Guidelines For Compliance With Emc Directive - Elster A1140 User Manual

5
Communications
___________________________________________________________________________
2.3

Guidelines for Compliance with EMC Directive

The A1120/40 meter has been designed and tested for compliance with the EMC and other
applicable directives.
It is, however, the responsibility of the installer to ensure that an installed system conforms to
the directives.
In order to assist the installer the following guidelines are given:
1. Keep a.c. circuits and d.c. circuits separated by a minimum of 50mm where ever possible
2. Where a.c. and d.c. circuits cross, they must do so at right angles to each other
3. The cables for each circuit must be bunched together to minimise the loop area enclosed
4. Where the environment is electrically hostile, screened twisted pair cables may be required.
The screen must be connected to earth at one point only
5. Ancillary equipment must also be CE marked
Recommended transmission distances for RS232 and RS485 are shown
below:
The RS232 or RS485 incoming cable should always be connected to the first meter in the
multi-drop chain.
Connecting a cable to a meter in the middle of a chain is not recommended.