ABB ACS 800 Series User guide

ACS800
Application Guide
ACS800 Single Drive Common DC Configurations

ACS800 Single Drive Common DC Configurations
Application Guide
3AFE64786555 REV E
EN
EFFECTIVE: 03.12.2004
2004 ABB Oy. All Rights Reserved.

5
Table of contents
Introduction
Possible main supply connections
Step by step guide
Design
Power limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Allowed braking power and need for a brake resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Calculation of the allowed braking power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Internal brake chopper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
External brake chopper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Contactors, DC bus and brake circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Wiring
Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Powering the AC fans in R7 and R8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Brake resistor circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Connecting the contactor of the resistor circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Phase loss guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
READY signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Wiring the READY signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Start-up
Appendix A Charging circuit capacity
Frame sizes R...R4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Frame sizes R5...R8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Appendix B Powering the AC fans of R7 and R8

6

Introduction
7
Introduction
Connecting the DC buses of frequency converters together results in energy savings
and in some cases simplifies the connection to the main supply. With common DC
the braking energy of one converter can be used for the other converters and
motors.
Unequal current distribution and different charging methods cause difficulties to
common DC systems:
• Unequal current distribution is influenced by input cables, AC or DC chokes and
input bridges’ forward characteristics. If the voltage reduction over the supply
components mentioned is not the same with all converters, more current will flow
through the converter which has a lower voltage reduction. Factors which
influence the current distribution include temperature, tolerances of components
and in DC choke cases the input cable’s cross-sectional area and length.
• Charging methods vary depending on the converter size. Because of this in some
installations, the supplies of the frame sizes R2-R4 should be disconnected when
they are connected parallel with frame sizes R5-R8.
Note: The drive compliance with the EMC Directive on low voltage networks is
specified in the appropriate Hardware Manual. However, please notice that different
common DC configurations have not been tested according to the EMC
requirements of conducted and radiated emissions.

Possible main supply connections
8
Possible main supply connections
Figure 1. Common DC connections. Cases a and b.
Figure 2. Common DC connections. Cases c, d1 and d2.
Cases b, c and d can be used when the total power taken from the main supply,
Pout.tot, is smaller than the drive power rating, Pcont.max, of the biggest converter.
+
-+ -+ -
R8 R7 R6
F8 F7 F6
M
3~
M
3~
M
3~
+
-+ -+ -
F8
R8 R8 R8
F8
M
3~
M
3~
M
3~
+
-+ -+ -
R6 R8 R7
F8
F6 F7
M
3~
M
3~
M
3~
+
-+ -+ -
R7 / R6 R7 R7 / R5
F7
M
3~
M
3~
M
3~

Possible main supply connections
9
Case a)
The most common set-up, where all converters are connected to the main supply.
When the charging circuits of the converters are different, this connection is not
always allowed. Table 1 shows when the connection cannot be used.
Case b)
Converters are identical and only one converter is connected directly to the main
supply.
Case c)
Converters are not identical and only the biggest converter is connected directly to
the main supply. The AC cables to the other converters are protected by
drive-specific fuses.
Case d1)
Converters are identical and only one converter is connected directly to the main
supply. The charging circuit of the connected converter is capable of charging the
whole DC bus.
Case d2)
Converters are not identical and only the biggest converter is connected to the main
supply. Charging circuit of the connected converter is capable of charging the whole
DC bus.
Note: If the charging circuit in case d1/d2 is not capable of charging the DC bus,
connection presented in case b/c must be used.
Note: With frame sizes R5...R8 the charging circuit in case d1/d2 might not be able
to withstand the three times larger charging energies. In this case the main supply
cable is wired to all of the input rectifiers as presented in case b/c.
Note: With ACS800-11 only connection presented in case d1/d2 is allowed.
Note: With ACS800-11 220 V units, the voltage drop over the charging resistor
during charging can generate a permanent undervoltage fault. Contact your local
ABB representative for help on designing the common DC configuration!
To determine whether it is possible to leave some converters unconnected to the
main supply see Appendix A Charging circuit capacity.

Step by step guide
10
Step by step guide
1) Select the converters and preselect the main supply connection. See Possible
main supply connections and Appendix A Charging circuit capacity.
2) Check from Table 1 that the connection is possible.
3) Check by using equation 1 that the load does not exceed the total power limit
Pout.tot of the system. See Power limit.
4) Select the fuses, cables and possible contactors for the DC side. See Fuses,
Cables and Contactors, DC bus and brake circuit.
5) Calculate the braking power and determine whether the braking cycle can be
performed and whether an internal or an external brake chopper is needed. See
Allowed braking power and need for a brake resistor.
6) If resistor braking is needed, select the internal or external brake chopper, the
resistor and the contactor. See Internal brake chopper, External brake chopper and
Contactors, DC bus and brake circuit.
7) Set up the common DC system according to the wiring instructions. See Wiring.
8) If the input terminals of frame sizes R7 and R8 are left unconnected, make sure
that the AC fans are powered separately. See Appendix B Powering the AC fans of
R7 and R8.
9) Set the common DC system related parameter values. See Start-up.