VWR VP 820 Manual Del Usuario página 10

English
Switching off the pump/removing from operation
 Purge the pump including the connecting hoses with air (if necessary for safety reasons: with an inert
gas) at full flow rate for about 5 minutes (see chapter 8.2.1).
 If the drying system is switched on: Switch the drying system off at the main switch of the control box
(see fig. 2).
 Switch off pump with mains switch (see fig. 2).
 Open pressure and suction lines to normal atmospheric pressure.
 Disconnect the power source.
7.4 Drying system: Changing settings
The variables of the drying system can be adapted to a process sequence.
Drying system control box
t : Time between switching on the drying system and the first ventilation of the pump heads

1
 t : Duration of the ventilation of the pump heads.
2
t : The interval between pump head ventilation operations.

3
Switch setting Switch 1
t in sec
1
0 t
3
1 60.0
2 90.0
3 120.0
4 150.0
5 180.0
6 210.0
7 240.0
8 300.0
9 360.0
Tab. 5: Variables and values
Switch
1
2
3
Tab. 6: Work setting
Changing settings
Extreme danger from electrical shock!
 Disconnect the pump power supply before working
on the pump.
 Make sure the pump is de-energized and secure.
DANGER
1. Disconnect the pump from the mains by pulling the plug out of
the socket.
2. Check that the pump and the drying system are dead and secure them.
3. At the control box, loosen the collar nut of the cable inlet. Use a slotted screwdriver to release the four
screws, then fold the cover forwards and lay it down (see fig. 4).
The control box may only be opened if there is no risk of moisture precipitating on the control unit.
4. Set the desired values at switches S1, S2, and S3 (see fig. 4). See Table 5 for an explanation of the
switches and for the values which can be set.
5. Replace the cover on the control box. Take care to ensure that the seal is properly in place. Tighten the
four screws of the cover to finger tightness. Then tighten the collar nut of the cable inlet.
10
Switch 2
t in sec
2
1.0
1.5
2.0
2.5
3.0
3.5
4.0
5.0
7.5
10.0
Switch setting
6
2
3
Switch 3
t in sec
3
10.0
15.0
25.0
40.0
60.0
120.0
180.0
300.0
600.0
900.0
Time in sec
210.0
2.0
40.0
.
Fig. 4: Control box (opened) of
drying system with
switches 1, 2, 3
Fig. 5: Switch for setting the drying
system