MR8740T_Quick guide_eng_20191016H.pdf - 第22页

16 Operation Precautions Before connecting cords For detailed precautions and instructions on connections, refer to the instruction manuals of your connection cords. DANGER • If the insulation on a connecting cable melts…

Operation Precautions

Built-in battery

The instrument contains a battery (sealed lead acid battery) to shut down Windows

in case power

is cut (power outrage or turning off a breaker). Since the battery has a limited life expectancy,

it must regularly be replaced. When replacing batteries, please contact your authorized Hioki

distributor or reseller.

Expected lifetime: About 2 years (Operated at an ambient temperature of

25°, when the instrument is turned off once a day)

About 4 years (Operated at an ambient temperature of

25°, when the instrument is turned off ve times a year)

CAUTION

• You have to charge the battery periodically even if you do not use the instrument.

Periodically charge the battery every three months at a storage temperature of 35°C;

every six months at a storage temperature of 25°C. Failure to do so may reduce the

battery life expectancy.

• Do not install the instrument in a sealed space or near a re. Doing so may cause an

explosion or re.

• Do not use the instrument at high ambient temperature. Do not use the instrument

with the end-of-life battery. Doing so may cause electrolyte leakage, resulting in a bad

inuence that includes a re at a worst. Make sure that you use the instrument within

the operating temperature range and inspect and replace the battery periodically.

Operation Precautions

Before connecting cords

For detailed precautions and instructions on connections, refer to the instruction manuals of your

connection cords.

DANGER

• If the insulation on a connecting cable melts, the metal conductor may be

exposed. Do not use any cable whose metal conductor is exposed. Doing so

could result in an electric shock, burn, or other hazards.

When measuring power line voltage

• Only connect connection cords on the secondary side of a distribution panel. If

a short-circuit occurs on the secondary side of the distribution panel, the panel

will interrupt the short-circuit current. Do not connect the connection cords on

the primary side of the distribution panel because an unrestricted current ow

can damage the connection cords and facilities if a short-circuit occurs.

• To prevent an electrical shock and bodily injury, do not touch any input

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

• Do not leave the measurement cables connected to the instrument in an

environment where voltage may surge beyond the maximum input voltage.

Applying voltage may result in damage to the instrument, or serious accidents.

• Do not cause a short-circuit between another wire and the wire to be measured

with the metal tip of the connection cord. Arcs or such grave accidents are

likely to occur.

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

connection cord.

WARNING

• To prevent an electric shock, conrm 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.

• Do not place a cable in contact with the lines to be measured. Any contact

can cause the instrument to malfunction and lead to a short-circuit or electric

shock, resulting in bodily injury.

• Be sure to connect the voltage input and current input terminals correctly. An

incorrect connection could damage or a short-circuit.

• Use only the specied connection cords. Using a non-specied cable may

result in unsafe measurements. Using a non-specied cable may also result in

incorrect measurements due to poor connection or other reasons.

• To avoid electric shock, do not exceed the lower of the ratings shown on the

modules and connection cords.

Operation Precautions

CAUTION

• To prevent cord damage, do not step on cords or pinch them between other objects.

Do not bend or pull on cords at their base.

• The cable is hardened in freezing temperatures. Do not bend or pull it to avoid tearing

its shield or cutting the cable.

• Do not use any cable terminated with a metal BNC connector for connecting cables

to the BNC jacks on modules. If you connect a metal BNC cable to insulated BNC

connector, the insulated BNC connector and instrument may be damaged.

• To prevent damage to the BNC connector, be sure to release the

locking mechanism, grip the head of the connector (not the cord),

and pull it out.

Before connecting a logic probe to a measuring object

DANGER

To avoid an electric shock, a short-circuit and damage to the instrument, supply

power from a single main to the instrument and a measuring object with the

accompanying power cord.

The ground pin of logic terminal of Model 9320-01 Logic Probe (or Model 9327

Logic Probe) is not isolated from the instrument ground. The ground is shared.

If each of the terminals are supplied with power from separate mains or power

is supplied through a non-grounded power cord, the measuring object and the

instrument may be damaged because a current may ow through the logic probe

due to the resulting ground potential difference between the terminals. The

following connection procedure is recommended to avoid this problem:

• Connect the power cord provided

to the instrument and supply

power from the same outlet as the

measuring object.

• Connect the ground of the

measuring object to the GND

terminal (functional earth terminal)

of the instrument.

(Always supply power from a single

main.)

Refer to “2.6 Supplying Power to

the Instrument” (p. 60).

Functional ground terminal

GND

Logic

probe

Model MR8740T

Measuring

object

Measuring

object

Logic

Probe