Installation Of Current Transformers - Leviton MDNCT-2SC Manual Del Usuario E Instalación

3 INSTALLATION INSTRUCTIONS
3.8.3

Installation of Current Transformers

General Requirements:
• If CT secondary wires are routed through conduit, splices on the CT leads
must be within the meter enclosure, not inside the conduit. Leviton-provided
CT lead wires are 48 inches long, 18 AWG.
• It is acceptable to route voltage input wires and CT secondary wires through
the same conduit as long as all the wiring in the conduit meets National
Electric Code requirements (at least 18 AWG). CTs should be securely
fastened such that they will not slide down to live terminals.
• Current and voltage inputs must be installed 'in phase' for correct readings.
As shown in Figure 6, CT1 needs to monitor the same phase as the voltage
connected to the meter on L1 and CT2 needs to monitor the same phase
as the voltage connected to the meter on L2. The CTs must be connected
between line and load, not on the voltage wires that lead to the meter.
• Be sure to install the CTs with the correct orientation (direction). If the meter
displays a Reverse Energy error after installation (see Table 7), it is likely that
you have either installed a CT backwards or have reversed the X1 and X2
terminal connections.
1.
2.
3.
4.
5.
Strip wiring to 0.3 inch.
Trim the wire to the appropriate length to avoid coils of excess wiring.
Connect the CT leads to the appropriate terminals; see wiring diagrams
(Figure 6) for correct CT orientations and connections. A list of the CT
connections is given in Table 3.
For Split Core CTs:
a. Remove the thumb screws at the bottom side of the CT as shown in Figure 5
(left) and pull away one side of the CT to open it as shown in Figure 5 (right).
b. With power to the conductors turned off, place the CT around the
appropriate conductor while ensuring that the white labels (the side
facing up in the figure) faces Line (source).
c. Note the white mark on the removed section of the CT and make
sure to align it with the white mark on the CT case. (The white mark
is visible at the lower corner of the CT in Figure 5.) Close the CT by
sliding the removed section back into place and replacing the thumb
screws. For accuracy, it is very important to be sure the white marks
are aligned and the CT is completely closed with the screws installed.
d. Connect the CT wires to the meter inputs as described in Table 3.
e. Repeat for remaining conductor for two phase applications, as shown
in Figure 6.
Figure 5 - Split Core CT, Closed (left) and Open (right)
For Solid Core CTs: With power turned off, disconnect each monitored
conductor one at a time and slide on appropriate CT, ensuring the CT is
correctly oriented as shown in Figure 6. Reconnect the conductors. Connect
the CT wires to the meter inputs as described in Table 3.
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