SIGMATEK 074.00660, Power Installation Manual

Page: 50 / 98

50
Sigmatek FDD Sizes 7 to 9 Power Installation Guide
4.1.1 Ground connections
The drive must be connected to the system ground of the AC supply. The ground wiring must
conform to local regulations and codes of practice.
On size 9E, the supply and motor ground connections are made using the M10 studs located by the
supply and motor connection terminals. Refer to Figure 4-3.
Table 4-1 Protective ground cable ratings
4.2 AC Supply requirements
AC supply voltage:
400 V drive: 380 V to 480 V ±10 %
Number of phases: 3
Maximum supply imbalance: 2 % negative phase sequence (equivalent to 3 % voltage imbalance
between phases).
Frequency range: 45 to 66 Hz
For UL compliance only, the maximum supply symmetrical fault current must be limited to 100 kA
Table 4-2 Supply fault current used to calculate maximum input currents
Electrochemical corrosion of grounding terminals
Ensure that grounding terminals are protected against corrosion i.e. as could be caused
by condensation.
The ground loop impedance must conform to the requirements of local safety regulations.
The drive must be grounded by a connection capable of carrying the prospective fault
current until the protective device (fuse, etc.) disconnects the AC supply.
The ground connections must be inspected and tested at appropriate intervals.
Input phase conductor size Minimum ground conductor size
≤ 10 mm
2
Either 10 mm
2
or two conductors of the same cross-sectional area as the input
phase conductor
> 10 mm
2
and ≤ 16 mm
2
The same cross-sectional area as the input phase conductor
> 16 mm
2
and ≤ 35 mm
2
16 mm
2
> 35 mm
2
Half of the cross-sectional area of the input phase conductor
Model Symmetrical fault level (kA)
All 100
WARNING
WARNING