<INSTALLATION AND OPERATING PRECAUTIONS FOR FLAMEPROOF ENCLOSURE
“d” CERTIFIED UNDER JAPANESE TYPE CERTIFICATION>
3
EX-B05-1EN
6. Maintenance of Flameproof Equipment
To maintain the flameproof equipment, do the
following. For details, read USER’S GUIDELINES
for Installations for Explosive Atmospheres in
General Industry.
(1) Maintenance servicing with the power on.
Flameproof equipment shall not be
maintenance-serviced with its power turned
on. However, in cases where maintenance
servicing is to be conducted with the power
turned on, with the equipment cover removed,
always shall use a gas detector to check that
there is no explosive gas in that location. If it
cannot be checked whether an explosive gas is
present or not, maintenance servicing shall be
limited to the following two items:
(a) Visual inspection
Visually inspect the flameproof equipment,
metal conduits, and cables for damage
or corrosion, and other mechanical and
structural defects.
(b) Zero and span adjustments
These adjustments should be made only to
the extent that they can be conducted from
the outside without opening the equipment
cover. (e.g. by software) In doing this,
great care must be taken not to cause
mechanical sparks with tools.
(2) Repair
If the flameproof equipment requires repair,
turn off the power and transport it to a safety
(non-hazardous) location. Observe the
following points before attempting to repair the
equipment.
(a) Make only such electrical and mechanical
repairs as will restore the equipment to
its original condition. For the flameproof
equipment, the gaps and path lengths of
joints and mating surfaces, and mechanical
strength of enclosures are critical factors
in explosion protection. Exercise great
care not to damage the joints or shock the
enclosure.
(b) If any damage occurs in threads, joints
or mating surfaces, inspection windows,
connections between the sensor and
terminal box or clamps, or external
wiring connections which are essential
in flameproof, contact Yokogawa Electric
Corporation.
CAUTION
Do not attempt to re-process threaded
connections or refinish joints or mating surfaces.
(c) If you attempt to repair the flameproof
equipment, company-specified
components shall be used.
(d) Before starting to service the equipment,
be sure to check all parts necessary for
retaining the requirements for flameproof
equipment. For this, check that all screws,
bolts, nuts, and threaded connections have
properly been tightened.
(3) Prohibition of specification changes and
modifications
Do not attempt to change specifications or
make modifications involving addition of or
changes in external wiring connections.
References:
(1) Recommended Practices for Explosion-
Protected Electrical Installation in General
Industries.
(2) USER’S GUIDELINES for Installations for
Explosive Atmospheres in General Industry.
