Electrical Installation; General; Maximum Length Of Motor Cables; Operation With Ungrounded Systems - Siemens SED2 series Operating Instructions Manual

Danger
Danger
. . . .
Note
IP20/NEMA 0
IP54/NEMA 12
Important
Siemens Building Technologies
HVAC Products
4

Electrical installation

The VSD must be grounded.
♦
To ensure safe operation of the equipment, authorized persons must install and
commission it in full compliance with the notes and warnings set out in these
operating instructions.
♦
Take particular note of general and regional installation and safety regulations
regarding work on sites with dangerous voltages (e.g. EN 50178), and of the
relevant regulations for the correct use of tools and personal protective equipment.
♦
The cross-section of the ground bonding conductor must be at least equal to that of
the mains connection cables.
Dangerous voltages may occur at the following terminals even when the
variable speed drive is not running:
- Power supply terminals L1, L2, L3.
- Motor terminals U, V, W, DC+, DC-.
- Link terminals DC-, DC+/B+, DC/R+, B-.
After switching off the supply voltage, wait at least 5 minutes before starting any
installation or service work.

4.1 General

4.1.1

Maximum length of motor cables

The performance data given in the specifications cannot be guaranteed if the motor
cables exceed the following lengths:
For devices featuring EMC filters, the maximum cable length is 25 m. For cables
shorter than > 25 m, the EMC guideline for filtered devices does not apply.
If you connect several motors to one VSD, the individual motor lines must be added to
the total line length.
4.1.2

Operation with ungrounded systems

SED2 variable speed drives with a protection standard of IP20 operate in ungrounded
systems, and remain in operation when an input phase connects to ground. In the
event of an output phase with a ground fault, the SED2 switches off and displays
message F0001.
SED2 drives with a protection standard of IP54/NEMA 12 cannot be operated in
ungrounded systems.
4.1.2.1

Precautions for ungrounded systems (IT protective systems)

In ungrounded systems, remove the Y capacitor, or break the connections to this
capacitor and integrate an output choke. The following procedure shows how to remove
or disconnect the capacitor.
Operation in ungrounded systems is possible only using the SED2, IP20, without
filter.
SED2 variable speed drives
Electrical installation
50 m for shielded cables
100 m for unshielded cables
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CM1U5192en
01.2002