BEKA BA377E-SS, Руководство пользователя

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A1.5 Installation in an Ex t panel enclosure
within Zone 21 or Zone 22.
Installation of a BA377E-SS Timer or Clock in an
Ex t panel enclosure does not invalidate the Ex t
panel's certification as the front of BA377E-SS
complies with Ex t impact and ingress requirements.
Although mounted in an Ex t panel enclosure, the
BA377E-SS remains Group II, Category
1D Ex ia IIIC T80ºC Da intrinsically safe apparatus
and therefore should be powered via a Zener barrier
or galvanic isolator as described in section 4.1 and
4.2 of this manual.
Fig 22 Typical installation in Ex t panel enclosure
The Zener barrier, galvanic isolator or associated
apparatus is usually installed in the safe area as
shown in Fig 22. It may be possible to mount the
intrinsically safe interface in the same Ex t panel
enclosure as the Timer or Clock if in normal
operation the outside temperature of the enclosure is
not affected.
The Timer or Clock terminals, the wiring to the Timer
or Clock 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 t 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'.