- Means of easy identification of the terminal connections should be provided on the main distribution frame (MDF).
- The use of over voltage protection is possible on all incoming subscriber pairs but not mandatory in case of fully buried subscriber cabling. The MDF should accept cable with a conductor diameter of 0,4 to 0,6 mm..
- Precautions should be taken to ensure that metal parts on which voltages higher than 60 V DC or 42 V AC can occur are not readily accessible.
- The MDF should be equipped with a copper ground bus bar of adequate cross-section area.
- All frames must have a smooth finish, are easy to clean and have no projections or sharp edges.
- MDF should provide the possibility for separating of the line side, for parallel measurement and for connection of an auxiliary measuring equipment to the line- and equipment-side.
- MDF should have high reliability, especially the parts subjected to mechanical actions.
- All cabling should be clearly labeled to enable easy identification.
- It may be preferred that Connections are made with a technique which does not require skills or extended training.
Important Note: The subscriber interfaces of Telesis systems have over-voltage protection, conforming to ITU-T K.20/K.21 recommendations. Additional primary protection devices to those residing in the main distribution frame may also be employed for further protection. Telesis A.S. recommends double sided, line side surge-protected, and good quality MDF.
