Grundfos CU 321 User Manual

22
5.5 Description of warning and alarm codes
Code LED Description
2
Yellow
Sensor output out of range
The current signal on terminal 60 is below 4 mA.
The pump will stop in case of warning 2.
4
AC line phase fault
Missing mains phase on AC line supply side.
Check the supply voltage to the CU 321.
(This fault is only active in 3-phase 5 hp CU 321).
5
Yellow
Voltage warning high
If the voltage is higher than the Voltage warning high limit, the CU 321 will give a warning and
the motor will continue to operate unchanged.
The Voltage warning high limit is: 285 V
AC
.
Check whether the supply voltage matches the rating of the CU 321, see section 6. Technical
data.
Note: An alarm code 7 (overvoltage) will occur if the voltage remains above the Voltage warn-
ing high limit for a fixed period of more than 5 seconds.
6
Yellow
Voltage warning low
If the voltage is lower than the Voltage warning low limit, the CU 321 will give a warning and
the motor will continue to operate unchanged.
The Voltage warning low limit is: 170 V
AC
.
Check whether the supply voltage matches the rating of the CU 321, see section 6. Technical
data.
Note: An alarm code 8 (undervoltage) will occur if the voltage remains below the Voltage
warning low limit for a fixed period of more than 5 seconds.
When the CU 321 is switched off, warnings 6 and 8 are displayed briefly.
7
Red
Overvoltage
If the voltage is higher than the Overvoltage limit, the CU 321 will cut out until the voltage falls
below the Overvoltage limit.
Note: An alarm code 7 (overvoltage) will occur if the voltage remains above the Overvoltage
limit for a fixed period of more than 5 seconds. The time depends on the unit and is factory-set
to 5 seconds.
Voltage warning high (warning 5) will be able to generate an alarm 7.
8
Red
Undervoltage
If the voltage is lower than the Undervoltage limit, the CU 321 will cut out until the voltage
once more rises above the Undervoltage limit.
Check the supply voltage to the CU 321, see section 6. Technical data.
Note: An alarm code 8 (undervoltage) will occur if the voltage remains below the Under-
voltage limit for a fixed period of more than 5 seconds. The time depends on the unit and is
factory-set to 5 seconds.
When the CU 321 is switched off, an alarm 8 and warning 6 are displayed briefly and a alarm
reset is generated.
Note: Voltage warning low (warning 6) will be able to generate an alarm 8.
9
Red
Overload
If the CU 321 is loaded beyond the current limit and if a reduction of the output frequency
does not reduce the load, the CU 321 will give an alarm 9. The CU 321 is alarm-locked.
12
Yellow
Current limit
The output current is greater than the max. value allowed by the CU 321.

Grundfos CU 321 Specifications

General

Brand	Grundfos
Model	CU 321
Category	Control Unit
Language	English