The following technical note relates to the list products (G13801N-A-Raytel, G13802NU, G13803N-B-Raytel, AR-716E-RAY & EAR-727HB-RAY).

However, for your general information the following characteristic may apply to other power supplies of the switch mode design.

Please note that although the earth terminal on a 240V switch mode power supply should always be connected to the earth terminal in any metal enclosure in which it may be mounted, and thereby to a general earth connection, it is still possible to sustain a mild electric shock in the region of 95v at 170µA from the 0V terminal of the power supply if it is not also connected to earth. Although this would not normally be regarded as more than uncomfortable, it could be extremely dangerous if it was sustained by an operative either working up a ladder or with a heart condition. We recommend, therefore, that unless there are good technical reasons for not doing so the 0V terminal should always be connected to earth.

This is also important for technical reasons in order to ensure stability throughout any system or network utilizing this type of power supply.

It has been drawn to our attention by some of our customers, that high resistance cable with alternative metal content (such as Steel, Aluminium etc.) is widely available. These ‘low cost cables’ have dramatically higher cable resistance per 100m than conventional copper wire cables, and therefore if used on an installation it could dramatically affect the systems operation and functionality.
All cables specified directly or in-directly on any wiring diagram issued by Raytel are expected to be made of solid copper wire.
Technical Department