5
—
0
—
04
After connection of the terminal, the terminal box
is closed by a cover and bushing plate with corre-
sponding sealing compound against penetration
of splash water.
The number of terminal boxes may be changed af-
ter agreement between the customer and manu-
facturer and according to the type of transformer.
Max. number of terminal boxes is shown in the ta-
ble below.
Type
Max.Number of
terminal boxes
Position
ELK CN3 - 1080mm
6
1, 2, 3, 4,5,6
ELK CN3 - 720mm
2
1, 2
ELK CN14 - 840mm
4
1, 2, 3, 4
ELK CN14 - 560mm
2
1, 2
CN14C
1
1
—
05
Mounting
The transformers ELK - CN are designed as
low-voltage current transformers 0.72/3kV, with-
out a built in primary conductor. For use in higher
voltages it is therefore necessary to combine
them with the primary conductor with self-isola-
tion. A primary conductor is not included in the
supply.
Mounting and placement of the ELK - CN trans-
formers is proposed by the customer depending
on application and using of the primary conduc-
tor and its insulation. The transformer has a
flange with holes used to attach the transformer
screws. Before installation of the primary conduc-
tor and whole transformer, clean the sealing sur-
face and inside surface of the transformer from
dust, grease and another impurities, see 5. Main-
tenance instructions. For each type of ELK - CN
transformer use the corresponding fasteners, pri-
mary conductor and insulator. Use only a primary
conductor designed by ABB.
4. Instructions for use
Current instrument transformers are used:
• to convert currents in the primary circuit to an
appropriate level for secondary circuit equip-
ment (relays and meters)
• to insulate the primary and secondary circuit
from each other to protect the secondary
equipment from the harmful effects of current
appearing during the operation (short circuits)
The use of a current transformer for a purpose
other than described above is forbidden if not
agreed with the producer.
Routine test report
The routine test report of a current instrument
transformer includes:
a) verification of terminal markings
b) inter-turn overvoltage test
c) determination of errors
d) power-frequency test
Upon the customer’s request the following infor-
mation can be provided free of charge:
• theoretical current/voltage error and phase dis-
placement values
• theoretical excitation (magnetization) curves
—
04 Mounting of terminal
box
—
05 Example of
transformer ELK CN3
– 1080 mm with six
terminal boxes
