Siemens SIMOVERT Master Drives 6SE70 Betriebsanleitung Seite 263

09.02
The permissible output current for a parallel arrangement is reduced (due to the current division between the
power sections) by 10% as compared with the sum of the rated currents of the separate power sections.
The following is required to ensure even current distribution between the basic unit and parallel unit(s).
♦ Use of identical power components (see above table for the corresponding parallel units and basic unit)
♦ Identical phases for the power section connections of the common rectifiers between the basic units and
parallel unit(s)
♦ Commutating reactors specific for each basic and parallel unit with identical technical data. Each separate
parallel path must have a minimum u k value of 2%!
Mains
♦ Identical fuses for basic unit and parallel unit(s)
♦ Identical cable lengths leading to the power section connections of the basic and parallel units
Output reactors in the DC circuit are not permitted.
The maximum permissible total cable length between the basic unit and parallel unit 1 or parallel unit 2 (if
present) is 15 m.
A 50-way shielded round cable with a length of 4 m is contained in the scope of supply of a parallel unit (spare
parts order No.: 6SY7010-8AA00).
Order No. for one cable "10 m round, screened": 6QX5368 (other lengths on request):
On connecting this round, 50-core cable with a diameter of 14 mm, its screen has to be laid bare by cutting
away the insulation and it must be connected to earth on both devices. With regard to the immunity to
interference of the system, it is recommended that the cable be installed in a separately earthed shielded cable
duct.
The cable length within the unit from the connector on the A23 module (X27 or X28) to the top edge of the unit
on the rear panel (cabinet wall) is 1m to the left and 1.8 m to the right. This includes the spare length required
for removing the A23 module with its carrier board for service purposes.
Siemens AG 6SE7087-6AK85-0AA0
Common Rectifier Operating instructions
NOTES
Fault-free operation can only be guaranteed if the phases at the power section
terminals (U1/L1, V1/L2, W1/L3, C/L+ and D/L-) between the basic unit and
parallel unit(s) are identical.
Non-compliance with this condition may result in destruction of the power
sections of the basic and parallel units.
Basic unit
X117 X27
X28
Parallel unit (1)
X27
X28
Parallel unit 2
WARNING
DC link
ENGLISH
Connection
3-19