L3447
Emax DC
47/108
Model
Scale
Page No.
Doc. No.
Apparatus
1SDH000635R0002
L3728
12.7 Troubleshooting PR122/DC unit
The following table lists a series of typical service conditions, to help you understand and solve hypothetical faults or malfunctions.
Note:
1.
Before consulting the following table, check for any error messages appearing for some seconds on the display.
2.
FN indicates the normal operation of the PR122/DC.
3.
In the case where the suggestions proposed do not lead to a solution of the problem, please contact the ABB SACE assistance service.
N o .
Situation
Possible causes
Suggestions
1
The trip test cannot be run
1. The busbar current is > 0.
1. FN
2. The TC is not connected
2. Check the messages on the display
3. CB open
2
Trip times lower than expected
1. Threshold too low
1. Correct threshold
2. Curve too low
2. Correct curve
3. Thermal memory enabled
3. Exclude if not necessary
4. The SdZ is inserted
4. Exclude if not necessary
3
Trip times higher than expected
1. Threshold too high
1. Correct threshold
2. Curve too high
2. Correct curve
3. Curve I
2
t inserted
3. Exclude if not necessary
4 Rapid trip, with I3=Off
Iinst tripped
FN with short-circuit with high I
5
Display off
1. Faulty voltage sockets connection
1. Warning, see 12.3.4
2. Vaux missing and the
2. FN, see 12.2.2.1
voltage is below the minimum value.
3. Temperature out of range
3. FN, see 12.2.9.5
6
The display is not back-lit
Volatge below the
FN
limit for lighting the display
7
Reading of I incorrect
Current below the minimum threshold FN
that can be displayed
8
" Local Bus" message
No communication between
1. If not present, disable PR021/K,
on display
PR122/DC and PR021/K
see 12.5.4.2.3
2. Check bus connection
3. Check PR021/K
9
Message ""
Function disabled or data
FN
instead of expected data
out of range
10
The expected trip does not occur
Trip function disabled
FN enable trip if necessary
11
No display
Vaux missing, the buffer
FN, see 12.5.6.1
of the opening data
capacitor is discharged
12
The password is not requested
The password has been disabled
FN, re-enter the password with a value
other than 0000.
13
Impossible to change any
PR122/DC in alarm situation
FN
parameter
14
" Temp. sensor" or
Possible failure inside relay
Contact ABB Sace
" Start-up" message
15
Invalid date
1.First installation
FN see 12.4.3.1
2. Information lost due to power
failure
16
Untimely trip
See 12.6.3
17
Led lighting
See 12.6.1
18
The language cannot be changed
1. The relay is remotely set
1. Local setting
2. CB not open
2. Open CB
12.7.1 In the case of a fault
If you suspect that the PR122/DC is faulty, has a malfunction or has generated an unwanted trip, it is advisable to follow the
recommendations below very carefully from the Measurements menu Historicals Trip:
1. Make a note of the type of protection that has tripped by accessing the LAST TRIP page if there is an external power supply (Vaux or battery)
or by pressing "i Test" if in self-supply mode.
2. Note down the type of circuit-breaker, number of poles, any accessories connected, In, Serial Number (see par. 12.4) and the SW version.
3. Prepare a brief description of the opening (what LEDs and/or indications were displayed? when did it happen?, how many times ?, was it always
under the same conditions? what type of load? what voltage? what current? is the event reproducible?)
4. Send/communicate all the information collected, together with the circuit diagram for the circuit-breaker, to your nearest ABB Customer Support
service.
The completeness and accuracy of the information given to the ABB Assistance service will facilitate technical analysis of the problem encountered,
and will allow us to carry out all actions useful for the user rapidly.
