BEKA BA337E-SS, Руководство пользователя

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Some Zener barriers and galvanic isolators are
certified for mounting within a protective enclosure
located in Zone 2 which may permit them to be
mounted in the same Ex e enclosure as the
BA337E-SS Rate Totaliser. Zener barriers and
galvanic isolators are not permitted in Ex e enclosures
located in Zone 1.
The Rate Totaliser terminals, the wiring to the Rate
Totaliser and the intrinsically safe interface, if mounted
within the enclosure, should be segregated from all
other non-intrinsically safe wiring and equipment
within the panel enclosure as required by EN
60079-11
Equipment protected by intrinsic safety and
EN 60079-14 Electrical installations design, selection
and erection .
The Ex e panel enclosure should be fitted with a
warning label saying 'Do not open when non-
intrinsically safe circuits are energised', alternatively
all bare live non-intrinsically safe parts within the
panel enclosure should have an IP30 cover carrying a
warning label 'Do not open when energised'.
The power dissipation within an BA337E-SS fitted with
operational alarms and a backlight is normally about
350mW. In the very unlikely event that all three
circuits fail to the worst case condition at the same
time, the total power dissipation rises to 2.5W which
could raise the internal temperature of a small
thermally well insulated panel enclosure.
4.3.2 Installation in Ex p panel enclosure within
Installation of a BA337E-SS Rate Totaliser in an Ex p
IIC Gb or Ex p IIC Gc pressurised panel enclosure
does not invalidate the Ex p panel's impact and
ingress protection as the front of the Rate Totaliser
complies with Ex p impact and ingress requirements.
Although mounted in an Ex p panel enclosure, the
BA337E-SS remains Group II Category 1G Ex ia IIC
T5 Ga intrinsically safe apparatus and must therefore
be powered via a Zener barrier or galvanic isolator as
described in section 4.1 and 4.2 of this manual to
ensure that the instrument's front panel push button
switches are nonincendive.
When installed in an Ex p panel enclosure the four
vents at the rear of the Rate Totaliser which are shown
in Fig 10 should not be obstructed.
Zener barriers and galvanic isolators may be installed
in the same Ex p enclosure as the BA337E-SS. All
may be mounted in an Ex px enclosure installed in
Zones 1 or 2, or in an Ex pz enclosure installed in
Zone 2, both of which have a non-hazardous interior.
Some Zener barriers and galvanic isolators may have
certification permitting installation within an Ex py
enclosure which has a Zone 2 interior.
The Rate Totaliser's terminals, the wiring to the Rate
Totaliser and the intrinsically safe interface, if mounted
within the enclosure, should be segregated from all
other non-intrinsically safe wiring and equipment
within the panel enclosure as required by EN 60079-
11
Equipment protected by intrinsic safety and EN
60079-14 Electrical installations design, selection
and erection .
If live maintenance is anticipated, it is recommended
that the Ex p panel enclosure should be fitted with a
warning label saying 'Do not open when non-
intrinsically safe circuits are energised', alternatively
all bare live non-intrinsically safe parts within the
panel enclosure should have an IP30 cover carrying
a warning label 'Do not open when energised'.
Fig 7 Typical installation in Ex p panel enclosure
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