VAMP 52 - 3.4. Current transformer supervision

Technical description 3 Supporting functions 3.4 Current transformer supervision
VM50.EN004 VAMP 24h support phone +358 (0)20 753 3264
117
Parameters of the cold load & inrush detection function
Parameter Value Unit Description Note
ColdLd -
Start
Trip
Status of cold load detection:
Cold load situation is active
Timeout
Inrush -
Start
Trip
Status of inrush detection:
Inrush is detected
Timeout
ILmax A
The supervised value. Max. of
IL1, IL2 and IL3
Pickup A Primary scaled pick-up value
Idle A
Primary scaled upper limit for
idle current
MaxTime s Set
Idle xImode
Current limit setting for idle
situation
Set
Pickup xImode
Pick-up setting for minimum
start current
Set
80 ms
Maximum transition time for
start recognition
Pickupf2 %
Pick-up value for relative
amount of 2
nd
harmonic, I
f2
/I
f1
Set
Set = An editable parameter (password needed)
3.4. Current transformer supervision
The relay supervise the external wiring between the relay
terminals and current transformers (CT) and the CT them
selves. Furthermore, this is a safety function as well, since an
open secondary of a CT, causes dangerous voltages.
The CT supervisor function measures phase currents. If one of
the three phase currents drops below I
min
< setting, while
another phase current is exceeding the I
max
> setting, the
function will issue an alarm after the operation delay has
elapsed.
Setting parameters of CT supervisor CTSV ( ):
Parameter Value Unit Default Description
Imax> 0.0 … 10.0 xIn 2.0
Upper setting for CT
supervisor
Imin< 0.0 … 10.0 xIn 0.2
Lower setting for CT
supervisor
t>
0.02 …
600.0
s 0.10 Operation delay
CT on On; Off - On CT supervisor on event
CT off On; Off - On CT supervisor off event