Fuse Sizing; Hf Bonding Your System - Allen-Bradley Ultra1500 2092-DA1 User Manual

Input Power Type Short Circuit Current Rating with No Fuse
Drive Models:
Main Power
2092-DA-xxx and
Control Power

HF Bonding Your System

Fuse Sizing

In the United States, the National Electric Code (NEC) specifies that fuses
must be selected based on the motor full load amperage (FLA). The typical
fuse size should be 300% of the motor FLA for non-time delay fuses (and
time-delay class CC fuses) or 175% of motor FLA for time delay fuses. If these
ratings are not high enough for starting currents, the NEC allows non-time
delay fuses (and time-delay class CC fuses) to be sized up to 400% of the
motor FLA and time-delay fuses to be sized up to 225% of the motor FLA.
In most cases, fuses selected to match the drive input current rating will meet
the NEC requirements and provide the full drive capabilities. Dual element,
time delay (slow acting) fuses should be used to avoid nuisance trips during the
inrush current of power initialization. Refer to the section Ultra1500 Power
Specifications in Appendix A for fuse recommendations, as well as input current
and inrush current specifications.
The Ultra1500 utilizes solid state motor short circuit protection rated as shown
in the table below.
Restrictions:
Suitable for use on a circuit capable of delivering
not more than 5000 rms symmetrical amperes,
240V maximum.
Wiring to the control power terminals (L1C and L2C) of the drive should be
2
2.5 mm (14 AWG) minimum and fusing for the control power should be
selected to properly protect the wire. For example, if 60° C (140° F) wire is
used, the fuse should not exceed 8A. If 75° C (167° F) wire is used, the fuse
should not exceed 13A. Refer to Fuse and Contactor Specifications in Appendix A
for fuse recommendations.
Bonding is the practice of connecting metal chassis, assemblies, frames, shields
and enclosures to reduce the effects of electromagnetic interference (EMI).
For more information on the concept of high-frequency (HF) bonding, the
ground plane principle, and electrical noise reduction, refer to the System Design
for Control of Electrical Noise Reference Manual (publication
GMC-RM001x-EN-P).
Installing Your Ultra1500
Short Circuit Current Rating with Fuse
Restrictions:
Suitable for use on a circuit capable of delivering
not more than 200,000 rms symmetrical
amperes, 240V maximum, when protected by
high interrupting capacity, current limiting fuses
meeting UL 198C (Class CC, G, J, L, R, T).
Publication 2092-UM001D-EN-P — July 2005
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