High voltage warning
The voltage of the frequency converter is
dangerous whenever the equipment is
connected to mains. Incorrect installation
of the motor or frequency converter may
cause damage to the equipment, serious
injury or death. Comply with the instruc-
tions in this manual, as well as national
and local rules and safety regulations.
Touching the electrical parts may be fatal
- even after the equipment has been dis-
connected from mains: Wait at least 4
minutes for current dissipate.
NB!
It is the responsibility of the user or instal-
ler to ensure correct earthing and protec-
tion in accordance with national and local
standards.
Earthing
Comply with the following at installation:
•
Safety earthing: The drive has a high leakage
current and must be earthed properly for
safety. Follow all local safety regulations.
•
High frequency earthing: Keep earthing con-
nections as short as possible.
Connect all earthing SYSTEMs to ensure the lowest
possible conductor impedance. The lowest possible
conductor impedance is achieved by keeping the con-
ductor as short as possible and by grounding with the
greatest possible surface area. If multiple drives are
installed in a cabinet, the cabinet backplate, which
must be made of metal, should be used as a joint earth
reference plate. The drives must be fitted to the back-
plate at the lowest possible impedance.
To achieve low impedance, connect the drive to the
backplate with the drive fastening bolts. Remove all
paint from the contact points.
Cables
The control cable and the mains cable should be in-
stalled separately from motor cables to prevent noise
transfer. As a rule a distance of 20 cm is sufficient, but
it is recommended that the distance is as great as pos-
sible, particularly when cables are installed in parallel
over large distances.
For sensitive signal cables such as telephone or data
cables the greatest possible distance is recommen-
ded. Please note that the required distance depends
on the installation and the sensitivity of the signal ca-
bles, and that for this reason exact values cannot be
given.
When being placed in cable trays, sensitive cables
may not be placed in the same cable tray as the motor
cable. If signal cables run across power cables, this is
done at an angle of 90 degrees. Remember that all
noise-filled inlet and outlet cables to a cabinet must be
screened/armoured.
See also
EMC-compliant electrical installation
.
Screened/armoured cables
The screen must have low HF impedance, which is
achieved by a braided screen of copper, aluminium or
iron. Screen reinforcement intended for mechanical
protection, for example, is not suitable for EMC-correct
installation. See also
Use of EMC-correct cables
.
Extra protection
RCD relays, multiple protective earthing or earthing
can be used as extra protection, provided that local
safety regulations are complied with. In the case of an
earth fault, a DC content may develop in the faulty cur-
rent. Never use an RCD (ELCB relay), type A, as it is
not suitable for DC faulty currents. If RCD relays are
used, local regulations must be complied with.If RCD
relays are used, they must be:
-
Suitable for protecting equipment with a DC
content in the faulty current (3-phase bridge
rectifier).
-
Suitable for a pulse-shaped, brief discharge
on power-up.
-
Suitable for a high leakage current.
N must be connected before L1 for single phase 200
V reduced leakage current units (type code R4).
High voltage test
A high voltage test can be performed by short-circuit-
ing terminals U, V, W, L1, L2 and L3, and applying
max. 2160 V DC in 1 sec. between this short-circuit
and terminal 95.
42
MG.27.E2.02 - VLT is a registered Danfoss trademark
