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4 selecting the installation location, 5 pressure connection, 6 waterproofing of cable conduit connections – Yokogawa EJX930A User Manual

Page 19: 7 restrictions on use of radio transceivers, Selecting the installation location -2, Pressure connection -2, Waterproofing of cable conduit connections -2, Restrictions on use of radio transceivers -2, 5 pressure connection warning

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<3. Handling Cautions>

3-2

IM 01C25R01-01E

(b) When storing the transmitter, repack it carefully

in the packaging that it was originally shipped

with.

(c) If the transmitter has been used, thoroughly

clean the chambers inside the cover flanges, so

that there is no process fluid remaining inside.

Before placing it in storage, also make sure that

the pressure-detector is securely connected to

the transmitter section.

3.4 Selecting the Installation

Location

The transmitter is designed to withstand severe

environmental conditions. However, to ensure

that it will provide years of stable and accurate

performance, take the following precautions when

selecting the installation location.
(a) Ambient Temperature

Avoid locations subject to wide temperature

variations or a significant temperature gradient.

If the location is exposed to radiant heat from

plant equipment, provide adequate thermal

insulation and/or ventilation.

(b) Ambient Atmosphere

Do not install the transmitter in a corrosive

atmosphere. If this cannot be avoided, there

must be adequate ventilation as well as

measures to prevent the leaking of rain water

and the presence of standing water in the

conduits.

(c) Shock and Vibration

Although the transmitter 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 Transmitters

An explosion-protected transmitters is

certified for installation in a hazardous area

containing specific gas types. See subsection

3.9 “Installation of an Explosion-Protected

Transmitters.”

3.5 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.

3.6 Waterproofing of Cable

Conduit Connections

Apply a non-hardening sealant to the threads

to waterproof the transmitter cable conduit

connections. (See figure 7.8, 7.9 and 7.10)

3.7 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.

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