ATEX & IECEx Gas & Dust certified solutions for Zebra ZT 411 (4”) and ZT 421 ( 6”)industrial label printers
Advantages
Hazardous area solution for industry standard label printing —systems for 4” and 6” label sizes availa-ble
ATEX/IECEx Zone1/21 and 2/22 certified for gas or dust using Expo’s proven Ex p capability
Power and signal safety interlocked for full code compliance
316L stainless steel enclosure for industrial & ultra-clean environments
Description
Printers for bar code and batch number labels are found in many industrial locations. If the printer is to be located in a hazardous area, then a certified solution is required to en-sure safe operation. Due to operational requirement & constraints, many of the possible Ex protection concepts are not suitable. Ex p (Purge & Pressurization) provides the most flexible and cost-effective solution. Expo has worked with Zebra Technologies, a leading manu-facturer of industrial label printers to develop a standard certified solution based around their popular ZT400 series.
What is Purge and Pressurization (Ex p)?
A two-step process that is required prior to energizing elec-trical equipment inside a suitable leak-tight enclosure. Using instrument quality air, the enclosure is first purged for a set time. This time is calculated based on the enclo-sure dimensions and the number of volume changes re-quired by the certificate. After successful completion of the purge sequence, the enclosure is maintained at a set over-pressure (typically 5 mbarg) and the electrical equipment can be energised. This process must be controlled and monitored by a certi-fied purge & pressurization system that can energise/de-energise the system as required.
Expo’s certified solution
The printer is installed inside a robust stainless steel en-closure. The system is fitted with a purge system to con-trol and monitor the purge & pressurization process, and an isolation unit to provide power and ethernet control. While the overall system is standard, the internal mounting arrangements are adaptable to house either Zebra printer model. Expo’s design incorporates several unique features:
Through-the-enclosure-wall pushbuttons to actuate the printer membrane switches for label feed control
A clear window to view the printer display screen
A low leakage, anti-static label slot to permit label exit while maintaining positive pressure inside the enclo-sure.
The printer sits on an adjustable, sliding internal tray allowing accurate alignment for the label feed and pushbuttons. A side access door is provided for print media roll change.
The system has three mounting configurations: table top; wall-mount or plinth-mount.
ATEX: II 2 G D Ex pxb IIC T4 Gb; Ex pxb IIIC T135℃ Db Tamb 5 to 30℃ IECEx: Ex pxb IIC T4 Gb; Ex pxb IIIC T135℃ Db
