User Manual

AS4000 Subscriber Terminal
Installation and Commissioning GSI 002
605-0000-436
Issue 1.5 Date: 18th October 1999
Page 4 of 6
The ST equipment is powered from the AC mains supply available at the
customer’s premises. This Power supply consists of an AC/DC converter that
converts the customers 230/110V AC mains supply to a 30 Volt DC supply for
the CRU, and a Junction Box that facilitates the connection of the DC supply to
the Drop Cable. The Junction Box also contains test access and connection points
to connect NTU’s to the Drop Cable.
2) AC Power Supply Units (Type 2 and 4)
The Type 2 and 4 PSUs are available for the ST-V2 The PSU receives the mains
supply and generates a 24V DC level to power the external CRU. In addition, the
PSU contains an internal 24V lead-acid battery which is trickle-charged and
which provides a back-up supply for approximately three hours. The battery has
an operational life of five years.
The PSU generates alarms as follows:
a) PSU tamper alarm, in the event the lid is removed
b) Mains supply failure
c) Low battery voltage alarm
d) Failure of the AC PSU
and terminates the following test signals sent from Sitespan /Element manager to
simulate:
a) A hazardous voltage on VF line
b) An earth leakage condition
c) Detect the presence of NTU(s) and Customer Equipment
d) Mains supply failure to the AC PSU
Visual indication of mains failure is by an LED on the side of the unit. Also
within the AC PSU are an “install switch” (S2) and two LED’s (D8 and D9)
which are used during the initial installation of the ST equipment as part of the
frequency and code setting procedure.
3) AC Power Supply Unit (Type 4A)
This Power supply consists of an AC/DC converter that converts the customers
230/110V AC mains supply to a 40 Volt DC supply for the CRU, The PSU also
contains test access and connection points to connect NTU’s and the Drop Cable.
It is primarily designed for the ST- D128 but may be used for ST-V2 and ST-I1 if
battery backup is not required.
6. Drop Cables
6.01 The drop cable connects the PSU/Junction Box to the CRU via an environmentally
protected 12 pin connector which plugs into the rear of the CRU. It consists of:
• 2 wires for DC power for the CRU
• 4 wires for transmit and receive
• 2 wires for alarm communications between the units