Yokogawa EJX530B - Manual (Page 11)

<2. Handling Cautions>
2-3
IM 01C27F01-01EN
2.5 Pressure Connection
WARNING
• Never loosen the process connector bolts
when an instrument is installed in a process.
The device is under pressure, and a loss of
seal can result in a sudden and uncontrolled
release of process fluid.
• When draining toxic process fluids that have
condensed inside the pressure detector,
take appropriate steps to prevent the contact
of such fluids with the skin or eyes and the
inhalation of vapors from these fluids.
The following precautions must be observed
in order to safely operate the transmitter under
pressure.
(a) Make sure that all the process connector bolts
are tightened firmly.
(b) Make sure that there are no leaks in the impulse
piping.
(c) Never apply a pressure higher than the
specified maximum working pressure.
2.6 Restrictions on Use of Radio
Transceivers
IMPORTANT
Although the transmitter has been designed to
resist high frequency electrical noise, if a radio
transceiver is used near the transmitter or its
external wiring, the transmitter may be affected
by high frequency noise pickup. To test this, start
out from a distance of several meters and slowly
approach the transmitter 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 transmitter 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) The procedure for conducting these tests is as
follows:
• Insulation Resistance Test
1) Remove the battery pack. See subsection 9.4.5
for details on how to remove it.
2) Short-circuit the battery connection terminals in
the terminal box.
3) Turn OFF the insulation tester. Then connect
the insulation tester plus (+) lead wire to the
shorted battery connection terminals and the
minus (–) leadwire to the grounding terminal.
4) 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.
5) 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 battery connection terminals. Leave
this resistor connected at least one second to
discharge any static potential. Do not touch the
terminals while it is discharging.