L2234
Emax
74/158
Model
Scale
Page No.
Doc. No.
Apparatus
1SDH000460R0002
L2778
13.7 Troubleshooting PR122/P 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/P.
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. Incorrect Neutral Selection
4. Correct neutral selection
5. The SdZ is inserted
5. 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. Incorrect Neutral Selection
4. Correct neutral selection
4
Rapid trip, with I3=Off
Iinst tripped
FN with short-circuit with high I
5
High earth I, but no trip happens
1. Incorrect selection of the sensor
1. Set int. or ext. sensor
2. Function G prevented with I>4In
2. FN
6
Display off
1. Vaux missing and the current and/or 1. FN, see 13.2.2.1
voltages are below the minimum value.
2. Temperature out of range
2. FN, see 13.2.9.8
7
The display is not back-lit
Current and/or volatges below the
FN
limit for lighting the display
8
Reading of I incorrect
Current below the minimum threshold FN
that can be displayed
9
Reading of V, W and power factor
1) Connection error between VT and 1) Check connections between VT and
incorrect
PR120/V
PR120/V
2) VT parameter settings error
2) Set the correct parameters
10
" Local Bus" message
No communication between PR122/P 1. If not present, disable PR021/K,
on display
and PR021/K
see 13.5.4.4.5
2. Check bus connection
3. Check PR021/K
11
Message ""
Function disabled or data
FN
instead of expected data
out of range
12
The expected trip does not occur
Trip function disabled
FN enable trip if necessary
13
No activation of the Unbalance
Values of I out of range
FN, see 13.2.9.5
U protection
14
No display
Vaux missing, the buffer
FN, see 13.5.6.1
of the opening data
capacitor is discharged
15
The password is not requested
The password has been disabled
FN, re-enter the password with a value
other than 0000.
16
Impossible to change any
PR122/P in alarm situation
FN
parameter
17
" Temp. sensor" or
Possible failure inside relay
Contact ABB Sace
" Start-up" message
18
Invalid date
1.First installation
FN see 13.4.3.1
2. Information lost due to power
failure
19
Untimely trip
See 13.6.3
20
Led lighting
See 13.6.1
21
The language cannot be changed
1. The relay is remotely set
1. Local setting
2. CB not open
2. Open CB
3. Vaux or PR120/V or PR030/V
3. Power the relay
not installed