MR8740、MR8741_user_manual_eng_20191016H.pdf - 第23页

Operating Precautions 11 Before Connecting Cables When measuring power line volt age • Connecting cables should only be c onnected to the secondary sid e of a breaker Even if there is a short circuit on the secondary sid…

Operating Precautions

• Before transporting the instrument, disconnect all cables and USB memory

sticks.

• When there is no input, the waveform might be unstable due to the induced

voltage, but this is not an error.

• This instrument may cause interference if used in residential areas. Such use

must be avoided unless the user takes special measures to reduce electro-

magnetic emissions to prevent interference to the reception of radio and televi-

sion broadcasts.

Handling Media

• Do not remove the media while it is being accessed by the instrument. Data on

the media could be lost.

• Do not turn off the power to the instrument while the media is being accessed

by the instrument. Data on the media could be lost.

• Do not transport the instrument while a USB flash drive is connected. Damage

could result.

• If damage occurs to the data on the media, we cannot restore or analyze the lost

data. No compensation will be provided, regardless of the type or cause of the

problem or damage.We therefore recommend maintaining a backup of any

important data.

• Be careful to avoid inserting a media backwards or upside-down. The media or

the instrument could be damaged.

• Never insert or eject a media while it is being accessed by the instrument. Data

on the media could be lost.

• Do not operate the instrument at a slanted angle. It may not work properly.

• Do not transport the instrument while a USB memory stick is connected. Dam-

age could result.

• Some USB memory sticks are susceptible to static electricity. Exercise care

when using such products because static electricity could damage the USB

memory stick or cause malfunction of the instrument.

• With some USB devices, the instrument may not start up if power is turned on

while the device is inserted to the USB port. In such a case, turn power on first,

and then insert the USB device. It is recommended to try out operation with a

USB memory stick before starting to use it for actual measurements.

• Peculiar USB memory requiring fingerprint authentication or password cannot be

used.

• When saving or loading data, insert the storage media before selecting it. If the

media is not inserted, the file list display will not appear.

• All media (USB memory) have a limited service life. After extensive use over a

long period, data retention and readout may become stop working. In that

case, replace the card with a new one.

• Automatic saving of data is possible only on USB memory stick media.

• The data can be automatically stored in the USB flash memory; however, it is

not guaranteed to work.

Operating Precautions

Before Connecting Cables

When measuring power line voltage

• Connecting cables should only be connected to the secondary side of a

breaker Even if there is a short circuit on the secondary side of the breaker, the

breaker cuts off the electric supply. Do not connect to the primary side of a

breaker because unrestricted current flow could damage the instrument and

facilities if a short circuit occurs.

• To prevent electrical shocks and personal injury, do not touch any input termi-

nals on the VT (PT), CT or the instrument when they are in operation.

• Do not permanently connect the instrument in an environment where voltage

surges exceeding the maximum input voltage may occur. Applying voltage

may result in damage to the instrument, or a serious accident.

• Do not short-circuit two wires to be measured by bringing the connection

cables into contact with them. Arcs or such grave accidents are likely to occur.

• To avoid short circuit or electric shock, do not touch the metal parts of the con-

necting cable clips.

• To avoid electrical shocks, be careful to avoid shorting live lines with the con-

nection cable clips.

• To avoid electric shock and short-circuit accidents, use only the specified test

leads to connect the instrument input terminals to the circuit to be tested.

• To prevent an electric shock, confirm that the white or red portion (insulation

layer) inside the cable is not exposed. If a color inside the cable is exposed, do

not use the cable.

• The cable is hardened under the 0°C (32°F) or colder environment. Do not

bend or pull cables in such environments to avoid tearing insulation or break-

ing the cable.

•

Connecting to the BNC jacks on modules

Do not use a metal BNC connector. If you connect a metal BNC cable to an

insulated

BNC connector, the insulated BNC connector can be damaged and the instru-

ment may be damaged.

• To prevent cable damage, do not step on the cable or pinch them between

other objects. Do not bend or pull cables at their base.

• Use only the specified connection cables. Using a non-specified cable may

satisfy the specification requirements due to poor connection or other reasons.

• For detailed precautions and instructions regarding connections, refer to the

instruction manuals for your modules, connection cables, etc.

Operating Precautions

Before Connecting a Logic Probe to the Measurement Object

To avoid electric shock and short circuit accidents or damage to the instru-

ment, pay attention to the following:

• The ground pin in the LOGIC connector (plug) of the Model 9320-01 and

9327 Logic Probes (and legacy Models 9306 and 9320) is not isolated

from this instrument’s ground (common ground).

Use grounding-type polarized power cords for the measurement object

and this instrument, and obtain power from the same mains circuit.

Connecting to different mains circuits or using a non-grounding power

cord may cause damage to the measurement object or this instrument

because of current flow through the logic probes resulting from potential

difference between the grounds of the different wiring systems.

To avoid these problems, we recommend the following connection pro-

cedure:

Measurement

Object

Memory

HiCorder

Logic probe

Connect this instrument to the same

outlet as the measurement object us-

ing the (supplied) grounding polar-

ized power cord.

ground to the GND terminal

(functional earth terminal) of this

instrument.

(Always obtain power from the

same mains circuit.)

Measurement

Object

Logic probe

Functional

Earth Termi-

nals

GND

Memory

HiCorder

Before Turning the Power Supply On

• To avoid electrical accidents and to maintain the safety specifications of this

instrument, connect the power cord provided only to an outlet.ïï

• Before turning the instrument on, make sure the supply voltage matches that

indicated on its power connector. Connection to an improper supply voltage

may damage the instrument and present an electrical hazard.

• Avoid using an uninterruptible power supply (UPS), DC/AC inverter with rect-

angular wave or pseudo-sine-wave output to power the instrument. Doing so

may damage the instrument.

• To avoid damaging the power cord, grasp the plug, not the cord, when unplug-

ging it from the power outlet.

Turn off the power before disconnecting the power cord.