Reznor MAPSII Series REDA Users Manual User Manual
Page 19
Form RZ-NA O-MAPS II, P/N 209179 R7, Page 19
tension counterclockwise until the spring tension is relieved.
Count and
record the number of turns required so that you can return the bypass
valve to its original setting.
Instructions for Checking and Adjusting the Superheat of an Isolated
Circuit:
Step 1) Measure and record the temperature (insulate probe from sur-
rounding air temperature) and the pressure of the suction line at the com-
pressor.
Step 2) From the Temperature/Pressure Conversion Chart on the left, con-
vert the pressure measured in
Step 1 to temperature.
Step 3) Subtract measured temperature in Step 1 from the temperature
taken from the Conversion Chart in
Step 2. The answer is the degrees of
superheat.
Recommended superheat range is 8-12°F (4.5-6.7°C).
Step 4) Superheat is adjusted at the thermal expansion valve. To reduce
superheat, turn the adjusting stem
counterclockwise. To increase the
superheat, turn the adjusting stem
clockwise. Adjust and check until
superheat is within the recommended range.
Step 5) Repeat Steps 1-4 for each refrigeration circuit.
Instructions for Checking and Adjusting the Subcooling of an Iso-
lated Circuit:
Step 1) Measure and record the temperature (insulate probe from sur-
rounding air temperature) and the pressure of the liquid line at the con-
denser coil outlet.
Step 2) From the Temperature/Pressure Conversion Chart on the previous
page, convert the pressure measured in
Step 1 to temperature.
Step 3) Subtract measured temperature in Step 1 from the temperature
taken from the Conversion Chart in
Step 2. The answer is the degrees of
subcooling.
Recommended subcooling range is 18-22°F (10.1-12.3°C).
Step 4) Subcooling is adjusted by the amount of refrigerant charge. To
reduce subcooling, remove refrigerant. To increase subcooling, add refrig-
erant. Adjust refrigerant and check until subcooling is within the recom-
mended range.
Step 12.
If the acid test in
Step 2 indicated a compressor burnout, do the following:
a) Operate the unit for several hours. Check the pressure drop through the
temporary suction line filter drier. If the pressure drop exceeds 8 psig,
recover the refrigerant, replace the suction line filter drier with the same
type as removed, replace the liquid line filter drier, evacuate the circuit, and
re-charge with the recovered refrigerant.
Continue to monitor the pressure drop through the suction line filter drier
and repeat the process above until the pressure does not exceed 8 psig
after several hours of operation.
b) Allow the system to operate for 4-8 hours. Recover the refrigerant and take
an oil sample. Retest the oil for acid.
c) If the test for acid is negative, remove the suction line filter drier, replace
the liquid line drier, evacuate, and re-charge the system with the recovered
refrigerant.
If the test indicates acid, replace both the liquid line filter drier and the suc-
tion line filter drier and repeat b) and c).
d) Verify subcooling and superheat (Refer to
Step 11.).
e) When the system is operating properly, remove the gauges.
IMPORTANT:
Do not release
refrigerant to the
atmosphere! If
required service
procedures
include the adding
or removing of
refrigerant, the
qualified HVAC
service technician
must comply with
all federal, state
or provincial, and
local laws.
Step 5) Repeat Steps 1) - 4 ) for each refrigeration circuit.