User Guide

59
English (US)
11.3 Fault finding table
Warning and alarm codes Fault
Automatic reset
and restart
Corrective actions
"Pump communication fault"
(10)
"Alarm"
Communication fault between
different parts of the
electronics.
Yes
Contact Grundfos Service, or replace the pump.
Check if the pump is running in turbine
operation. See code (29) "Forced pumping".
"Forced pumping" (29)
"Alarm"
Other pumps or sources force
flow through the pump even if
the pump is stopped and
switched off.
Yes
Switch off the pump on the main disconnect
switch. If the light in Grundfos Eye is on, the
pump is running in forced-pumping mode.
Check the system for defective check valves
and replace the valves, if necessary.
Check the system for correct position of check
valves, etc.
"Undervoltage" (40, 75)
"Alarm"
The supply voltage to the pump
is too low.
Yes
Make sure that the power supply is within the
specified range.
"Blocked pump" (51)
"Alarm"
The pump is blocked. Yes
Dismantle the pump, and remove any foreign
matter or impurities preventing the pump from
rotating.
"High motor temperature" (64)
"Alarm"
The temperature in the stator
windings is too high.
No Contact Grundfos Service, or replace the pump.
"Internal fault" (72 and 155)
"Alarm"
Internal fault in the pump
electronics.
Irregularities in the voltage
supply can cause alarm 72.
Yes
There might be turbine flow in the application
that forces a flow through the pump.
Check if the sensor is blocked by sediments.
This can occur if the media is impure.
Replace the pump, or contact Grundfos Service.
"Overvoltage" (74)
"Alarm"
The supply voltage to the pump
is too high.
Yes
Make sure that the power supply is within the
specified range.
"Comm. fault, twin-head pump"
(77)
"Warning"
The communication between
pump heads was disturbed or
broken.
-
Make sure that the second pump head is
powered on or connected to the power supply.
"Internal fault" (84, 85 and 157)
"Warning"
Fault in the pump electronics. - Contact Grundfos Service, or replace the pump.
"Internal sensor fault" (88)
"Warning"
The pump is receiving a signal
from the internal sensor which
is outside the normal range.
-
Make sure that the plug and cable are
connected correctly in the sensor. The sensor is
located on the back of the pump housing.
Replace the sensor, or contact Grundfos
Service.
"External sensor fault" (93)
"Warning"
The pump is receiving a signal
from the external sensor which
is outside the normal range.
-
Does the electrical signal set (0-10 V or 4-20
mA) match the sensor output signal?
If not, change the setting of the analog input, or
replace the sensor with one that matches the
setup.
Check the sensor cable for damage.
Check the cable connection at the pump and at
the sensor. Correct the connection, if required.
The sensor has been removed, but the analog
input has not been disabled.
Replace the sensor, or contact Grundfos
Service.
Warnings do not activate the alarm relay.