Installation - Modules; Modules - Pre-Installation - Eaton Crouse-Hinds Series Instruction Manual

INM 4500/4600 Rev 12
DRAFT - 22 March 2018
5 INSTALLATION – MODULES
• Work should be carried out in accordance with all relevant local standards, codes of
• Check that the hazardous-area equipment complies with the descriptive system
• Refer to the certificate/catalogue for clarification of any aspects of intrinsic safety or
contact Eaton's MTL product line or your local representative for assistance.
• Make sure the correct hazardous-area connector (field-wiring plug) is plugged into the
corresponding isolator. It is recommended that the connector is identified by the same tag
5 .1 Modules – pre-installation
5 .1 .1 Switch settings for operating conditions
Some modules have operating conditions, such as Line-Fault Detection (LFD), Phase
Reversal, etc., that can be established by the setting of switches on the unit. The
subminiature switches are accessible through an aperture on the side of the module (see
Figure 5.1) and can be set in the required positions with, for example, the blade of a small
screwdriver.
Figure 5 .1:
Location of
switches
The switch setting options are always indicated on the side label of the module, but the user
may also consult the individual module information in Section 6 of this manual for details.
5 .1 .2 Relay outputs
Reactive loads on all units with relays should be adequately suppressed. To achieve maximum
contact life on all mechanical output relays, the load should not be less than 50mW, e.g. 10mA
at 5V DC.
5 .1 .3 Ambient temperature considerations
The MTL4500 range of isolators are rated for an ambient operating temperature range of
–20°C to +60° even when they are mounted (close-packed) on a backplane, except where
otherwise noted.
5 .1 .4 Module and backplane orientation
The orientation of the backplane will have an influence on the amount of air flow through
and around the modules, so this must be considered if this operating temperature range is
to be maintained. There are two main orientations for the backplanes, as shown in Figure 5.2.
Although orientation b), where the modules are aligned in a vertical plane, is the optimum for
heat transfer, orientation a), where the modules are horizontal, is the most frequent because it
is probably the most convenient for cabling.
5 .1 .5 Cabinet and enclosure mounting
The backplanes are normally mounted with other equipment in an enclosure or wiring cabinet,
so particular consideration must be given to the management of the internal temperature and
the need to remove heat from around the modules. Space around the modules is essential for
the free movement of air and adequate ventilation is required for its removal.
The larger the source of heat, the higher it should be mounted in the cabinet, this is in order
to avoid the creation of an undesirable temperature gradient from the bottom of the cabinet to
the top.
Principal sources of heat in such circumstances are ac/dc power supplies for the internal
equipment. These should certainly be located at the top of the cabinet to limit the effect of their
dissipated heat.
IMPORTANT
practice and site regulations.
document.
number as the matching isolator.
1 2 3 4
OFF position
ON position
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