Reznor MAPSII Series REDA Users Manual - Manual (Page 16)

Form O-MAPS II, P/N 209179 R7, Page 16
FIGURE 9 -
Pressure Rise
vs Time
IMPORTANT
NOTE:
Always check
gauge hose
connections
for leaks prior
to evacuation.
 Step 8. Check the Electrical System
While the system is being evacuated, connect the electrical plug to the
compressor. It is a normal practice to replace all starting components any
time a compressor is changed.
WARNING: Voltage should not be applied to the compressor
when the terminal plug is removed as personal injury could
result.
Compressor
Maintenance
Checklist,
Steps 1-13 (cont'd)
If there is a crankcase heater, connect it. The crankcase heater is ener-
gized continuously and is extremely important to proper compressor oper-
ation and long life.
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
2,200
2,400
-20 0 20 40 60 80 100 120
Time (minutes)
Pressure (microns)
Evacuate to 500 microns or lower.
If system holds a vacuum at or below 700 microns,
the system is sufficiently dry and has no leaks.
If system holds a steady vacuum in
this region, there are no leaks. But
the system is not sufficiently dry. Re-
evacuate to remove excess moisture.
If system pressure continues
to rise, the system has leaks.
The leaks must be found and
sealed prior to re-evacuating.
Time varies by moisture level.
 Step 7. Evacuate the System
Use a vacuum pump rated for a minimum capacity of 6 cfm. Vacuum must
be pulled on both the discharge (high) and suction (low) sides of the sys-
tem. Evacuate to 500 microns or lower.
Moisture and air are harmful to the system because they increase the con-
densing temperature, raise the discharge gas temperature, cause forma-
tion of acids, and cause oil breakdown.
CAUTION: Do not use the replacement compressor as an
evacuation assist and never apply voltage to a compressor while
it is in a vacuum.
Acids are corrosive to the components in the refrigeration system. This
includes the piping, refrigerant specialties, and the compressor’s mechani-
cal and electrical components. The elevated temperatures can cause cop-
per plating resulting in premature mechanical failure of the compressor.
To establish that the unit is leak-free and moisture-free, a standing vacuum
test is recommended. The maximum allowable rise over a 18-minute
period is 200 microns. If the rise exceeds this, either there is a leak or
moisture still exists in the system. See the chart in FIGURE 9.
7.0 Compressor
Maintenance
and
Replacement
(cont'd)