Sirius 3Rf34 Solid-State Switching Devices; Safety Instructions - Siemens SIRIUS 3RT Series System Manual

SIRIUS 3RF34 solid-state switching devices

3.1

Safety instructions

Correct usage
NOTICE
Radio frequency interference in residential areas
This product is a Class A device. Its use in residential areas can cause radio frequency
interference.
In this case, the user can be held liable for taking additional measures to attenuate such
interference.
Safety measures
Inter-phase short circuit due to overvoltage on solid-state reversing contactors
In the event of a short circuit, the switching devices in the load feeder can put persons and
property at risk.
For fused configurations, the protective device has to be replaced following a short circuit.
To reduce the risk of an inter-phase short circuit due to overvoltage, we recommend
connecting a 3TX7 462-3L type varistor between L1 and L3. We recommend a fused
design with semiconductor protection to provide short-circuit protection.
NOTICE
Inter-phase short circuit with solid-state reversing contactors in automatic mode
If the primary voltage is applied at the solid-state reversing contactors at the same time as
the control voltage is switched on, the integrated RC surge suppressor may respond in
some cases. If it does, dependent on actuation, two thyristors in the reversing circuit may
activate, thereby producing an inter-phase short circuit.
To be sure of avoiding this response, once the primary voltage has been applied, a delay of
40 ms should be allowed to elapse before the control inputs are activated.
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
CAUTION
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