Safety instructions
12
VMD460-NA_D00001_05_M_XXEN/01.2020
2.3 Device-specific instructions
2.4 Intended use
The VMD460-NA voltage and frequency monitoring relay is used for network and sys-
tem protection (NS protection) of CHP plants, wind power stations, hydroelectric power
stations and photovoltaic systems feeding power into the network. If inadmissible volt-
age and frequency values occur on the supply side, the VMD460-NA disconnects the
generating plant from the public network by means of the interface switch.
In order to meet the requirements of applicable standards, customised parameter set-
tings must be made on the equipment in order to adapt it to local equipment and op-
erating conditions. Please heed the limits of the area of application indicated in the
technical specifications.
In the context of VDE-AR-N 4110:2018-11, the VMD460-NA can be used as decoupling
protection equipment for the generating unit or as higher-level decoupling protection,
the latter, however, only if the QU protection function (directional reactive power und-
ervoltage protection) may be dispensed with. According to VDE-AR-N 4110:2018-11
chapter 10.3.3.4 par. 5, this is possible after consultation with the network operator and
under the following conditions:
•
Generating plants with limited dynamic network support or
•
Generating plants < 1 MVA
Both types of application are possible when the generating plant is connected to the
busbar of a substation (MV-busbar) or when the generating plant is connected to the
medium-voltage network (MV-network).
Any other use than that described in this document is regarded as improper.
Unauthorised device access
After commissioning, the essential settings of the VMD460-NA have to
be protected against unauthorised changes by a password.
If the
password protection is not used, the device has to be sealed
.
Inspection
If the device is overloaded by overvoltage or a short-circuit current
load, it must be checked and replaced if necessary.
