4
CU R R E NT TR A N S FOR M E R S FOR G A S - I N SU L ATE D SWITCHG E A R T YPE E LK
—
0
—
02
The connection schema nameplate is placed un-
der the cover of the terminal box.
3. Instruction for installation
General information
The instrument transformer is electrical equip-
ment and the electrical installation of the instru-
ment transformer can be done by skilled person-
nel, only. The level of experience, age and
eligibility criteria for persons working with, on or
near electric installations is governed by national
legislation. If no such eligibility legislation is avail-
able the corresponding requirements can be
found in the EN 50110-1 standard.
Safety instructions
1. Always consider the transformer as a part of
electric circuit which it is connected to. Don’t
touch incoming connectors and terminals, or
any other parts of the transformer, unless you
know for sure these are earthed.
2. Always ground the metallic base of the instru-
ment transformer.
3. Always connect one terminal of each secondary
winding of the transformer to the earth. When
the secondary of the transformer is intercon-
nected, there should be only one grounded
point to prevent accidental paralleling with the
system grounding wire.
4. Always short-circuit the secondary of a current
transformer that is not currently in use, to pre-
vent secondary voltages, which may be hazard-
ous to personnel or damaging to the trans-
former’s secondary. The secondary, like this,
must be additionally grounded.
Connection of transformer primary side
The ELK - CN transformers don’t have their own
primary conductor. If ELK - CN transformers will
be used in other applications than ABB switchgear
ELK-3, ELK-14 or ELK-14/245C please contact us
for support.
Attention:
a primary conductor must be centred
in the application with tolerance ±1cm.
Connection of transformer secondary side
For all current transformers, the secondary cable
connections must be led to a terminal box. The
transformers ELK - CN contain an outlet cable
which is connected to the terminal on the DIN rail.
If not specified otherwise in the order, the cable
cross-section may not exceed 6mm2.The termi-
nals are equipped with M4 screws for connection
of the secondary outlets. Maximum allowed
torques for secondary screw connections:
Highest and lowest allowed torque values
for secondary screw connections
Screw
Highest torque (Nm)
Lowest torque (Nm)
M4
1.8
1.5
The end of the windings of all cores are corre-
spondingly identified. Terminal arrangement ac-
cording to the number of terminals and parame-
ters of transformer. The type of terminals and
terminal arrangement may be changed by the
customer after agreement with the manufacturer.
—
03
—
02 Example of current
transformer connection
schema nameplate
—
03 Example of a sec-
ondary terminal board
of the ELK - CN type
transformers
