Less Expensive Alternative to Ex d Indicators with Large Displays
BEKA associates have introduced two less expensive alternatives for flameproof Ex d loop powered indicators featuring large easy to read displays.
The new IECEx and ATEX certified Ex eb instruments can be installed in Zones 1 and 2 in exactly the same way as a conventional flameproof Ex d 4/20mA loop powered indicator. They do not have entity parameters and do not require a Zener barrier or galvanic isolator.
Both indicators have an increased safety Ex eb GRP enclosure that provides IP66 environmental and impact protection for the field wiring terminals and the encapsulated Ex m and intrinsically safe Ex i display assembly. The enclosure provides similar mechanical and chemical protection as a conventional metal flameproof enclosure and incorporates a large toughened glass display window and a tactile elastomeric keypad allowing control and calibration while the instrument is operating in the hazardous area.
These new indicators also have Ex tb certification permitting installation in Zone 21 & 22 dust hazardous areas. They may also be used as an alternative for Ex nA indicators in Zone 2.
The BA304SG has a 4 digit 34mm high display and the BA324SG has a five digit 29mm high display with a 31 segment bargraph. A factory fitted loop powered display backlight is available as an option.
Instruments can be supplied ready for installation. Calibrated to customer’s specification with the slide-in scale card printed with units of measurement and tag information plus if required customer’s company logo, all for no additional charge.
Additional information about this innovative multiple protection technique and how it has been used in these new indicators is contained in the BEKA Application Guide AG320, which may be downloaded from the BEKA website.