Position 3, curve with tripping: The pump will be cut out after 4
seconds if the rated current has been exceeded during this
time period.
Position 4, curve without tripping: The pump will not be tripped as
the current has only exceeded the nominal current briefly.
Note that the curves are examples and cannot be used for
readings.
6.15.5.2 Setting the trip class "P" with Grundfos GO Remote
1. Go to Settings > Motor protection pump 1.
2. Follow the on-screen instructions to set the nominal pump
current, trip class, overheat protection and cool-down time.
6.15.5.3 IEC trip classes
0.0
1
5
1010
50
100100
500
10001000
5000
10000
2
3
4
1
P
170
1.0 2.0 3.0
4.0 5.0 6.0 7.0 8.0
9.0
2.25
X
Y
TM072668
IEC trip curves
Pos. Description
Y Time [s]
X
x I
rated
P Class "P"
1 Class 30
2 Class 20
3 Class 10
4 Class 5
6.15.5.4 Setting the IEC trip classes with Grundfos GO Remote
Example:
At a motor current of 22.5 A (10 × 2.25), the pump is cut out after
approximately 170 seconds. In addition to IEC trip curves, a fixed
4 × I
rated
in 2 seconds is implemented to protect motors, especially
small ones, from overheating.
1. Go to Settings > Motor protection pump 1.
2. Follow the on-screen instructions to set the nominal pump
current, trip class and overheat protection.
6.15.6
Contactor Current Protection (CCP)
In addition, a Contactor Current Protection (CCP) trip class is
implemented to protect the internal contactors in the product from
overheating.
10000
1000
100
10
1
0.1 10 20 30 40 50 60 70 80
Y
2
X
1
TM072272
Example of CCP and class 30
Pos. Description
Y Trip time [s]
X Current [A]
1 CCP
2 CCP + Class 30
Example:
The full-load current is set to 10 A, and trip class 30 is selected.
• Motor overload: When the motor is overloaded with 15 A,
it takes approximately 800 seconds to trip the motor protection
when trip class 30 is selected.
• Blocked pump: If the pump is blocked and the motor has a
locked-rotor current specified to 65 A, it takes approximately
1 second to trip the motor protection due to CCP.
Contactor wear out
LC 23X has a wear-out counter for the contactor(s) based on the
actual current when the motor is switched off by the protection
function.
When 90 % of the estimated wear-out for the contactor is reached,
the warning code 220 appears on the operating panel. In Grundfos
GO Remote, the warning Contactor wear out appears. The control
unit continues to function.
When 100 % of the estimated wear-out for the contactor is reached,
the alarm code 220 Contactor wear out appears on the operating
panel and the control unit will not be able to start the
pumps. The control unit needs to be replaced.
Blocked pump
To prevent the contactor from getting worn out too fast if the pump
is blocked, a maximum number of restarts are allowed by
the control unit. Maximum number of blocked motor restart can
be set from 1 to 3 via Grundfos GO Remote. Tripped by the CCP-
curve. The alarm code 51 appears on the operating panel. In
Grundfos GO Remote, the alarm Blocked appears.
If the motor reaches the maximum number of restarts, from 1 to 3,
due to a blocked motor, it is possible to manually reset the failure up
to 3 times. After that, LC 23X waits 24 hours before trying to restart
the motor again. Alternatively, switch off the main power supply to
LC 23X for a minimum of 30 seconds to clear the alarms.
A blockage alarm is typically triggered when the motor starts
and the in-rush current trips the motor. The maximum allowed
blockage situations are limited to 6 times during a 24-hour period. If
the Maximum number of blocked motor restart is set to 3, the
control unit tries to restart the motor 3 times before a manual reset
is needed. If it occurs 3 times again after the reset, the control
unit reaches the maximum number of blockages.
Related information
6.15.4 Setting the motor protection with Grundfos GO Remote
17
English (GB)
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