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15
Electricity
+
Control
AUGUST 2017
ELECTRICAL PROTECTION + SAFETY
turing, the surge protective devices (SPDs) should
take up as little space as possible. The goal is to
centralise numerous service functions − such as
system monitoring − in the control room. To oper-
ate the system safely from an EMC perspective,
SPDs are implemented in large systems.
Protection in a confined space
Numerous channels often have to be housed with-
in a small area in order to transmit analogue or
digital signals. Since space is becoming increas-
ingly valuable, the narrowest components of this
product range have a width of only 3,5 mm. The
components of Termitrab complete are equipped
with six terminal points to which two signal lines
each and a common reference potential can be
connected.
With this extremely compact and narrow con-
tactor, which is being made available on the world
market for the first time, up to 572 signal lines
can be protected on one metre of DIN rail (see
Figure 2
). The power dissipation has been mini-
mised significantly as well, due to the decoupling
resistors in the protective circuits. This feature also
aims to satisfy the demand for installing more de-
vices in increasingly smaller spaces.
Figure 2: 572 signals per metre: With its extremely
narrow components, Termitrab complete saves a great
deal of space in the control cabinet.
The lightning protection standards recommend
regular inspection of protective devices. This is
only possible through visual examination. The Ter-
mitrab complete product range features a status
indicator that displays an overload of the surge
protection directly on the device. Since no addi-
tional power is needed for this indicator, the pro-
tective device also displays the fault continuously
during an overload. If this information is displayed
in a control room, the optionally available ‘remote
signalling modules’ (see
Figure 3
) ensure the nec-
essary data transmission.
Either the PLC (programmable logic control-
ler) can query the potential-free contact directly
by wire, or this contact is integrated by interface
modules, with, for example, the compact mes-
sage system TC Mobile I/O X200. This means
that the status of the protective devices in large
systems can be monitored not only in the control
room, but also sent via SMS to the cell phone of
the service technician. If a contactor is overloaded,
trouble-free replacement is possible, in particular
with the pluggable protective devices.
Figure 3: Integrated status indicator: Thanks to the surge
protection components of Termitrab complete, the user
is kept up-to-date regarding the state of their system at
all times.
Permanent installation with push-in
technology
Classical screw connection technology is still com-
monly used. If there are many signal lines to be
installed however, considerable time can be saved
with the quick push-in connection technology (see
Figure 4
). Comparisons with screw connection
technology have shown, for example, that the
wires can be connected up to 50% quicker. Dis-
connection is also easily possible by pressing the
‘pusher’. Depending on his preference, the install-
er can choose between screw and push-in con-
nection technology with the Termitrab complete
product range.
Figure 4: Convenient connection:
Conductors can be connected quickly
with push-in technology and removed
without any special tools.
In water and wastewater
treatment, there is an
increased failure risk in
large systems due to surge
voltages – with far-reaching
consequences.