Hioki PW3335 - Connecting the Measurement Lines

2.2 Connecting the Measurement Lines
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Please read "Handling the Cables" (p.7) carefully before installing, connecting the
measurement lines, or connecting the instrument.
If the measurement target’s voltage and current levels exceed the instrument’s mea-
surement range
By setting the VT ratio and CT ratio, you can read the measured current value (CT primary-side current)
directly.
See: "3.2.8 Setting the VT Ratio and CT Ratio"(p.58)
Wire materials (Voltage input terminal, Current input terminal)
2.2 Connecting the Measurement Lines
Verify that power to the measurement lines has been cut off before connecting the
instrument to them.
To ensure accurate measurement
• When measuring power, the polarity of the voltage and current affects readings, so it is essential to con-
nect the instrument to the measurement lines properly. Accurate measurement will not be possible if these
connections are not made properly.
• Route connected cables away from the instrument so that the electromagnetic field emitted by the cables
does not affect the instrument’s performance.
To prevent electrical shock and personnel injury, do not touch any input terminals on
the VT (PT), CT or the instrument when they are in operation.
• When using an external VT (PT): Do not short the secondary side.
Applying a voltage to the primary side while the secondary side is shorted will cause
a large current to flow to the secondary side, causing it to burn up and resulting in a
fire.
• When using an external CT: Do not leave the secondary side open.
Allowing a current to flow to the primary side while the secondary side is open will
cause a high voltage to occur on the secondary side, which is extremely dangerous.
When using a VT (PT) or CT
• Phase differences between an external VT (PT) and CT can introduce a large error component into power
measurements.
To ensure accurate power measurement, use a VT (PT) and CT with a small phase error in the frequency
band of the circuit being used.
• To ensure safe operation, always ground the load side of the VT (PT) and CT (see figure below)
To avoid electric shock or a short-circuit at the input terminals, use solderless termi-
nals that cover wiring with insulation.
(Screws for voltage input terminals and current input terminals: M6)
To avoid electric shock, use wiring with adequate dielectric strength and current capacity.