Safety Considerations; General Requirements; Safety Checks; Installation - Eaton MTL7700 Instruction Manual

ETM7
ERL7
Figure 3: MTL7700 range of earthing accessories
Note: Module earth terminals may be used for cable
screen earth connections. See Figure 17
ERB57O Nickel-plated offset earth-rail bracket, supplied
with two push fasteners, one 14mm earth-rail
clamp and one 9mm earth clamp < 16mm
ERL7 Nickel-plated 3 x 10mm earth rail supplied in 1m
lengths. Provides earthing facilities for cable
screens and 0V earth returns, additional to
those provided on the module earth foot.
ETM7 Earth terminal (5mm wide) for attachment to an
ERL7 earth rail, for terminating cable screens
and spare cable cores.
3

SAFETY CONSIDERATIONS

3 .1

General requirements

All installers of shunt-diode barriers should be familiar with the
installation instructions provided by nationally accepted codes
of practice, eg, BS EN 60079-14 for the UK, or a recommended
practice, eg, ANSI/ISA-RP 12.6 for the USA.
Users within the European Community should also refer to the
supplied publication:
INA7700 MTL7700 range
Instructions for Safe Use
3 .2

Safety checks

Table 2 itemises the essential checks that should be carried out
to ensure the safety of a barrier installation. Use the checklist to
prevent important safety considerations being overlooked when
installing, commissioning, modifying or servicing an installation of
MTL7700 range of barriers. Check the list both before and after a
barrier system has been installed, the final check being made by
someone other than the person(s) who carried out the installation
work. Each item in the list is cross-referenced to the appropriate
section of the manual.
For Factory Mutual (FM) based installations see FM
certification information .
INM 7700 Rev 12
4
4 .1
MTL7700 range of barriers clamp directly onto standard T-section
DIN-rail (DIN EN 50 022). The simple mounting procedure for
barriers is described in section 4.2 and for accessories in section
4.3.
4 .1 .1
BEFORE mounting the barriers, make sure the rail length is
ERB57O
sufficient for the proposed number of barriers and for other
mounting accessories. As a guide, on a given length of DIN-rail,
allow space (length) for:
IMB57
a) Barrier packing pitch:
b) ETL7000 earth terminals:
ETL7000
c) IMB57 tagging strip support
THR2/THR7000
(if specified)
d) ISP7000 insulating spacer
ISP7000
(if specified)
e) ERB57S or O earth-rail
mounting bracket (if specified)
* See Note in section 4.3.2
Make sure that there is sufficient clearance between the DIN-rail
and any possible obstruction (eg, other columns of barriers) to
remove barriers and install accessories such as ERB57S/O earth
rails.
Provide sufficient height for IMB57 tagging strip supports and
2 .
ISP7000 insulating spacers when fitted.
As a guide, refer to figure 4 (dimensions of an individual barrier) and
figure 5 (clearances needed for accessories).
4 .2
MTL7700 range of barriers clamp directly onto T-section DIN-rail,
earthing the barrier through the rail.
a) Hook the hazardous-area end of the mounting/earthing clamp
over the hazardous-area flange of the DIN-rail (figure 6).
b) Push the safe-area end of the barrier firmly down by hand until
it clicks into place.
c) Check that the barrier is securely clamped into place (see
notes below).
d) To remove a barrier (figure 7), use the tip of a screwdriver (with
a blade width of 4 to 5mm, minimum shaft length 60mm) to
ease the metal clip at the base on the safe-area end outwards
until the barrier is freed and can be removed easily by
unhooking the hazardous-area end.
Notes
1: Make sure the barrier is properly clamped onto the rail to ensure
the essential earth connection. In a row of barriers, one end of an
improperly mounted barrier will stick up slightly.
2: Once an MTL7700 barrier is fitted, its mounting/earthing foot
grips the DIN-rail strongly in order to maintain positional stability
and create a high-integrity earth bond. The unit should not be forced
along the rail. If it is necessary to reposition a barrier, detach it from
the DIN-rail and re-attach it in the correct location. Where minor
repositioning is needed, relieve the pressure on the spring of the
mounting foot with a screwdriver and ease the unit into place.
4 .3
See section 2.3, figure 2 and figure 3 for brief details of the
accessories available for use with MTL7700 range of barriers.
More information and installation details (where relevant) for the
various accessories are detailed in the following sections:
Mounting accessories
Earthing accessories
3

INSTALLATION

General

DIN-rail length
12.6mm
10mm each (minimum of two)
16.0mm (minimum of two)
14.7mm (minimum of two)*
8 mm (minimum of two)

Mounting/removing barriers

Installing accessories

Section 4.3.1 to 4.3.
Section 4.3.3, 4.3.4