rotary encoders in electromagnetic fi elds EN 50 174-2 EN 50 178 greater than 30 mT, HEIDENHAIN recommends consulting with the main facility in Traunreut.Both the cable shielding and the metal housings of encoders and subsequent electronics have a shielding function. The housings must have the /09.01, Chapter 6.7, regarding grounding and potential compensation. When using /4.98 Chapter 5.3.1.1, regarding cables and lines, as well as same potential and be connected to the main signal ground over the machine chassis or by means of a separate potential compensating line. Potential compensating lines should have a minimum cross section of 6 mm EN 50 178 /4.98 Chapter 5.2.9.5 regarding “protective connection lines with small cross section.” Do not lay signal cables in the direct vicinity of interference sources (inductive consumers such as contacts, motors, frequency inverters, solenoids, etc.). Suffi cient decoupling from interference-signal-conducting cables can usually be achieved by an air clearance of 100 mm or, when cables are in metal ducts, by a grounded partition. A minimum spacing of 200 mm to inductors in switch-mode power supplies is required. See also Protection against electrical noise The following measures must be taken to ensure disturbance-free operation:Use only HEIDENHAIN cables.Use connectors or terminal boxes with metal housings. Do not conduct any extraneous signals. Connect the housings of the encoder, connector, terminal box and evaluation electronics through the shield of the cable. Connect the shielding in the area of the cable outlets to be as induction-free as possible (short, full-surface contact).Connect the entire shielding system with the protective ground. Prevent contact of loose connector housings with other metal surfaces. The cable shielding has the function of an equipotential bonding conductor. If compensating currents are to be expected within the entire system, a separate equipotential bonding conductor must be provided. Also see • •

Electrically Permissible Speed/Traversing Speed Noise-Free Signal Transmission

•••• Specifi cally: – ESD EN 61 000-4-2 – Electromagnetic fi elds EN 61 000-4-3 – Burst EN 61 000-4-4 – Surge EN 61 000-4-5 – Conducted disturbances EN 61 000-4-6 – Power frequency magnetic fi elds EN 61 000-4-8 – Pulse magnetic fi elds EN 61 000-4-9 Noise immunity EN 61 000-6-2: Electromagnetic compatibility/CE compliance When properly installed, and when HEIDENHAIN connecting cables and cable assemblies manufacturer are used, HEIDENHAIN encoders fulfi ll the requirements for electromagnetic compatibility according to 2004/108/EC with respect to the generic standards for: Specifi cally: – For industrial, scientifi c and medical (ISM) equipment EN 55 011 – For information technology equipment EN 55 022 The maximum permissible shaft speed or traversing speed of an encoder is derived fromthe Interference EN 61 000-6-4: Specifi cations mechanically )andthe permissible shaft speed/traversing speed (if listed in the square-wave signals, the electrically permissible shaft speed/traversing speed is limited by– the maximum permissible scanning frequency f electrically permissible shaft speed or traversing speed. For encoders with sinusoidal output signals, the electrically permissible shaft speed or traversing speed is limited by the –3dB/ –6dB cutoff frequency or the permissible input frequency of the subsequent electronics. For encoders with Transmission of measuring signals—electrical noise immunity Noise voltages arise mainly through capacitive or inductive transfer. Electrical noise can be introduced into the system over signal lines and input or output terminals. Possible sources of noise are:Strong magnetic fi elds from industrial transformers, industrial brakes and electric motors Relays, contactors and solenoid valves High-frequency equipment, pulse devices, and stray magnetic fi elds from switch-mode power supplies AC power lines and supply lines to the above devices
max of the encoderand– the minimum permissible edge separation a for the subsequent electronics. For angular or rotary encoders n
max 3 max = · 60 · 10 z For linear encoders v
–3 max = f
max · SP · 60 · 10 and: n
max : Electrically permissible speed in min
–1 v
max : Elec. permissible traversing speed in m/min f
max : Max. scanning/output frequency of encoder or input frequency of subsequent electronics in kHz z: Line count of the angle or rotary encoder per 360° SP: Signal period of the linear encoder in µm •• f
2 (Cu). ••••• • •••• Minimum distance from sources of interference

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