thuba TMS Manuel page 27

Manual PTB 24 ATEX 1001 X
5.12 Terminals for earthing or equipotential
bonding
Particular attention must be paid to the con-
nections for protective conductors.
The metal enclosures are fitted with an internal
and an external connection for the earth conduc-
tor (PE) or the equipotential bonding conductor.
The number of terminals provided for the PE
must be at least equal to the number of circuits.
The minimum permissible cross section of the
PE terminal is shown in Table 4 as a function of
the maximum permissible cross section of the
associated phase and neutral terminals.
Inner and outer equipotential bonding terminals
are provided as secure connections for the
equipotential bonding conductor. These are
dimensioned for a minimum cross section of 4
mm², depending on the version.
Maximal permissible cross
section of the phase or
neutral terminal
2
S [mm ]
≤ 16
Table 4: Minimum cross section of the PE conductor
terminal
5.13 Foreign objects and dust
All foreign objects must be removed from the
explosionproof enclosure of the temperature
controller and safety temperature limiter before
the initial start-up of the instrument. Should any
dust have entered the enclosure, it must be
cleaned before the instrument is put into service.
6. Initial start-up
The correct functioning of the temperature con-
troller and safety temperature limiter with its
associated interlock in the control system must
be verified and documented.
Mixing up the heating and cooling connec-
tions will result in dangerous malfunctioning
of the system!
Edition April 2024
Copyright
Minimum cross section of
the associated protective
conductor terminal
2
Sp [mm ]
S
21
thuba Ltd., CH-4002 Basel
Switzerland