1-10
Wire/Cable Types
Input Power Cables
In general, the selection of cable for AC input power to a drive has no
special requirements. Some installations may suggest shielded cable to
prevent coupling of noise onto the cable (see
) and in some cases,
shielded cable may be required to meet noise standards such as CE for
Europe, C-Tick for Australia / New Zealand, and others. This may be
especially true if an input filter is required to meet a standard. Each
individual drive user manual will show the requirements for meeting these
types of standards. Additionally, individual industries may have required
standards due to environment or experience.
For AC variable frequency drive applications that must satisfy EMC
standards for CE, C-Tick, FCC or other, Rockwell Automation may
recommend that the same type of shielded cable specified for the AC motors
be used between the drive and transformer. Check the individual user
manuals or system schematic note sheets for specific additional
requirements in these situations.
Motor Cables
The majority of recommendations regarding drive cable address issues
caused by the nature of the drive output. A PWM drive creates AC motor
current by sending DC voltage pulses to the motor in a specific pattern.
These pulses affect the wire insulation and can be a source of electrical
noise. The rise time, amplitude, and frequency of these pulses must be
considered when choosing a wire / cable type. The choice of cable must
consider:
1.
The effects of the drive output once the cable is installed
2.
The need for the cable to contain noise caused by the drive output
3.
The amount of cable charging current available from the drive
4.
Possible voltage drop (and subsequent loss of torque) for long wire runs
Keep the motor cable lengths within the limits set by the drive's user
manual. Various issues, including cable charging current and reflected wave
voltage stress may exist. If the cable restriction is listed because of
excessive coupling current, apply the methods to calculate total cable
length, as shown in
. If the restriction is due to
voltage reflection and motor protection, tabular data is available. Refer to
for exact distances allowed.
Содержание Allen-Bradley 1305-AA02A
Страница 1: ...Installation Instructions Wiring and Grounding Guidelines for Pulse Width Modulated PWM AC Drives ...
Страница 4: ...ii Summary of Changes Notes ...
Страница 40: ...2 18 Power Distribution Notes ...
Страница 48: ...3 8 Grounding Notes ...
Страница 68: ...4 20 Practices Notes ...
Страница 78: ...6 8 Electromagnetic Interference Notes ...
Страница 94: ...Glossary 4 UL Underwriters Laboratories ...
Страница 100: ...Index 6 ...
Страница 101: ......