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EX-B03E

• Speciﬁ c cables shall be used as recommended by the

“USER’S GUIDELINES for Electrical Installations for

Explosive Gas Atmospheres in General Industry,” published

in 1994.

• In necessary, appropriate protective pipes (conduit or ﬂ exible

pipes), ducts or trays shall be used for preventing the cable

run (outside the cable glands) from damage.

• To prevent explosive atmosphere from being propagated

form Zone 1 or 2 hazardous location to any different

location or non-hazardous location through the protective

pipe or duct, apply sealing of the protective pipes in the

vicinity of individual boundaries, or ﬁ ll the ducts with sand

appropriately.

• When branch connections of cables, or cable connections

with insulated cables inside the conduit pipes are made,

a ﬂ ameproof or increased-safety connection box shall be

used. In this case, ﬂ ameproof or increased-safety cable

glands meeting the type of connection box must be used for

cable connections to the box.

(2) Flameproof Metal Conduit Wiring

• For the ﬂ ameproof metal conduit wiring or insulated

wires shall be used as recommended by the USER’S

GUIDELINES for Electrical Installations for Explosive Gas

Atmospheres in General Industry, published in 1994.

• For conduit pipes, heavy-gauge steel conduits conforming to

JIS C 8305 Standard shall be used.

• Flameproof sealing ﬁ ttings shall be used in the vicinity of

the wiring connections, and those ﬁ ttings shall be ﬁ lled with

sealing compounds to complete sealing of the apparatus.

In addition, to prevent explosive gases, moisture, or ﬂ ame

caused by explosion form being propagated through the

conduit, always provide sealing ﬁ ttings to complete sealing

of the conduit in the following locations:

(a) In the boundaries between the hazardous and non-

hazardous locations.

(b) In the boundaries where there is a different classiﬁ cation

of hazardous location.

• For the connections of the apparatus with a conduit pipe or

its associated accessories, G-type parallel pipe threads (JIS

B 0202) shall be used to provide a minimum of ﬁ ve-thread

engagement to complete tightness. In addition, since these

parallel threads do not have sealing property, non-hardening

sealant such as liquid gaskets shall thus be applied to those

threads for ensuring waterproofness.

• If metal conduits need ﬂ exibility, use ﬂ ameproof ﬂ exible

ﬁ ttings.

6. Maintenance of Flameproof Apparatus

To maintain the ﬂ ameproof apparatus, do the following. (For

details, see Chapter 10 “MAINTENANCE OF EXPLOSION-

PROTECTED ELECTRICAL INSTALLATION” in the USER’S

GUIDELINES for Electrical Installations for Explosive Gas

Atmospheres in General Industry.)

(1) Maintenance servicing with the power on.

Flameproof apparatus 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 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 ﬂ ameproof apparatus, 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. In doing this, great care must be taken not

to cause mechanical sparks with tools.

(2) Repair

If the ﬂ ameproof apparatus requires repair, turn off the power

and transport it to a safety (non-hazardous) location. Observe

the following points before attempting to repair the apparatus.

(a) Make only such electrical and mechanical repairs as will

restore the apparatus to its original condition. For the

ﬂ ameproof apparatus, 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 transmitter

and terminal box, shrouds or clamps, or external wiring

connections which are essential in ﬂ ameproofness, contact

Yokogawa Electric Corporation.

CAUTION

Do not attempt to re-process threaded connections or reﬁ nish

joints or mating surfaces.

internal mechanisms may be repaired by component

replacement, as this will not directly affect the requirements

for ﬂ ameproof apparatus (however, bear in mind that the

apparatus must always be restored to its original condition).

If you attempt to repair the ﬂ ameproof apparatus, company-

speciﬁ ed components shall be used.

(d) Before starting to service the apparatus, be sure to check all

parts necessary for retaining the requirements for ﬂ ameproof

apparatus. For this, check that all screws, bolts, nuts, and

threaded connections have properly been tightened.

(3) Prohibition of speciﬁ cation changes and

modiﬁ cations

Do not attempt to change speciﬁ cations or make modiﬁ cations

involving addition of or changes in external wiring connections.

7. Selection of Cable Entry Devices for Flameproof

Type

IMPORTANT

The cable glands (cable entry devices for ﬂ ameproof type)

conforming to IEC Standards are certiﬁ ed in combination

with the ﬂ ameproof apparatus. So, Yokogawa-speciﬁ ed cable

entry devices for ﬂ ameproof type shall be used to meet this

demand.

References:

(1) Type Certiﬁ cate Guide for Explosion-Protected Construction

Electrical Machinery and Equipment (relating to Technical

Standards Conforming to International Standards), issued by

the Technical Institution of Industrial Safety, Japan

(2) USER’S GUIDELINES for Electrical Installations for

Explosive Gas Atmospheres in General Industry (1994),

issued by the Japanese Ministry of Labour, the Research

Institute of Industrial Safety.