Electromagnetic Compatibility, EMC

Electromagnetic Disturbances of Signals and Devices

This product meets the EMC requirements in accordance with the standard IEC 61131-2, provided that the EMC measures described in this manual are complied with during installation.

WARNING
	SIGNAL AND EQUIPMENT INTERFERENCE Install the wiring in accordance with the EMC requirements described in the present document. Verify compliance with the EMC requirements described in the present document. Verify compliance with all EMC regulations and requirements applicable in the country in which the product is to be operated and with all EMC regulations and requirements applicable at the installation site. Failure to follow these instructions can result in death, serious injury, or equipment damage.

WARNING

SIGNAL AND EQUIPMENT INTERFERENCE

Install the wiring in accordance with the EMC requirements described in the present document.
Verify compliance with the EMC requirements described in the present document.
Verify compliance with all EMC regulations and requirements applicable in the country in which the product is to be operated and with all EMC regulations and requirements applicable at the installation site.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

WARNING
	ELECTROMAGNETIC DISTURBANCES OF SIGNALS AND DEVICES Use proper EMC shielding techniques to help prevent unintended device operation in accordance with the standard IEC 61131-2. Failure to follow these instructions can result in death, serious injury, or equipment damage.

These types of devices are not intended to be used on a low-voltage public network which supplies domestic premises. Radio frequency interference is expected if used in such a network.

WARNING
	RADIO INTERFERENCE Do not use these products in domestic electrical networks. Failure to follow these instructions can result in death, serious injury, or equipment damage.

Layout Control Cabinet (Enclosure)

The prerequisite for compliance with the specified limit values is an EMC compatible layout. Depending on the application, the following measures can improve the EMC-dependent values:

EMC measures	Objective
Use galvanized or chromium-plated sub plates, bond metallic parts across large surface areas, remove paint layer from contact surfaces.	Good conductivity by surface area contact.
Ground control cabinet (enclosure), door, and sub plates by using grounding strips or grounding cables with a cross-section of 10 mm² (AWG 6).	Reduce emission.
Supplement switch devices such as contactors, relays, or magnetic valves with interference suppression combinations or spark suppressor elements (for example, diodes, varistors, RC elements).	Reduces mutual interference.
Fit power and control components separately.	Reduces mutual interference.

Shielded Cables

EMC measures	Objective
Connect large surface areas of cable shields, use cable clamps and ground straps.	Reduce emission.
Ground shields of digital signal wires at both ends by connecting them to a large surface area or via conductive connector housings.	Reduce interference action on signal cables, reduce emissions.
Ground shield of analog signal cables directly on the device (signal input), insulate the shield at the other cable end or ground the same through a capacitor, such as 10 nF.	Reduce grounding loops by low frequency interferences.

Cable Installation

EMC measures	Objective
Do not route fieldbus cables and signal wires in a single cable duct together with lines with DC and AC voltages of more than 60 V. (Fieldbus cables, signal lines, and analog lines may be in the same cable duct). Electromagnetic immunity will improve by routing cables in separated cable ducts with a distance of at least 20 cm (7.84 in).	Reduces mutual interference.
Keep cables as short as possible. Do not install unnecessary cable loops, use short cables from the central grounding point in the control cabinet to the external ground connection.	Reduces capacitive and inductive interference.
Use equipotential bonding conductors (stranded wire of equal potential at all grounding locations connected to an equipotential grounding plane) in the following cases: wide-area installations, different voltage supplies, and installation across several buildings.	Reduces current in the cable shield, reduces emissions.
Use stranded wire potential equalization conductor.	Discharging of high frequency interference currents.
If motor and machine are not conductively connected, for example by an insulated flange or a connection without surface contact, you must ground the motor with a ground strap or a ground wire. The conductor cross section must be at least 10 mm² (AWG 6).	Reduces emissions, increases immunity.
Use twisted pair for 24 Vdc signals.	Reduce interference action on signal cables, reduce emissions.

Power Supply

EMC measures	Objective
Operate product on mains with grounded neutral point.	Enables effectiveness of mains filter.
Use surge arrester if there is a risk of overvoltage.	Reduces the risk of damage caused by overvoltage.

Motor and Encoder Cables

From an EMC perspective, motor supply cables and encoder cables are particularly important. Only use pre-configured cables, or cables with the prescribed properties, and comply with the following EMC measures.

EMC measures

Objective

Do not install switching elements in motor cables or encoder cables.

Reduces interference.

Route motor cable with a distance of at least 20 cm (7.84 in) to the signal cables or insert shield plates between the motor supply cable and the signal cable.

Reduces mutual interference.

For wiring that approaches the maximum cable distance specification (75 m/ 246.06 ft.), use equipotential bonding connection cables.

Reduce current on cable shield.

Route motor supply cables and encoder cables without any separation point⁽¹⁾.

Reduces emission.

(1)	If a cable must be cut through for installation purposes, the cables must be connected at the point of separation by using screen connections and metal housing.

Additional Measures for Improving the EMC

Depending on the respective application, the following measures may lead to an EMC compatible layout:

EMC measures	Objective
Upstream connection of mains line reactor (choke)	Reduction of the harmonic network oscillations, extension of the service life of the product.
Upstream connection of external mains filters	Improvement of the EMC limit values.
Special EMC-appropriate layout, for example, within an enclosed control cabinet complete with 15 dB attenuation of the interferences emitted	Improvement of the EMC limit values.