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Charging In Cooling Mode - 25VNA024/036
See user interface set in Charging Mode
Heating Check Chart - 25VNA024/036
For use in Heating Charging Mode only
400
350
Vapor Service
Valve Pressure
300
250
200
150
100
Suction Pressure
50
0
0
10
20
30
(-18ºC)
(-12ºC)
(-7ºC)
(-10ºC)
Outdoor Ambient Temperature ºF (ºC)
25VNA024/036 Heating Pressure check Chart (Psig)
Indoor Temperature (_F)
OD DB
60
(_F)
High
Low
60
290
129
50
263
106
40
245
89
30
232
74
20
222
69
10
212
55
0
203
49
Fig. 12 - - Heating Pressure Check Chart 25VNA024/036
Step 14 — Pumpdown & Evacuation
If this system requires either a Pump Down or Evacuation for any
reason, the procedures below must be followed:
Pump Down
Because this system has an inverter controlled, compressor, suction
pressure transducer and EXV, 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.
1. Connect gages to 25VNA liquid and vapor or suction capil-
lary service ports to monitor operating pressures during and
at completion of the procedure.
2. In the advanced menu of the UI, go to Checkout > Heat
Pump> Pumpdown
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 peri-
od for the procedure is 120 minutes.
4. Select Start on UI to begin the pumpdown process. Unit
will begin running in selected mode after a brief delay.
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 0 psig. Compressor protec-
tions are still active to prevent damage to the compressor or
inverter (high pressure, high current, high torque, scroll
temperature, etc.) .
7. Once system indicates pumpdown complete or failure to
complete shutdown, close vapor service valve.
8. If pumpdown does not complete due to compressor safety
shutdown, a recovery system will be required to remove fi-
nal quantity of refrigerant from indoor coil and line set.
9. Remove power from indoor and heat pump unit prior to ser-
vicing unit.
40
50
60
(4ºC)
(10ºC)
(16ºC)
70
80
High
Low
High
Low
329
130
368
132
303
108
346
110
285
90
324
90
270
81
312
87
256
68
291
64
246
52
281
53
238
43
270
50
2757
450
2413
400
Vapor Service
350
2068
Valve Pressure
300
1724
250
1380
200
1034
150
690
100
Suction Pressure
345
50
0
0
0
10
(-18ºC)
(-12ºC)
A11140
25VNA048/060 Heating Pressure check Chart (Psig)
OD DB
(_F)
High
60
324
50
293
40
277
30
257
20
242
10
232
0
218
Fig. 13 - - Heating Pressure Check Chart 25VNA048/060
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.
Evacuation and Recovery of Refrigerant from within
25VNA
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.
provisions to open the EXV for refrigerant recovery and/or
evacuation.
1. Connect gages to 25VNA liquid and vapor or suction capil-
lary 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 proced-
ure. The service valves must be open to evacuate the unit
through the line set service ports. The suction capillary ser-
vice port is a direct connection to the suction port of the
compressor.
2. In the advanced menu of the UI, go to Checkout > Heat
Pump> > Evacuation.
3. Set desired time period. Default time period for the proced-
ure is 120 minutes.
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."
6. Remove power from indoor and heat pump unit prior to ser-
vicing unit. The EXV will retain the open position.
NOTE: See service training materials for troubleshooting the
EXV using EXV CHECK mode.
11
Charging In Cooling Mode - 25VNA048/060
See user interface set in Charging Mode
Heating Check Chart - 25VNA048/060
For use in Heating Charging Mode only
20
30
40
50
(-7ºC)
(-10ºC)
(4ºC)
(10ºC)
Outdoor Ambient Temperature ºF (ºC)
Indoor Temperature (_F)
60
70
Low
High
Low
121
360
120
99
333
100
87
307
80
69
288
65
57
281
60
50
263
47
42
253
43
The UI (User Interface) has
3102
2757
2413
2068
1724
1380
1034
690
345
0
60
(16ºC)
A11141
80
High
Low
407
121
380
102
360
88
333
69
320
60
306
50
288
42
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