Grundfos E-pumps

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Grundfos E-pumps
Advanced use of MLE motors
Limit exceeded 1 and 2
Limit exceeded is a monitoring function monitoring one
or two values/inputs. The function enables different
inputs to activate various outputs and alarms/
warnings when the signal input has exceeded
pre-determined limits.
Input
Fig. 83 Example of a "limit exceeded" sequence
Purpose and benefits
The purpose of this function is to monitor parameters
which are central for the application. This will enable
the controller to react to possible, abnormal operating
conditions. This makes the E-pump a more important
and integrated part of a system, and it can thus replace
other existing monitoring units.
The liquid temperature can be monitored, and thus the
E-pump can ensure that the system temperature does
not exceed a maximum permissible level.
The minimum inlet pressure can be monitored, and
thus the E-pump can prevent damage caused by a
cavitation or dry run.
Applications
The limit exceeded function is typically used for
monitoring secondary parameters in the systems.
This function is available in these pump sizes:
2-pole
[Hp]
Limit exceeded
Single-phase pumps
Outputs
Alarm/warning
4-pole
[Hp]
0.50 - 1.5 0.33 - 1.0
- -
Three-phase pumps
2-pole
[Hp]
1.0 - 10 15 - 30
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TM03 9188 3507
Description
The figures below show two examples of setpoint monitoring
by means of the limit exceeded function.
Monitored value = feedback value
Limit
Setpoint
Action
Not active
Detection
delay
Fig. 84 Limit exceeded sequence with the limit type
"max. limit", for example monitoring of bearing
temperature
Monitored value = feedback value
Setpoint
Limit
Action
Not active
Detection
delay
Reset hysteresis
Active
Reset hysteresis
Active
Reset delay
Reset delay
Fig. 85 Limit exceeded sequence with the limit type
"min. limit"
When the limit is exceeded, the signal input crosses
the limit as an increasing or decreasing value, and the
function can be set to cover both situations.
TM03 9197 3607
TM03 9196 3607
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