Pfeiffer Vacuum A 1204H, Operating Instructions Manual

Page: 36 / 92

36
Advanced settings
7.1.2 Indicating a nitrogen flow defect
3 monitoring thresholds and a delay linked to each threshold can be set in menu [SET-
TING] [PURGE] [PURGE FLOW] then[PRE-WARNING]/[WARNING]/[PRE-ALARM]
(see 8.2) .
If the measured flow of nitrogen is lower than the set threshold, a fault appears after the
expiry of a time delay.
None of these defects stops the pump .
The [PRE-ALARM] can’t be set to [DISABLED] neither be modified.
7.1.3 Prolonging the purge
The system is automatically purged when the pump stops (normal stop or stop due to
defect) if the system is set to maintain the purge gas.
But it is not purged if the pumps stops in case of an alarm of exhaust pressure D01 or
emergency stop D34.
Program [SETTING] [PURGE] [PURGE PROLONG] [DELAY] according to the process
(see 8.2) or see Serial link Operating instructions.
T
1
0
T
Purge valve
Pump
START STOP PURGE PURGE PURGE Time
WARNING
Risk due to process gases
It is highly recommended not to stop the purge when the pump is running.
Nitrogen flow
Time
T
pre-warning
Pre-warning
threshold
Warning threshold
No message
T
pre-alarm
Pre-alarm message
T
warning
Pre-alarm threshold
Pre-warning message
Warning message
Time
T
1
0
Purge
Pump
START STOP