INM 937x-FB2-Px-SS Rev 1
12
4 .5 Trunk Surge protection module 9376-SP
The 9376-SP Trunk Surge protection module can be fitted to the TTA to prevent
damage to the equipment from voltage and current surges that could occur on the
trunk wiring.
The 9376-SP is a four pin module that plugs into the upper end face of the Trunk
Terminator Assembly. See Section 5.3 for fitting and removal details.
4 .6 Spur connections
The spur cables can be connected directly onto the fieldbus barrier carrier terminals
or, for additional protection from current surges, be connected through a Spur Surge
module (FS32) as shown in Figure 4.7.
(Note that the connectors shown in this figure
are screw-terminal type.)
If Spur Surge modules are not being used, ignore sub-section 4.6.2.
Figure 4 .7
– FS32 Spur Surge module on carrier
4 .6 .1 Connecting the spur cables
Prepare the spur cables in accordance with the gland manufacturer’s instructions and
secure each cable in a suitable gland in the enclosure wall.
IMPORTANT
• When fitting the cable in the gland allow 20 – 30mm of additional cable length
outside the enclosure to allow for adjustment if a Spur Surge module is taken
out of circuit inside the enclosure. See Section 5.4.1 for further details
• Cable ferrules must be fitted to any stranded cable or screen wiring that is
being used.
• Connect the prepared ends of the fieldbus spur cables into the ‘+’, ‘S’ and ‘–’
terminals on the carrier (or surge module, if fitted), making sure that the same
polarity is observed for all spurs.
4 .6 .2 Fitting FS32 Spur Surge modules
Spur Surge modules are pluggable units that integrate easily with the standard
pluggable connector and which direct excessive spur surge currents to the protective
local ground.
To fit an FS32:
1. Unscrew the two captive screws securing the standard pluggable connector
(supplied on the carrier) and remove it from its socket.
2. Insert the FS32 module into the now vacant socket on the carrier, tighten
the two side securing screws and the central “protective ground” screw, to a
recommended torque of 0.4 Nm.
3. Fit the connector (removed at Step 1 above) into the socket on the FS32 and
tighten its two securing screws also to a recommended torque of 0.4 Nm.
4. Removal of a Spur Surge module is the reverse of the fitting process. See
also Section 5.4.1 on page 14 for information on cable ‘adjustment’ if one of
these modules is taken out of use.
