Required for CE-Compliance
d) Wiring Practices - Conductors of different circuits
Subject to the constraints for EMC suppression given in Sections 2.3 and Section 3 of this User’s manual, conductors of different circuits may be laid side by side, may occupy the same duct (e.g. conduit, cable trunking system), or may be in the same multicore cable, provided that the arrangement does not impair the proper functioning of the respective circuits. Where these circuits operate at different voltages, the conductors shall be either separated by suitable barriers or insulated for the highest voltage to which any conductor within the same duct can be subjected.
Circuits which are not switched off by the supply disconnecting device (circuit breaker) shall be either physically separated from other wiring or distinguished by colour (or both) so that they can be identified as being live when the supply disconnecting device is in the OFF or OPEN position.
e) Wiring Practices - Identification of conductors
For safety reasons, the colour Green or the colour Yellow shall not be used where there is a possibility of confusion with the bicolour combination GREEN-AND- YELLOW.
Colour identification using combinations of colours may be used provided there can be no confusion and that GREEN or YELLOW is not used, except in the bicolour combination GREEN- AND-YELLOW.
f) Wiring Practices - Identification of the protective conductor
The protective conductor shall be readily distinguishable by shape, location, marking or colour. When identification is by colour alone, the bicolour combination GREEN-AND-YELLOW shall be used throughout the length of the conductor. This colour identification is strictly reserved for the protective conductor.
For insulated conductors, the bicolour combination GREEN-AND-YELLOW shall be such that on any 15mm length, one of the colours covers at least 30% and not more than 70% of the surface of the conductor, the other colour covering the remainder of the surface.
Where the protective conductor can be easily identified by its shape, position or construction (e.g. braided conductor), or where the insulated conductor is not readily accessible, colour coding throughout its length is not necessary but the ends or accessible positions shall be clearly identified by the graphical symbol or by the bicolour combination GREEN-AND-YELLOW.
g) Wiring Practices - Identification of the neutral conductor
Where a circuit includes a neutral conductor identified by colour, the colour shall be LIGHT BLUE. LIGHT BLUE shall not be used for identifying any other conductor where confusion is possible.
In the absence of a neutral conductor, a LIGHT BLUE conductor may be used for other purposes except for use as a protective conductor.
Where identification by colour is used, bare conductors used as neutral conductors shall be either coloured by a LIGHT BLUE stripe, 15 mm to 100 mm wide, in each compartment or unit or at each accessible position, or coloured LIGHT BLUE throughout their length.
h) Wiring Practices - Wiring inside enclosures
Panel conductors shall be supported where necessary to keep them in place. Non-metallic channels or conduits shall be permitted only when made with a flame-retardant insulating material. Where possible earthed shielded metal cable ducting should be used to minimise EMC noise coupling.
It is recommended that electrical equipment mounted inside the enclosures be designed and constructed in such a way as to permit modification of the wiring from the front of the enclosure. Where this is not possible and control devices are connected from the rear of the enclosure, access doors or swing-out panels shall be provided.
Connections to devices mounted on doors or to other movable parts shall be made using flexible conductors in accordance with European standard EN 60204-1, to allow for the frequent movement of the part. The conductors shall be anchored to the fixed part and the movable part independently of the electrical connections.
Conductors and cables that do not run in ducts shall be adequately supported.
Terminal blocks or attachment plug/socket combinations shall be used for control wiring that extends beyond the enclosure.
Power cables and cables of measuring circuits may be directly connected to the terminals of the devices for which the connections were intended.
i) Wiring Practices - Wiring outside enclosures
The means of introduction of cables or ducts with their individual glands, bushings, etc., into an enclosure shall ensure that the degree of protection is not reduced.
Conductors and their connections external to the electrical equipment IP54 enclosures shall be installed in suitable ducts (i.e. conduit or cable trunking systems) as described in Section 2.3.4, except for suitably protected cables, which may be installed without enclosing ducts and with or without the use of open cable trays or cable support means.
Fittings used with ducts or multi-conductor cable shall be suitable for the physical environment.
Flexible conduit or flexible multi-conductor cable shall be used where it is necessary to employ flexible connections to pendant push-button stations. The weight of pendant stations shall be supported by means other than the flexible conduit or the flexible multi-conductor cable, except where the conduit or cable is specifically designed for that purpose.
Flexible conduit or flexible multi-conductor cable shall be used for connections involving small or infrequent movements. They shall also be permitted to complete the connection to normally stationary motors, to position switches, and to other externally mounted devices.
Connections to frequently moving parts shall be made with conductors suitable for flexing service in accordance with European standard EN 60204-1. Flexible cable and flexible conduit shall be so installed as to avoid excessive flexing and straining particularly at the fittings.
Cables subject to movement shall be supported in such a way that there is no mechanical strain on the connection points nor any sharp bending. The loop shall have sufficient length to provide for a bending radius of the cable of at least ten times its outside diameter.
Where cables subject to movement are close to moving parts, precautions shall be taken so that a space of at least 25mm shall be maintained between the moving parts and the cables. Where this distance is not practicable, fixed barriers shall be provided between the cables and the moving parts.
The cable sheath shall be resistant to the normal wear which can be expected from movement, and to the effects of atmospheric contaminants (e.g. oil, water, coolants, dust).
Where flexible conduit is adjacent to moving parts, the construction and supporting means shall prevent damage to the flexible conduit or cable under all conditions of operation.
Flexible metal conduit shall not be used for rapid or frequent movements, except when specifically designed for that purpose.
j) Wiring Practices - Ducts, connection and junction boxes
All sharp edges, flash, burrs, rough surfaces, or threads, with which the insulation of the conductors may come in contact, shall be removed from ducts and fittings. Where necessary, additional protection consisting of a flame-retardant, oil-resistant insulating material shall be provided to protect conductor insulation.
Ducts and cable trays shall be rigidly supported and positioned at a sufficient distance from the moving parts and in such a manner so as to minimise the possibility of damage or wear.
Cable trunking systems external to enclosures shall be rigidly supported and clear of all moving or contaminating portions of the machine or equipment into which they are installed.
2.3.4 EMC requirements for cables
Avoid close parallel routing of signal cables and power cables. Always use the minimum length of cable necessary and install all cables in a fixed routing.
Data signal cables, motor power and resolver/signal cables, regen resistor cables and power input cables shall have segregated routings. Where cable routings must intersect, it is recommended that they intersect at an angle of 90 degrees, to minimise EMC noise coupling.
Where signal and power cables must run in parallel it is recommended that these cables are separated by at least 20 cm.
Where possible cables shall be routed in earthed shielded cable ducting, to minimise electromagnetic noise coupling.
Use shielded cable to connect the external regen resistor (if installed) to the T200 power supply. The length of this cable shall be as short as possible. The shields of these voltage supply cables shall be earthed to Chassis Earth using the optional EMC kit or the panel earth bar. Alternatively, if the cable is required to pass through an enclosure panel earthed to Chassis Earth, the shield may be earthed to the panel by use of a 360 degree metal cable gland. (Refer to Section 2.3 and Section 3.13 for safety and other relevant installation requirements for Regen resistors).
Cables supplying external d.c. supply voltages to the T200 Servo-drive (For example, the 24 Vd.c. supply) must be as short as possible. The supply wires shall be twisted together or alternatively shielded cable shall be used.
Cables connecting the 325 V d.c. bus from the T200 Servo-drives must be as short as possible. The supply wires shall be twisted together.
Motor power cables must be shielded with the cable shield securely connected to Chassis Earth at both ends of the cable.
At the T200 end of the cable the shield shall be earthed to Chassis Earth using the optional EMC kit or the panel earth bar.
Motor resolver/signal cables must be shielded with the cable shield securely connected to Chassis Earth at both ends of the cable.
Signal cables must be shielded with the cable shield securely connected to make a good HF earth bond to Chassis Earth at both ends of the cable.