Yokogawa FVX110 - Manual (Page 12)

<2. Handling Cautions>
2-2
IM 01S01C01-01EN
(c) Shock and Vibration
Although the indicator is designed to be
relatively resistant to shock and vibration, an
installation site should be selected where this is
kept to a minimum.
(d) Installation of Explosion-protected Indicators
An explosion-protected indicators is certified
for installation in a hazardous area containing
specific gas types. See subsection 2.8
“Installation of an Explosion-Protected
Indicators.”
2.5 Waterproofing of Cable
Conduit Connections
Apply a non-hardening sealant to the threads to
waterproof the indicator cable conduit connections.
(See figure 5.2, 5.3 and 5.4.)
2.6 Restrictions on Use of Radio
Transceivers
IMPORTANT
Although the indicator has been designed to
resist high frequency electrical noise, if a radio
transceiver is used near the indicator or its
external wiring, the indicator may be affected by
high frequency noise pickup. To test this, start
out from a distance of several meters and slowly
approach the indicator with the transceiver
while observing the measurement loop for noise
effects. Thereafter use the transceiver outside
the range where the noise effects were first
observed.
2.7 Insulation Resistance and
Dielectric Strength Test
Since the indicator has undergone insulation
resistance and dielectric strength tests at the factory
before shipment, normally these tests are not
required. If the need arises to conduct these tests,
heed the following:
(a) Do not perform such tests more frequently than
is absolutely necessary. Even test voltages that
do not cause visible damage to the insulation
may degrade the insulation and reduce safety
margins.
(b) Never apply a voltage exceeding 500 V DC
(100 V DC with an internal lightning protector)
for the insulation resistance test, nor a voltage
exceeding 500 V AC (100 V AC with an internal
lightning protector) for the dielectric strength
test.
(c) Before conducting these tests, disconnect all
signal lines from the indicator terminals. The
procedure for conducting these tests is as
follows:
• Insulation Resistance Test
1) Short-circuit the + and – SUPPLY terminals in
the terminal box.
2) Turn OFF the insulation tester. Then connect
the insulation tester plus (+) lead wire to the
shorted SUPPLY terminals and the minus (–)
leadwire to the grounding terminal.
3) Turn ON the insulation tester power and
measure the insulation resistance. The voltage
should be applied as briefly as possible to verify
that the insulation resistance is at least 20 MΩ.
4) After completing the test and being very careful
not to touch exposed conductors disconnect the
insulation tester and connect a 100 kΩ resistor
between the grounding terminal and the short-
circuiting SUPPLY terminals. Leave this resistor
connected at least one second to discharge any
static potential. Do not touch the terminals while
it is discharging.
• Dielectric Strength Test
1) Short-circuit the + and – SUPPLY terminals in
the terminal box.
2) Turn OFF the dielectric strength tester. Then
connect the tester between the shorted
SUPPLY terminals and the grounding terminal.
Be sure to connect the grounding lead of the
dielectric strength tester to the ground terminal.
3) Set the current limit on the dielectric strength
tester to 10 mA, then turn ON the power and
gradually increase the test voltage from ‘0’ to
the specified voltage.
4) When the specified voltage is reached, hold it
for one minute.
5) After completing this test, slowly decrease the
voltage to avoid any voltage surges.