CIRCUTOR OPTIM Series - Manual (Page 12)

OPTIM SERIES
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5.3.4 Earth cable connection
Connect the earth cable to the capacitor bank's earth terminal located on the equipment operating
panel. The cable size will be selected in accordance with the admissible current limits established
in the REBT (ITC-BT-19 – Internal or receiver installations) for each type of cable and their
location.
5.3.5 Connecting the current transformer (CT)
A current transformer (CT) that is external to the bank must be installed to
measuring the total load current plus the bank (see Fig. 5-3).
The standard transformer has a nominal output of 5 A at the secondary winding.
It is recommended to connect the CT to phase L1 in the direction of the current
flow from P1 to P2 (see Fig. 5-3) and connect the secondary winding (terminals
S1, S2) to the terminals with the same name on the bank (see Fig. 5-3).
Avoid current flow through the CT primary winding prior to connecting it to
terminals S1 S2 of the bank. If the CT must be installed while recharging the
installation, short-circuit S1 and S2 as long as they are not connected to the
bank.
• The current value of the CT primary winding must be equal or somewhat greater than the size
of the installation's mains switch. Therefore, the CT must be able to measure the maximum
current that is foreseen will be consumed by all the loads to be compensated.
Fig. 5-3 .- Installation of the current transformer (CT) (external)
• The connection point of the CT for a bank that compensates an entire installation is after the
installation's mains switch.
• To prevent excessive attenuation of the signal, the minimum secondary winding cable size
(terminals S1, S2) is recommended to be at least 2.5 mm
2
.
Fig. 5-4.- CT and neutral connection terminals if required