8VG12_D00032_03_M_XXEN/01.2019
3. System description
3.1 Protective measures for mobile generators
The VG12 safety distributor is intended for the practical implementation of the protec-
tive measure "Protective separation with insulation monitoring and disconnection"
specified in section 551.4.4.2 of the standard DIN VDE 0100-551.
The voltage supply is designed in a way that protective separation is realised with more
than one load. The continuously measuring ISOMETER® switches off the mains voltage
if the value falls below the response value. This results in the following characteristics:
No earth spike
High-resistance insulation faults are detected immediately. When reaching the
response value, the socket-outlets of the VG12 are switched off.
(DIN VDE 0100-410, Annex C3)
Suitable only for operation and monitoring by electrically skilled or instructed
persons.
The exposed conductive parts of the whole generator circuit must be connected
by insulated, unearthed protective equipotential-bonding conductors PA (see
schematic wiring diagram on Page 15).
Such conductors must not be connected to the protective conductors or exposed
conductive parts of other circuits or to any other conductive parts.
An ISOMETER® measures the sum of all insulation faults in the system, i.e. the absolute
insulation value.
Page 21 provides a list of all relevant standards.
3.2 Prerequisites for use
The protective measure "Protective separation with insulation monitoring and discon-
nection" avoids hazards from indirect contact with parts carrying voltage due to faults
in the basic insulation of the circuit.
The power generator must supply a single-phase AC voltage of 230 V. Tolerances
according to IEC 38 are permissible. Higher voltages may destroy components of
the safety distributor. Hence, the protective function may be disabled.
The maximum load current must not exceed 16 A. Higher load currents may
destroy the contacts of the connection plug of the VG12 safety distributor and
thus disable the protective function.
