Technical information
You may connect it –
•To direct exchange lines.
•To extensions with new plug and socket arrangements provided with these direct exchange lines.
•To compatible switchboards.
You may NOT connect it -
To shared (party) lines.
The connection to the telecommunication system must be unplugged before the earth is disconnected. The connection to the telecommunication system must not be hardwired.
This apparatus may be used on telecommunications systems employing loop disconnect or MF signalling.
How many phones can you have Your exchange line provides only a small current to make your BF900 ring. Although you may have any number of sockets it is important to limit the number of telephones and other items of apparatus connected to the line by these sockets. This ensures that each telephone will receive enough current to ring.
Every telephone or item of apparatus has a Ringer Equivalence Number (REN).
In most cases a standard line should provide enough current for two or more telephones or items of apparatus, if the REN’s add up to no more than 4.
BF900 has a REN of 1. Any telephone provided by BT may be assumed to have a REN of 1 unless otherwise stated on the base. Even where the number of telephones has been limited, there is no guarantee that the different types of telephone on the same line will ring.
The provided handset must only be connected to the socket on the side of the machine.
Another approved handset may be connected but the apparatus has been calibrated and approved for the provided handset.
The voltage drop introduced by the apparatus between the PSTN and a series connected telephone at a current of 40mA is 1.7 Volts. Consequently, no additional series equipment may be connected.
The introduction of this voltage drop may occasionally cause difficulties in making calls from the series connected telephone or problems in telephone conversation being experienced by both parties to the call. In the unlikely event of any such problems occurring, the user should contact the supplier or maintainer of the apparatus.
While operation may be possible initially, changes to or modernisation of the network, taking place in the normal course of events, may result in the apparatus being connected to a network service with which it is not designed to be compatible. Failure of the apparatus to work under these circumstances may not be the responsibility of the network operator.
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