDUSTRIES
630.851.9444
Printed in USA
Part No. 10737-308 © 2011 J/B Industries Inc.
Technical service: 800-323-0811
E-Mail:[email protected]
Web Site:www.jbind.com
Fahrenheit and Celsius Keys are not interchangeable
SUPERHEAT
TEMPERATURE
SENSOR
TEMP PSI