Waters Prep Series Installation And Maintenance Manual page 119

• The Hold output (on the controller's rear panel) activates, signaling the
connected instrument (for instance, the autoinjector) that the system is
not ready for operation.
• Gradient, Event, and Detector tables that were running abort.
• The Autostart time and Table # fields reset to blank.
• External output switches S1 to S4, sparge valves, and the Alarm remain
in their current state, on or off.
• Sparging continues at the last entered sparge rate.
• The shutdown message remains on the screen until you press CLEAR.
When the stop flow signal occurs
If a signal is detected at the Stop Flow terminal during a shutdown, a message
appears on the screen. An inject input is not recognized while the system is in
shutdown.
If the cause is an obviously a system component, remove the component from
the system. Then continue as follows.
Shutdown not caused by stop flow signal
If a Stop Flow signal does not cause the shutdown, or if you correct the
problem, press CLEAR to resume operation. Also take these actions where
applicable:
• For isocratic operation, enter the flow rate
• For gradient operation, press the RESUME key to resume operation
where the failure stopped it.
Another shutdown can occur if you do not correct the cause before restarting.
The controller only recognizes the first shutdown cause. Subsequent
Tip:
shutdown conditions are ignored once shutdown occurs.
Shutdown messages
Message
Low Pressure Limit The value entered on the SETUP screen was not
Description
maintained. If the low-pressure limit was set high,
check for small leaks at fittings and unions.
Shutdowns with low limit settings are caused by
large noticeable failures or an empty solvent
reservoir.
Troubleshooting 3-35