2
INM4500-2
Mar 2009
2.1 Standard
backplanes
MTL4500 series standard backplanes, with quick-release clip connectors, accommodate 4, 8, 16 or
24 modules. The backplane carries the safe-area signals and distributes dual-redundant 24V dc power
supplies with three-point status monitoring. In applications where a number of 8- and 16-way backplanes
are installed, the power supplies can be interconnected. Optional earth-rail kits are available for 8- and
16-way backplanes and tagging-strip kits are available for all backplanes.
2.2 Customised
backplanes
If the backplane is to be mounted in a safe area (which is the most common type of application) then
it does not need to be certified, because the hazardous area wiring connects to the I/O modules,
not
the backplane
. This means that non-hazardous area backplanes can be produced easily by MTL, or the
user, and can be designed to match exactly the size, shape, method of mounting, type of connector, pin
assignments, etc, of a particular process system. Please contact MTL for further information.
When mounting the back plane in Zone 2/Div 2 hazardous areas the MTL web site should be consulted
for documents detailing any approvals.
2.3 Accessories
Accessories are available that enable the user to mount standard MTL backplanes. These include surface-
mounting kits, T-section and G-section DIN-rail mounting kits and end stops and a horizontal plate for
mounting 24-way backplanes in 19-inch racks.
3 INSTALLATION
–
PRECAUTIONS
3.1 General
Please read this section before beginning to install backplanes, enclosures, modules etc.
3.2 Precautions
Make sure that all installation work is carried out in accordance with all relevant local
standards, codes of practice and site regulations.
Check that the hazardous-area equipment complies with the descriptive system document.
If in doubt, refer to the certifi cate/catalogue for clarifi cation of any aspects of intrinsic safety,
or contact MTL or your local MTL representative for assistance.
Check that the interface unit(s) function(s) are correct for the application(s).
When plugging modules into backplanes and hazardous-area connectors into modules, check
the identifi cation labels to make sure the items match correctly.
4
INSTALLATION – BACKPLANES AND ENCLOSURES
4.1 Backplanes – mounting
See Table 4.1 for listings of the mounting methods and kits and accessories applicable to MTL standard
backplanes and Figure 4.1 for dimensions and mounting centres.
4.1.1 Surface mounting – with SMS01 mounting kit
Refer to Figures 4.1 and 4.2.
Drill mounting surface at centres A (Figure 4.1) and tap, or fi t retaining nuts if required.
Select the appropriate number of M4 x 20mm screws for the size of backplane
(4 for a 4-way and 8-way, 6 for a 16-way and 8 for a 24-way backplane).
Fit each M4 x 20mm screw (1) with a locking washer (2) and a plain washer (3) (Figure 4.2).
Insert the screws through the backplane at each mounting centre A.
Fit each with an M4 x 10mm spacer (5) and a retaining washer (6) (Figure 4.2).
Attach the assemblies to the prepared surface using a suitable nut if the holes are not tapped.
a)
b)
c)
d)
e)
a)
b)
c)
d)
e)
f)
