Step 13 - Pumpdown & Evacuation; Evacuation And Recovery Of Refrigerant From Within 284Anv - Bryant 284ANV Installation Instructions Manual

284ANV: Installation Instructions
Step 13 – Pumpdown & Evacuation
Because this system has an inverter controlled compressor and EXV the
conventional procedure cannot be used to "pump down" and isolate the
refrigerant into the outdoor unit. The UI (User Interface) has provisions
to assist in performing this function. Pump Down
1. Connect gages to liquid and vapor or suction capillary service ports
to monitor operating pressures during and at completion of the
procedure.
2. In the "installation and service" menu of the UI (see
"refrigerant charging" and then "pump down" (see Figs. 11 & 12).
3. Select mode to pump down in (COOL or HEAT), COOL mode
allows refrigerant to be isolated in outdoor unit. HEAT mode
allows the refrigerant to be isolated in indoor coil and lineset. Set
desired time period. Default time period for the procedure is 120
minutes. See Fig. 21.
4. Select Start on UI to begin the pumpdown process. Unit will begin
running in selected mode after a brief delay and a status screen will
be displayed. See Fig. 22.
5. Close the liquid service valve.
6. The unit will run in selected mode with the low pressure protection
set to indicate pumpdown is complete when the suction pressure
drops below 20 psig. Compressor protections are still active to
prevent damage to the compressor or inverter (high pressure, high
current, etc.).
7. Once system indicates pumpdown complete or failure to complete
shutdown, close vapor service valve.
8. A recovery system will be required to remove final quantity of
refrigerant from indoor coil and line set.
9. Remove power from indoor and heat pump unit prior to servicing
unit.
NOTE: A small quantity of charge remains in the OD unit that must be
manually recovered if isolating refrigerant to indoor coil and lineset via
HEAT mode PUMP DOWN.
Fig. 21 – Pump Down Setup Screen
Fig. 22 – Pump Down Status Screen
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Evacuation and Recovery of Refrigerant from within
284ANV
Because this system has an EXV for the heating expansion device,
additional steps must be taken to open the EXV if the heat pump unit
must be evacuated for service reasons. If the EXV is not open when
pulling a vacuum or recovering refrigerant from the heat pump unit,
extended evacuation time may be required and/or inadequate vacuum
obtained. The UI (User Interface) has provisions to open the EXV for
refrigerant recovery and/or evacuation.
Fig. 10), go to
1. Connect gages to liquid and vapor or suction capillary service ports
to monitor operating pressures during and at completion of the
procedure. Attach recovery system or vacuum pump to gage set as
needed for the service procedure. The service valves must be open
to evacuate the unit through the line set service ports. The suction
capillary service port is a direct connection to the suction port of the
compressor.
2. In the "installation and service" menu of the UI (see
"refrigerant charging" and then "evacuation" (see
Fig. 12).
3. Set desired time period. Default time period for the procedure is
120 minutes. See
4. Select START on UI to open the valve.
5. Begin evacuation or refrigerant recovery as required for the
procedure after UI indicates the EXV is open. Power may be
removed from heat pump after the UI indicates "READY TO
EVACUATE." See
6. Remove power from indoor and heat pump unit prior to servicing
unit. The EXV will retain the open position.
NOTE: See service training materials for troubleshooting the EXV
using EXV CHECK mode.
A20040
A20041
11
Fig. 23.
Fig. 24.
Fig. 23 – Evacuation Setup Screen
Fig. 24 – Evacuation Status Screen
Fig. 10), go to
Fig. 11) and
A20042
A20043