HEIDENHAIN TNC 370D - Manual (Page 9)

3–6 TNC 370 D Mounting and Electrical Installation July 02
3 Mounting and Electrical Installation
3.1 Electrical Noise Immunity
Location for Use
This device corresponds to Class A according to EN 55022 and is intended primarily for operation in
industrially zoned areas.
Remember that the vulnerability of electronic equipment to noise increases with faster signal
processing and higher sensitivity. Protect your equipment by observing the following rules and
recommendations.
Noise voltages are mainly produced and transmitted by capacitive and inductive coupling.
Electrical noise can be picked up by the inputs and outputs to the equipment, and the cabling.
Likely sources of interference are:
· Strong magnetic fields from transformers and electric motors
· Relays, contactors and solenoid valves
· High-frequency equipment, pulse equipment and stray magnetic fields from switch-mode
power supplies
· Mains leads and leads to the above equipment
Electrical interference can be avoided by:
· A minimum distance of 20 cm between the logic unit (and its leads) and interfering equipment.
· A minimum distance of 10 cm between the logic unit (and its leads) and cables carrying
interference signals. (Where signal cables and cables that carry interference signals are laid
together in metallic ducting, adequate decoupling can be achieved by using a grounded
separation shield.)
· Shielding according to IEC 742 EN 50 178
· Potential compensating lines — Æ ³ 6 mm²/10 mm² (see Grounding Plan)
· Use of original HEIDENHAIN cables, connectors and couplings.