Siemens SINAMICS DCM Manual page 74

Voltage derating depending on the installation altitude
The series of SINAMICS DCM units fulfill overvoltage category III according to EN 61800-5-1
for line supply circuits with respect to the environment (other line supply circuits, housing,
electronics).
For electronics and field supplies with voltages of 2-ph. 480 VAC (line-to-line; maximum 300
VAC to ground), operation is permitted up to 4500 m above sea level. A maximum of 2-ph.
400 VAC (line-to-line; maximum 230 VAC to ground) is permitted up to 5000 m.
All units, with 400 V up to 575 V as well as also with 690 V to 950 V rated armature supply
voltage, can be operated up to a maximum of 4000 m above sea level without voltage
derating.
For units with rated armature supply voltages of 690 V to 950 V, up to 4500 m a maximum
930 VAC and up to 5000 m, a maximum 880 VAC is permissible as armature supply voltage.
For units with rated armature supply voltages of 400 V to 575 V, up to 4500 m a maximum
550 VAC and up to 5000 m, a maximum 500 VAC is permissible as armature supply voltage.
If the specified voltages with respect to ground are exceeded or the installation altitude is
exceeded, then a reduction of the overvoltage category to II must be applied. As a
consequence, operation up to 6000 m without derating is permissible.
The overvoltage category of the line supply can be reduced to II using an appropriate surge
arrester, filter or isolation transformer. If this is not realized, then there is no longer safe
electrical separation of the electronics (interface connections on the CUD) with respect to the
line supply.
According to EN61800-5-1, operation of units without "safe electrical separation" is only
permissible if it can be absolutely excluded that persons are in danger by being able to
directly touch or indirectly touch parts, i.e. in operation, none of the CUD interfaces can be
touched. A digital connection can be realized using an optical isolation.
SINAMICS DCM DC Converter
Operating Instructions, 02.2015, A5E34763375/RS-AA/001
ac.maher.co.ir
Technical data
4.4 Derating
75