Inter-Tel AXXESS Manual page 223

C. CONNECTING BASIC RATE INTERFACE (BRI) TRUNKS TO THE MDF
Connect a Power Supply to the BRS
7.26 Each of the eight BRS ports can be configured to receive line power from the BRS card.
If the device connected to a BRS port uses power from the BRS, the jumper for its port must
be set over the bottom four pins. In the default position, the jumper is set over the top four
pins, which prevents the port from using power from the BRS.
NOTE:
in the default position, the jumper connects pins 5 to 6 and 7 to 8. See
133 for jumper positioning.
7.27 Most TE devices use external power sources and do not require power from the BRS
card. However, the installer should check the power connection information for the terminating
device to determine how to connect it to the BRS. External power can be made available to the
devices on the card by connecting an Inter-Tel -48VDC power supply to the card in one of the
following ways:
•
Connect an Inter-Tel adapter cable (part number 813.1740, included with the card) with
the Inter-Tel -48VDC power supply – part number 550.0114 [PS2743 in Europe] to
connector J7 on the BRS card. See
•
Connect the external power supply to the BRS card at the MDF, using pins 25 and 50
on the Amphenol-type connector. See
through 3-43.
7.28 The BRS limits the amount of current available to each port by using a PTC resettable
fuse type device for each port. The PTC allows at least 60 mA of current per port.
Connect Devices to the BRS Cards
7.29 The installer must check the connection information for the terminating device to deter-
mine how to connect it to the BRS.
7.30 There are several ways in which a device can receive power:
•
Line power: Power can be provided over the device cabling in two ways:
—
—
Connecting Basic Rate Interface (BRI) Trunks to the MDF
INTER-TEL
The jumper should have an orientation that connects the pins horizontally. For example,
From the BRS port: One power supply, connected to the BRS, can provide
power to all ports on the card that have their jumpers set on the bottom pins. You
can run two-pair or three-pair wire to the devices. (See
for a wiring diagram.)
Using two-pair wire, the power from the BRS is provided to the device over
the transmit and receive pairs.
Using three-pair wire, the power is provided over the third pair.
From an external supply at the MDF: You can punch down the connection
between an external power supply and the device at the MDF. In this case, you
would use three-pair wire. Each device would have an individual power supply
connected to its third pair, as shown in the following diagram. The power supply
is not connected to the BRS.
® ®
AXXESS MANUAL VERSION 11.0 – May 2008
page 3-133 for an illustration.
Figures 3-4 through
Installation
Figure 3-63 on page 3-
Figures 3-6 on pages 3-40
Figure 3-4 on page 3-40
Page 3-37
3