Expansion Valve Adjustment - Hussmann INSIGHT REACH-IN Installation & Operation Manual

EXPANSION VALVE ADJUSTMENT

Expansion valves must be adjusted to fully feed the evaporator. Before
attempting to adjust valves, make sure the evaporator is either clear or
only lightly covered with frost, and that the merchandiser is within 10
deg F (6.5 deg C) of its expected operating temperature. Adjust valves
as follows:
NOTE
When using high glide refrigerants (e.g., R-407A, R-448A), use the
evaporator pressure and subtract the dew point from the coil outlet
refrigerant temperature to measure the superheat level.
Method 1 (recommended):
Attach a sensing probe (either thermocouple of thermistor) to the
evaporator outlet, under the clamp holding the expansion valve
bulb. Attach a pressure probe to the access valve on the suction line.
Measure superheat by subtracting the saturation temperature at the
measured pressure from the measured outlet temperature.
Method 2:
Attach two sensing probes. Attach two sensing probes (either thermocouple
or thermistor) to the evaporator. Position one under the clamp holding
the expansion valve bulb; securely tape the other to the coil inlet line.
Some "hunting" of the expansion valve is normal. The valve should be
adjusted so that during the hunting the greatest difference between the
two probes is 3–5 deg F (1.7–2.8 deg C). With this adjustment, during
a portion of the hunting the temperature difference between the probes
SENSOR-COIL INLET LOCATION
STANDARD COIL & DISTRIBUTOR (AS PURCHASED)
will be less than 3 deg F (1.7 deg C) and at times 0.
2 & 3 DOOR CASES
ISO VIEW ROTATED 130° CCW
SCALE 1: 2
Make adjustments of no more than ¼ turn for Balanced Port TEV
and ½ turn at a time for other valve models. Wait at least 15
TUBE 3/8 ID VINYL
minutes before re checking the probe temperature or making further
adjustments.
(INSULATION-
SENSOR-COIL INLET LOCATION
CO2 COIL & TUBE MODULE (2 & 3 DOOR CASES)
HUSSMANN CORPORATION • U.S. & CANADA 1-800-922-1919 • BRIDGETON, MO 63044-2483 • MEXICO 1-800-890-2900 • WWW.HUSSMANN.COM • PN 3181178_A
ISO VIEW ROTATED 105° CCW
SENSOR-COIL INLET
ON MIDDLE COIL TUBE
SENSOR-COIL INLET LOCATION
STANDARD COIL & DISTRIBUTOR (AS PURCHASED)
2 & 3 DOOR CASES
ISO VIEW ROTATED 130° CCW
SCALE 1: 2
TUBE 3/8 ID VINYL
G
(INSULATION-
SENSOR-COIL INLET LOCATION
CO2 COIL & TUBE MODULE (2 & 3 DOOR CASES)
ISO VIEW ROTATED 105° CCW
SCALE 1:2
SCALE 1:2
SENSOR-COIL INLET LOCATION
STANDARD COIL & DISTRIBUTOR (AS PURCHASED)
2 & 3 DOOR CASES
ISO VIEW ROTATED 130° CCW
SCALE 1: 2
Coil Inlet Sensor Location
TUBE 3/8 ID VINYL
CO₂ Coil & Tube 2 & 3 Door Cases
(INSULATION-
SENSOR-COIL INLET LOCATION
SENSOR-COIL INLET
ON MIDDLE COIL TUBE CO2 COIL & TUBE MODULE (2 & 3 DOOR CASES)
ISO VIEW ROTATED 105° CCW
Coil Inlet
SENSOR-COIL INLET
ON SECOND COIL TUBE
Sensor on
Second Coil
Tube
SENSOR-COIL INLET LOCATION
STANDARD COIL & DISTRIBUTOR (AS PURCHASED)
ISO VIEW ROTATED 90° CCW
TUBE 3/8 ID VINYL
G
Coil Inlet Sensor Location
CO₂ Coil & Tube 4 & 5 Door Cases
(INSULATION-
1.125 ID X 0.500 WALL)
SENSOR-COIL INLET LOCATION
CO2 COIL & TUBE MODULE (4 & 5 DOOR CASES)
ISO VIEW ROTATED 105° CCW
2-5
Coil Inlet Sensor on
SENSOR-COIL INLET
ON MIDDLE COIL TUBE
Middle Coil Tube
SENSOR-COIL INLET LOCATION
Coil Inlet Sensor Location
STANDARD COIL & DISTRIBUTOR (AS PURCHASED)
2 & 3 DOOR CASES
Standard Coil & Distributor 2 & 3-Door Cases
ISO VIEW ROTATED 130° CCW
SCALE 1: 2
3/8" Tube
TUBE 3/8 ID VINYL
G
Insulation
(INSULATION-
SENSOR-COIL INLET LOCATION
CO2 COIL & TUBE MODULE (2 & 3 DOOR CASES)
ISO VIEW ROTATED 105° CCW
SENSOR-COIL INLET
ON SECOND COIL TUBE
SCALE 1:2
Coil Inlet Sensor Location
Standard Coil & Distributor 4 & 5-Door Cases
SENSOR-COIL INLET LOCATION
STANDARD COIL & DISTRIBUTOR (AS PURCHASED)
4 & 5 DOOR CASES
ISO VIEW ROTATED 90° CCW
4 & 5 DOOR CASES SCALE 1: 2
SCALE 1: 2
3/8" Tube
TUBE 3/8 ID VINYL
Insulation
(INSULATION-
1.125 ID X 0.500 WALL)
SENSOR-COIL INLET LOCATION
CO2 COIL & TUBE MODULE (4 & 5 DOOR CASES)
ISO VIEW ROTATED 105° CCW
SCALE 1:2
SCALE 1:2
SENSOR-COIL INLET
ON MIDDLE COIL TUBE
SENSOR-COIL INLET
ON SECOND COIL TUBE
STANDA
G
TUBE 3/8 ID VINYL
(INSULATION-
SCALE 1:2
1.125 ID X 0.500 WALL)
CO2