64. Mounting of the device.The device is installable in places classified as Zone 1 or lower.When the device is installed, the prescriptions on the installation of intrinsically safe devicesmust be observed.The apparatus is available in wall-mountable or in instrument panel installable versions. In thecase of wall-mountable design the cables used for the electrical connecting of the device can beconnected through the stuffing boxes on the bottom of the device. After the housing of he de-vice is opened, four holes will become accessible on the back of the device near the corners.These holes are used for fixing the device on the wall. After the apparatus has been fixed to thewall, the connecting cables must be connected through the stuffing boxes to the terminal as-sembly. After the device has been assembled again, it can be switched on. When the panel-installable version is mounted, the relevant cables go through the stuffing boxes that are situat-ed on the back wall of the apparatus. After the housing of the apparatus has been opened, thehousing is inserted into the cut-out of the instrument panel (when the cut-out is designed, theouter dimensions presented by the following drawing must be taken into consideration). Thehouse is fixed by using the fastener fittings on the side walls. After the cables have been con-nected, the front cover is put back to its place, and fixed. Now the device can be switched on.Figure 3. Installation of the device5. Putting the device into operation.After the housing has been mounted to its place, and the device has been connected and as-sembled, the supply voltage of the apparatus can be switched on.After the device has been switched on, it performs a self-test. If the self-test is successful, thedevice sets itself to normal status (the value „0” is shown on the display). If the apparatus findsan error during the self-test, then the code indicating the error is shown on the display (e.g.„E1”). The explanation of the error codes is included in the following chapter.In programming mode all the optional outputs could be used in principle, however only the phys-ically installed outputs can be used in practice, therefore always check the data table of thedevice before connecting it, if the given option has been installed (analogue output, limit-valueoutputs)!