ABB AM811F ACS800F programmable controller
Note 1: The supply transformer minimum power in kVA is calculated with a zk value of 6% andfrequency 50 Hz.
Note 2: The table is not intended for transformer selection - that must be done separately.
The following parameters can effect on the correct operation of the protection:
• cable length, i.e. the longer the cable the weaker the fuse protection, as the long cable limits the
fault current
• cable size, i.e. the smaller the cable cross-section the weaker the fuse protection, as the small cable
size limits the fault current
• transformer size, i.e the smaller the transformer the weaker the fuse protection, as the small
transformer limits the fault current
• transformer impedance, i.e. the higher the zk the weaker the fuse protection as high impedance
limits the fault current.
The protection can be improved by installing a larger supply transformer and/or bigger cables, and in
most cases by selecting aR fuses instead of gG fuses. Selection of smaller fuses improves the
protection, but may also affect the fuse life time and lead to unnecessary operation of the fuses.
In case of any uncertainty regarding the drive protection, please contact your local ABB.

Cable types
The table below gives copper and aluminium cable types for different load currents.
Cable sizing is based on max. 9 cables laid on a cable ladder side by side, ambient
temperature 30 °C, PVC insulation, surface temperature 70 °C (EN/IEC 60204-1 and
IEC 60364-5-52:2001). For other conditions, size the cables according to local
safety regulations, appropriate input voltage and the load current of the drive.
Cable entries
Mains, motor and brake resistor cable terminal sizes (per phase), maximum
accepted cable and tightening torques are given below.
Dimensions, weights and noise
H height
W1 width of the basic unit with PE terminal (bookshelf)
W2 width with the cable connection terminal plates on the left side only (bookshelf)
(R7: width with the cable connection terminal plates on both sides is 579 mm)
(R8: width with the cable connection terminal plates on both sides is 776 mm)
D depth without fastening brackets
(R7 bookshelf: depth with fastening brackets is 516 mm)
(R8 bookshelf: depth with fastening brackets is 571 mm)
W3 width of the basic unit with PE terminal/busbar (flat)
W4 width with the cable connection terminal plates (flat)