S e c t i o n 4 - I n s t a l l a t i o n
61
The BBU is housed in a similar plastic case to the telephone system and is wall mounted.
It is designed to operate with two 12V, 1.2 Ah sealed lead acid batteries of maximum dimensions 97
mm x 48.5mm x 57mm. The batteries are not supplied with the battery back up unit.
This unit provides the telephone system with a 24 volt dc feed and a 75V
RMS,
25Hz sine wave ringing
supply.
The unit will allow the telephone system to continue to operate for at least 1 hour and possibly up to
3 hours depending on how many telephones are connected and on how much they ring. System
software in the telephone system controls the ringing supply to maximise back up time.
Figure 4-8 BBU to telephone system connection diagram
Battery specifications
Measurement
Required
Height:
57mm
Width:
97 mm
Depth:
48.5 mm
Electrical spec:
12V 1.2Ah
Recommended source:
Yuasa A512/1.2S
Installation of battery back up unit
1. First disconnect the telephone system from the mains power outlet and ensure that the battery
back up unit is NOT connected to the 220-240 volt supply.
2. Ensure the 4-pin socket with the red, blue, white and black leads are connected to plug J4 on
the BBU.
3. Check if the optional 25Hz ringer card is fitted, see Figure 4-6 on page 57 for location. If fitted
remove from socket SK27 and from the transformer leads. This is not required with a BBU
unit.
4. Remove the cord bushing/grommet, which secures the mains cable to the back of the
telephone system case and remove the mains connector from the plug SK41.
Important!
PABX power
cable grommet
fits here
System Power
cable socket re-
connects here
+
-
Kickstart contacts
Green LED –
Mains power ok
Battery connector
+
-
+
-
Batteries
Black
SK27
BBU
SK22
BBU cable entry grommet
Connect white 3
wire connector
to plug
1 2 3 4
Connect 2
pin socket
with single
wire to pin 2
Telephone System
Battery Back-up Unit
Blue
Red LED –
System using
Battery power
Red
