JUMO 707040 dTRANS T04 - 4-Wire Transmitter Operating Manual - Handbuch (Seite 44)

8
2 Installation
The device is not suitable for use in areas with an explosion
hazard (Ex areas).
With supply networks that are subject to interference (e.g.
thyristor control units), the transmitter should be fed from an
isolating transformer.
Supply fluctuations are only permissible within the specified
tolerances
1
.
The setup interface, the analog input and analog output are not
electrically isolated. This means that, in unfavorable conditions
and with a built-in transmitter, equalizing currents may flow
when the PC interface cable is connected. The equalizing
currents may damage the affected instruments.
However, there is no danger if the output circuit of the
transmitter is electrically isolated from ground. If it cannot be
ensured that, with a built-in transmitter, the output circuit is
electrically isolated, one of the following safety measures has to
be taken:
Use a PC that is not directly coupled to ground (e.g. battery-
operated notebook), or disconnect the output of the transmitter
before connecting the PC interface.
1
see Chapter 4 “Technical data”