Rugged panel mounting indicators may be safely installed in Ex e cabinets

Thanks to a new range of BEKA rugged panel mounting indicators, it is now possible to safely install 4/20mA loop powered indicators in Ex e increased safety and Ex p pressurised cabinets located in Zones 1 or 2 and in Ex n cabinets located in Zone 2 without invalidating the cabinet”s certification.
Housed in a 316 stainless steel cast case with an impact resistant front, these IECEx and ATEX certified indicators significantly reduce installation complexity and cost. The instrument certificates include details of where the indicator may be safely installed.

For applications in Zone 2 the Ex nA indicators eliminate the need for a Zener barrier or galvanic isolator, allowing direct connection to a 4/20mA current loop within the enclosure. To assist system design, installation and maintenance of extra low voltage Ex nA certified instrumentation, BEKA have published Application Guide AG310 which may be downloaded from the BEKA website.
This recommends how Ex nA instrumentation should be installed and includes a section dedicated to the use of these new rugged Ex nA panel indicators.
For installation in Ex e and Ex p enclosures located in Zone 1, rugged intrinsically safe Ex ia models are available supported by Application Guide AG300 which may also be downloaded from the BEKA website.
This new rugged range includes models with four 15mm high digits, or five 11mm high digits plus a 31 segment bargraph. All have an operating temperature between –40oC and +70oC and include a square root extractor, sixteen segment lineariser and a tare function. Optional factory accessories include a backlight that may be loop or separately powered and dual alarms with isolated solid state outputs.
The indicators have an IP66 front panel and a captive gasket seals the joint between the instrument and the cabinet allowing them to be washed down. A novel scale card showing the units of measurement in a window adjacent to the display may be changed on-site without opening the instrument enclosure or removing it from the cabinet.