Limit-Exceeded Function - Grundfos LCSE Installation And Operating Instructions Manual

7.15 "Limit-exceeded function"

Pump variant
LCSE
VLSE
This function can monitor a measured parameter or one of the
internal values such as speed, motor load or motor current. If a
set limit is reached, a selected action can take place. You can set
two limit-exceeded functions meaning that you can monitor two
parameters or two limits of the same parameter simultaneously.
The function requires setting of the following:
"Measured"
Here you set the measured parameter which is to be monitored.
"Limit"
Here you set the limit which activates the function.
"Hysteresis band"
Here you set the hysteresis band.
"Limit exceeded when"
Here you can set if you want the function to activate when the
selected parameter exceeds or drops below the set limit.
• "Above limit".
The function is activated if the measured parameter exceeds
the set limit.
• "Below limit".
The function is activated if the measured parameter drops
below the set limit.
"Action"
If the value exceeds a limit, you can set an action. You can select
the following actions:
• "No action".
The pump remains in its current state. Use this setting if you
only want to have a relay output when the limit is reached. See
section
7.9 "Signal relays" 1 and 2 ("
• "Warning/alarm".
A warning is given.
• "Stop".
The pump stops.
• "Min.".
The pump reduces speed to minimum.
• "Max.".
The pump increases speed to maximum.
46
"Limit-exceeded
function"
●
●
Relay outputs"
).
Detection delay
You can set a detection delay which ensures that the monitored
parameter stays above or below a set limit in a set time before the
function is activated.
Resetting delay
The resetting delay is the time from which the measured
parameter differs from the set limit including the set hysteresis
band and until the function is reset.
Example:
The function is to monitor the outlet pressure from a CRE pump.
If the pressure is below 5 bar for more than 5 seconds, a warning
must be given. If the outlet pressure is above 7 bar for more than
8 seconds, reset the limit exceeded warning.
1
2
4 4
A
5
Fig. 66 Limit exceeded (example)
Pos. Setting parameter
1 "Measured"
2 "Limit"
3 "Hysteresis band"
4 "Limit exceeded when"
5 "Detection delay"
6 "Resetting delay"
A "Limit exceeded function active" -
- "Action"
Factory setting
See section
10. Technical data.
3
Time [s]
6
Setting
Outlet pressure
5 bar
2 bar
Below limit
5 seconds
8 seconds
Warning