Emerson Precision Cooling For Business-Critical Continuity Figure i - Manual (Page 23)

Installation
19
Remove Existing Condensing Unit
1. Recover refrigerant in system using proper refrigeration practices.
2. Oil removal: The majority of the oil will be in the old condensing unit (compressor, condenser and
receiver), which will be replaced with the new unit.
3. Remove high-voltage and low-voltage wiring.
4. Cut the line set before the Aeroquip fittings entering the condensing unit.
5. Remove the existing filter drier in evaporator unit and discard. The filter drier may contain
contaminants that can be released out of the drier because of the POE oil.
Filter Drier Selection and Installation
Recommended
1. Install a replaceable-core filter drier approved for POE oil. The existing drier must be removed.
The replaceable core drier will not fit in the same location as the existing drier.
2. Ensure there is enough clearance for replacing cores when choosing a location.
3. Replace core a week after startup and inspect the removed replaceable core for contaminants to
determine if another replacement is needed. (If the system experienced a burnout, shorter
interval replacements will be needed.)
Optional
Install a new filter drier approved for POE oil in place of the existing one.
Install the New Condensing Unit
1. Install a stub tube kit on the existing line set connecting to the new condensing unit. This kit is
available from Emerson or your local Emerson representative.
2. Evacuate the evaporator-piping system twice to a minimum 250 microns, breaking the vacuum
with dry nitrogen each time.
3. Evacuate a third time to 250 microns and verify the above levels are maintained for at least one
minute after the unit is isolated from the vacuum pump by a shutoff valve.
4. Connect the condensing unit with the evaporator and piping (see 2.5.4 - Installation of Piping
to Units).
5. Add enough R-407C refrigerant for the evaporator unit and line set. See Table 11 for line set
charges required and Table 12 for standard evaporator units. If a non-standard evaporator was
used, refer to evaporator unit serial tag for charge amounts and use 1 oz. (0.0283kg) R-407C for
every 1 oz. (0.0283kg) R-22 used in old evaporator and piping.
NOTE
Wiring should be removed by a licensed electrician.
Existing low-voltage wiring may have a 3-wire lead. A 4-wire lead is required for hot gas
bypass control on the new condensing unit.