Installing fuses for branch circuit protection – Rockwell Automation 23C PowerFlex 400 AC Drive Packages for Fan & Pump Apps User Manual

Page 186

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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.

Table 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

5

3.0 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.

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