Yokogawa EJA530A - Manual (Page 10)

IM 01C21F01-01E 2-2
2. HANDLING CAUTIONS
(c) Shock and Vibration
Select an installation site suffering minimum shock
and vibration (although the transmitter is designed
to be relatively resistant to shock and vibration).
(d) Installation of Explosion-protected Transmitters
Explosion-protected transmitters can be installed in
hazardous areas according to the types of gases for
which they are certified. See Subsection 2.9
“Installation of Explosion Protected Type Transmit-
ters.”
2.5 Pressure Connection
WARNING
• Instrument installed in the process is under
pressure. Never loosen the process connection
part to avoid the dangerous spouting of process
fluid.
• During draining condensate from the capsule
assembly, take appropriate care to avoid
contact with the skin, eyes or body, or inhala-
tion of vapors, if the accumulated process fluid
may be toxic or otherwise harmful.
The following precautions must be observed in order to
safely operate the transmitter under pressure.
(a) Make sure that the process connection part is
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 Waterproofing of Cable
Conduit Connections
Apply a non-hardening sealant to the threads to
waterproof the transmitter cable conduit connections.
(See Figure 6.4.2a, 6.4.2b and 6.4.2c.)
2.7 Restrictions on Use of Radio
Transceiver
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 for such
effects, bring the transceiver in use slowly from a
distance of several meters from the transmitter,
and observe the measurement loop for noise
effects. Thereafter, always use the transceiver
outside the area affected by noise.
2.8 Insulation Resistance and
Dielectric Strength Test
Since the transmitter has undergone insulation resis-
tance and dielectric strength tests at the factory before
shipment, normally these tests are not required.
However, if required, observe the following precau-
tions in the test procedures.
(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 transmitter terminals. Perform the
tests in the following procedure:
• 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 short as possible to verify that the insula-
tion resistance is at least 20 M
Ω.
4) After completing the test and being very careful not
to touch exposed conductors disconnect the
insulation tester and connect a 100 k
Ω 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.