26 36KV I
S
LIMITER PANEL INSTALLATION, OPERATION AND MAINTENANCE MANUAL
6.4 Electrical displays and
monitoring
When the switchgear is in operation, all the
visible operating data and condition indicators in
the secondary systems are to be observed.
Indicator for power supply:
"No power supply" indication (indicator relay
visible at the back of the door of the tripping
cabinet).
Indicators for I
S
-limiter
TM
:
Indicator relay visible at the back of the door of
the tripping cabinet (see also section 3.5.4).
• "I
S
-limiter
TM
not ready" indication
(indicator relay)
• "I
S
-limiter
TM
tripped" indication
(3 indicator relays)
6.5 Earthing and short
circuiting with earthing
cable set
Earthing and short-circuiting of the installation
with an earthing cable set can be effected if the
system is so ordered.
Application on switchgear fitted with phase
earthing points, which can be mounted on both
the cable and/or busbar sides.
Note
The short-circuit withstand capacity of the
earthing device must correspond to the rated
short time current of the switchgear.
The individual steps of the earthing and
short- circuiting process are as follows:
• Isolate the area to be earthed and secure
against reconnection
• Carefully observe all safety regulations
- Check the area to be earthed for the
off-circuit condition, e.g. with a voltage
tester in the measuring point sockets of
the capacitive voltage indicator system
(if fitted), or with a high-voltage tester at
the relevant earthing points
- First firmly bolt the common earthing
cable to the earthing point, and then use
the insulated rod to connect the
short-circuiting cable in a short-circuit-
proof manner to the phase earthing points
- Secure neighbouring live areas (e.g. feeder
cables) to prevent inadvertent contact
6.6 Test procedures
6.6.1 Testing the off-circuit condition
In switchgears which are not equipped with
capacitive voltage indication checking the
off-circuit condition is carried out with a HV
tester on the lower side T Connection of
the I
S
-limiter
TM
.
If the switchgears are equipped with capacitive
voltage indication, checking the off-circuit
condition can be carried out by means of this
device. In this case, proceed according to the
manufacturer’s instructions for the indicators. In
case of any doubt about correct operation of
capacitive voltage indication, the off-circuit
condition must be checked using a HV tester.
CAUTION!
Checking the off-circuit condition
must always be carried out in
compliance with the relevant safety
regulations and local operating
conditions
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