Quadlogic MiniCloset-5c, Руководство по установке, Страница: 20 / 117

Chapter 4 Installation
© COPYRIGHT 2009
Quadlogic Controls Corporation
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DANGER:
Un-terminated CT secondary wires will produce hazardous electrical potentials if any current
is flowing through the CT. While connecting the CTs, POWER MUST BE OFF until the CTs
have all been connected to the MCI. Before power can be turned on, either the shorting
links must be in place, or the 4 CT connectors must be plugged in to the meter head.
Turning the power on with the meter unplugged and the shorting links removed will result in
a condition that is hazardous to equipment and personnel.
This is the general procedure for connecting the current transformers. For specific wiring
instructions, refer to page 18 to identify the current instructions for your meter model.
1. Make sure shorting links are installed on the MCI.
2. Each CT is supplied with two secondary wires. One of these wires is colored either black,
red, or blue, and the other wire is white. These 2 wires must pass through the conduit
to the MC-5c back box, and connect to screw terminals on the MCI.
3. If the wires that are supplied with the CTs are too short to reach the MCI screw
terminals, they may be extended to different length depending upon the gauge of the
wire as shown in the table 4-2. (For the file runs over 50’ use a shielded twisted pair.)
The wire extensions should be black, red, or blue wire to match the existing CT wire.
Extend the white wire of each CT with a white wire. It is very important to maintain the
association of particular CT’s secondary wires. You must keep track of which white wire
goes with each individual colored wire. It may be helpful to tape them together before
being pulling them through the conduit.
Length (feet) Wire Size (AWG)
0.1A CT 5A CT
#16 223 21
#14 355 34
#12 562 53
#10 893 85
Table 4-2: CT wire extension length
Wire color coding may vary depending on local codes and regulatory standards within certain
jurisdictions.
Refer to the Phase Association tables later in this chapter when wiring the MCI. Failure to
observe proper phase association will result in incorrect metering data.
4. Locate the branch load hot wires that supply current from the distribution panel to the
metered loads. Disconnect these wires one (or two) at a time and properly run each wire
(or pair of wires) through a CT. The colors of the CT leads must correspond to the color
of the tape on the phase feeder wires that supply this load. The correct way to run the
load wires through the CT is different for different installations.
5. Run the CT secondary wires through the conduit to the MC-5c back box. Connect each
CT to its proper pair of screw terminals. It is very important the 2 wires from a
particular CT go to the corresponding pair of screw terminals on the MCI. For example, if
the black wire from a CT goes to terminal “I1”, then the white wire from that same CT