Hioki PW3336-01, Instruction Manual

Page: 109 / 206

3.9 Using a Current Sensor
103
Before connecting a current sensor
Please read Operating Precautions (p.5) carefully before connecting a current sensor to the instru-
ment.
When the clamp sensor is opened, do not short-circuit two wires to be measured by
bringing the metal part of the clamp into contact with them, and do not use over bare
conductors.
• Do not connect or disconnect connection cords from the current sensor or 9555-10 Sensor
Unit while the instrument is turned on. Doing so may damage the instrument, current sen-
sor, or 9555-10 Sensor Unit.
• Do not input current to the current sensor when it is not connected to the instrument or
when the instrument and 9555-10 Sensor Unit are turned off. Doing so may damage the
current sensor, instrument, or 9555-10 Sensor Unit.
• When connecting a current sensor to the instrument or 9555-10, disconnect the current
sensor from the target measurement line and verify that no current is being input.
• When disconnecting the current sensor or 9555-10 from the instrument, be sure to do so
by gripping the BNC connector and pulling after disengaging the lock. Pulling on the con-
nector without disengaging the lock or pulling on the cord may damage the connector.
• Avoid stepping on or pinching cables, which could damage the cable insulation.
• When using the 9555-10, use the L9217 Connection Cord (which is made of plastic). Using
a metal BNC cable may damage the instrument’s external current sensor input terminals
(which are made of plastic) or the instrument.
• Be careful to avoid dropping the current sensors or otherwise subjecting them to mechani-
cal shock, which could damage the mating surfaces of the core and adversely affect mea-
surement.
• Do not place the current sensor’s core tips around foreign objects or insert foreign objects
into the core slits. Doing so may degrade current sensor performance or prevent it from
opening and closing properly.
• When not using a current sensor, place the clamp in the closed position. Storing the sensor
with the clamp in the open position may allow dirt or dust to accumulate on the mating core
surfaces, which could interfere with clamping action.
• When using external current sensor input, disconnect any lines from the current direct
input terminals. When using the current direct input terminals, disconnect any lines from
the external current sensor inputs.
• When using a wiring mode other than 1P2W, the current sensor type, CT ratio, and range will be standard-
ized using the CH1 settings.
• The instrument’s settings can be used to switch between current direct input terminals (maximum input
current of 70 A, ±100 Apeak) and external current sensor input terminals. Current signals input to input
terminals that are not set as enabled are ignored.
• The instrument’s CT ratio is set based on the current sensor type and rating. If the CT ratio is set improp-
erly, it will be impossible to conduct accurate measurement.
• The measurement accuracy when using a current sensor is obtained by adding the instrument’s external
current sensor input measurement accuracy and the current sensor’s measurement accuracy.
• Depending on the current sensor being used, the instrument’s accuracy defined range may be narrower
than the current sensor’s frequency band.