User guide

186 Rockwell Automation Publication 23C-IN001B-EN-P - June 2013
Chapter 4 Electrical Installation
Observe these guidelines when installing an isolation transformer:
• A power disconnecting device must be installed between the power line
and the primary of the transformer.
• If the user-installed power disconnecting device is a circuit breaker, the
circuit breaker trip rating must be coordinated with the in-rush current (10
to 12 times full load current) of the transformer.
• Do not use an input isolation transformer rated more than 1000 kVA for
480 V AC (500 kVA for 208V AC) with less than 5% impedance directly
ahead of the drive without additional impedance between the drive and
the transformer.
Tab le 15
shows recommended inductance and line reactor ratings.
Table 15 - AC Line Reactors
Installing Fuses for Branch Circuit Protection
If they were not installed as a factory option, install the required branch circuit
protection fuses according to the applicable local, national, and international
codes (such as NEC/CEC). The fuses must be installed in the line before the
drive input terminals.
Drive (Hp) Line Reactor Inductance (±10%)
2…3 6.5 mH
53.0 mH
7.5 2.5 mH
10 1.5 mH
15 1.2 mH
20 0.8 mH
25 0.8 mH
30 0.7 mH
40 0.5 mH
50 to 60 0.4 mH
75 0.3 mH
100 0.2 mH
125 0.15 mH
150 0.11 mH
ATTENTION: Most codes require that upstream branch protection be provided
to protect input power wiring. Failure to observe this precaution could result
in severe bodily injury or loss of life.