Metrohm NIRS XDS Process Analyzer – SingleFiber - Manual (Page 14)

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2
Purged System for Hazardous Environments
The XDS Process Analytics Instrument offers the
option of a BEBCO purging system for
hazardous environment use. This compact
purging system is designed to meet European
approvals as well as North American standards.
The system permits use of the XDS Process
Analytics Instrument in Div. 1 areas as defined
under NEC 500 standards, and in Zone 1 areas
as defined by IEC/CENELEC and NEC 505
requirements.
The BEBCO system supplies clean instrument air
or inert gas, to remove flammable gases and
prevent accumulation of ignitable dusts within
the protected XDS Process enclosure. The XDS
Process Analytics Instrument is therefore
protected against combustion, heat, moisture,
dust build-up and corrosion.
The specific system supplied is the BEBCO 4003 Type X, which is rated for enclosure volumes of up to
90 cubic feet, or 2.5 cubic meters. Actual volume of the XDS Process Analytics Instrument is
approximately 3.1 cubic feet.
Enclosure purging systems offer a safe and practical means of installing electrical equipment in
hazardous locations, eliminating the need for explosion-proof boxes and intrinsic safety barriers.
This manual gives basic information on use of the Type X Purge System. More detailed information is
available on the BEBCO web site,
http://www.okbebco.com/PDFs/4003-4r10.pdf .
The following information on Pressurization and Class Types is helpful in understanding the nature of
hazardous locations and types of protection required:
2.1
Pressurization “Types”
The NFPA and ISA define “Types” of pressurization based on the Division rating of a hazardous
location and electrical ratings of the protected equipment. This is because general purpose and
Division 2 rated electrical equipment require different means of protection, depending on their
location.
Type “X”
PROTECTS GENERAL PURPOSE EQUIPMENT IN DIVISION 1 AREAS
This system reduces the classification within protected enclosures from Division 1 to non-classified. It
is required to automatically control electrical power to all protected equipment.
Purging
COMMON EQUIPMENT IN CLASS I AREAS
As strictly defined by NFPA 496, this method is a start-up process of Class I area pressurizing which