REXROTH RD 500 RD42, Руководство по эксплуатации

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RD 500 RD42 Electrical installation
3-1
DOK-RD500*-RD42*******-IB03-EN-P
3 Electrical installation
3.1 EMC-correct design of drives
The following 10 rules are the basic guidelines for EMC-correct design of
drive systems. Details are provided in separate instructions.
Rules 1 to 7 are generally valid. Rules 8 to 10 are especially important to
limit noise emission.
Rule 1 All of the metal parts and components of the cabinet must be connected
to one another through the largest possible surface area. (Not paint on
paint!) If necessary, use contact or serrated washers. The cabinet door
should be connected to the cabinet itself through grounding strips which
should be kept as short as possible.
Rule 2 Signal, line supply and motor cables and power cables should be routed
separately from one another (avoid having any mutual coupling lengths of
cable!). Minimum clearance: 20 cm. Provide separating sheet metal
panels between power and signal cables. These panels should be
grounded at several locations along their length.
Rule 3 Contactors, relays, solenoid valves, electromechanical operating hour
counters etc. in the cabinet must be provided with noise suppression
devices. These can include, e.g. RC elements, diodes, varistors. These
devices must be connected directly to the coil.
Rule 4 Non-shielded cables belonging to the same circuit (outgoing and incoming
conductors) should be twisted and the surface area between the outgoing
and incoming conductors should be kept as small as possible. Ground the
cores which are not used at both ends.
Rule 5 Noise which is coupled-in is generally reduced if cables are routed close
to grounded sheet metal panels. This is the reason that wiring shouldn’t
be freely routed in the cabinet, but should be routed close to the cabinet
housing or to mounting panels. This is also true for cables which are
presently not being used.
Rule 6 Tachometers, encoders or resolvers must be connected using a shielded
cable. The shield should be connected to the tachometer, encoder or
resolver and to the AC drive converter through the largest possible
surface area. The shield may not be interrupted, e.g. by using
intermediate terminals. For encoders and resolvers, pre-assembled
cables with multiple shielding should be used.
Rule 7 The shields of signal cables must be connected at both ends to ground
(sender and receiver) through the largest possible surface area. If there is
poor potential bonding between the shield connections, to reduce the
current flowing through the shield, an additional bonding conductor,
minimum 10 mm² cross-section should be routed parallel to the shield.
The shield can be connected at several locations with ground (=cabinet
housing). The shields may also be grounded at several locations outside
the cabinet. Avoid using foil-type shields. Their shielding effect is a
minimum of a factor of 5 less than braided shields.
If the potential bonding is poor, analog signal cables may only be
grounded at one end at the AC converter, in order to eliminate low-
frequency noise (50 Hz) on the shield.
Rule 8 A radio interference suppression filter must always be located close to the
noise source. The filter must be connected flush with the cabinet housing,
mounting panel etc. The most favorable solution is a bare metal mounting
plate (e.g. manufactured out of stainless steel, galvanized steel), as in this
case, the complete mounting surface establishes the electrical contact.
Input and output cables to and from the radio interference suppression
filter must be routed separately from one another.