Hioki RM3545, Instruction Manual, Page: 24 / 364

Operating Precautions
16
Before Measuring
•
To avoid electric shock or damage to the
instrument, do not apply voltage to the
measurement terminals. Also, to avoid
electrical accidents, only take measure-
ments after turning off the power to the
measurement targets being measured.
•
Sparks may result at the moment the instrument is connected to, or
disconnected from, the measurement target. To avoid fire or bodily
injury, avoid use in the presence of explosive gases.
The measurement target is
connected to a power supply.
•
Battery internal resistance cannot be measured with this instrument. It will
sustain damage. To measure battery internal resistance, we recommend the
HIOKI 3554, 3555, BT3562, BT3563 and 3561 Battery HiTesters.
•
Never attempt to measure at a point where volt-
age is present. Even if the power supply to the
motor is turned off, while the motor is rotating
inertially, high electromotive power is generated
in terminals. When attempting to measure a
transformer or motor immediately after voltage
withstanding test, induced voltage or residual
charge may damage the instrument.
Rotating inertially
•
When the RM3545 is used in a way that connects to a withstanding voltage
tester via switching relays, construct a testing line bearing the following in
mind.
See: "Appendix 15 Using the Instrument with a Withstanding Voltage Tester" (p. A33)
(1) The voltage withstanding specification of switching relays should
include a safe margin over the withstanding testing voltage.
(2) To protect against damage due to arc discharge in relay contacts, all
RM3545 measurement terminals should be grounded during voltage
withstanding testing.
(3) To protect against damage due to residual charge, measure resistance
first, and voltage withstanding last.
3158 AC Withstanding Voltage HiTester RM3545
Withstand voltage of relay switch is not high enough.
Residual charge from voltage
withstanding test is present.