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2.
Installation and wiring
2.4 Fitting the CTs to the measuring wires
When monitoring one circuit with 1-phase 2-wire, you need one CT. When monitoring one circuit with 1-phase 3-wire,
you need 2 CTs. When monitoring one circuit with 3-phase 4-wire, you need 3 CTs. The following diagram is an
example of fitting CTs when monitoring one circuit with 1-phase 2-wire.
• For details about how to connect the CTs to the measuring wires, refer to the manual of the CTs you are using.
• Fit the CTs to the measuring wires after connecting the CT cables to the unit.
• Attach to the L-phase if measuring 1-phase 2-wire.
Attach to the R-phase and T-phase if measuring 1-phase 3-wire or 3-phase 3-wire.
Attach to the R-phase, S-phase, and T-phase if measuring 3-phase 4-wire.
• Refer to "2.7 Wiring diagrams (
38)" for more on attaching CTs according to the phase and wire types.
• CTs have polarity. Check the directionality of the power side (K) and the load side (L) before connecting. You will
be unable to measure correctly if you make a mistake with the directions.
Important
• Electric shock may occasionally occur.
Always make sure that the power is turned OFF before connecting the CT.
• Make sure that the primary electrical wire clamped at the CT is insulated coated wire.
• Do not expose the CTs to excessive vibrations or impacts.
CT
Power side
Load side
Load
Breaker
L
N
K
L