Reznor MASA Unit Installation Manual - Manual (Page 33)

Form I-COND, P/N 220746R6, Page 33
CAUTION
Crankcase heaters must be allowed to warm up for at least
24 hours prior to startup. Disable cooling controls before
turning on power to warmup crankcase heaters. See Hazard
Levels, page 3.
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Step 9. Charge the System (R-410A refrigerant)
Charge the circuit according to the information in Paragraph 6.4. R-410A
refrigerant must be charged as a LIQUID.
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Step 10 . System Startup
Connect refrigerant pressure gauges and electric meters. Refer to Start-Up
Paragraph 9.2 and perform all procedures required prior to checking sub-
cooling and superheat which is done in Step 11.
CAUTION
Be sure to connect pressure gauges to the suction and
discharge lines before start-up so that compressor rotation
can be checked immediately. Scroll compressors will be
destroyed if allowed to operate in reverse. See Hazard Levels,
page 3.
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Step 11. Check Subcooling and Superheat
Refer to Start-Up Paragraph 9.2 and follow instructions for checking sub-
cooling and superheat.
WARNING
Do not release refrigerant to the atmosphere. When adding or
removing refrigerant, the qualified technician must comply
with all national, state/province, and local laws.
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Step 12. (Select the procedure that applies.)
IF the oil measured in Step 2 was significantly less than in TABLE 10
or the acid test in Step 2 indicated a 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 (see Paragraph 6.4).
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. (NOTE: System must be allowed to run
no more than 72 hours with a suction line filter drier.)
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 recov-
ered refrigerant.
If the test indicates acid, replace both the liquid line filter drier and the
suction line filter drier and repeat b) and c).