Parker HPD2N, Руководство пользователя, Страница: 14 / 125

Parker Hannifin S.p.A. - S.B.C. Division HPD N User’s Manual
11
Avoid:
- routing noise emitting cables parallel to “clean” cables
- parallel cables, especially in the vicinity of the filter (ensure physical separation)
- cable loops (keep cables as short as possible and close to the common potential).
Additional measures
- With the exception of mains cables to the filter, all power and control wiring must be
shielded and, wherever possible, kept segregated (minimum distance 20 cm). If control and
power cables must cross, the intersection must be at a right angle.
- Shielded cables must be installed on a copper bar by means of a high conductivity wire
clamp. The area of contact must be as large as possible and the shield must be unbroken. In
general the shield should be connected at each extremity. In certain circumstances, however,
control cable shields may be connected only at one end to eliminate mains hum that could
interfere with the control signal. Decide case by case as numerous factors must be considered.
Adopt the following general approach: if the shield is solely for shielding, connect at both
ends. If current flowing in the shield interferes with the shielded signals, connect at one end
only.
- The incoming cable must be connected to an earth terminal by means of a screw to ensure
proper contact between shield and earth.
- RF interference suppression filters must be installed as close as possible to the drive and
must have a large area of contact with the power panel or the baseplate. Remove all paint. The
filter earth terminal must be connected to the earth bar along the shortest possible route.
- As far as possible keep the power side (drive) and control side (PLC or NC) physically
separated by separating the metal mounting plates. Do not route any cables through the
mounting plates.
Protective measures for drives with > 3.5mA dispersion current per phase
Interference currents dispersed through the earth system may be considerable in certain
conditions. Therefore, make sure all suppression filters are properly earthed before they are
connected. Cable sizes must be in line with the requirements of safety standards.
If a suppression filter is permanently connected and current dispersion during normal
operation is greater than 3.5mA (which would be expected with most drives) adopt one of the
following measures additionally:
a) Increase shield size to at least 10 mm².
b) Install a detection system to monitor the shield and automatically disconnect the drive in
the presence of faults.
c) Install a second conductor in parallel (electrically) with the shield using separate
terminals.