Intercall 600 - Replacing an existing System - using the existing wiring

Intercall 600/700 Installation & Operation Guide Issue 4.27 Page 19 of 78
Replacing an existing System – using the existing wiring.
The INTERCALL system is ideally suited for the replacement of existing hard wired nursecall system, using the
existing cabling but please note the following considerations.
• Study and make notes about the existing system.
The most common problems occur when the old system is removed before the wiring is understood. We need to
identify two cores common to all parts of the system which are usually the supply lines. Look for legends on the printed
circuit boards (0v, GND, +12 + etc)
• Remove all parts of the old system from the wiring.
Another common problem is where parts of the old system are still connected, a remote sounder, bell or buzzer in
another part of the system.
• Make sure the old power supply is switched off and disconnected from the system.
Do not attempt to keep the old system running on the same cables as you are installing the new system, you are most
likely to damage both systems and delay completion.
• Beware of Multi-core cables.
Multi-core cable is often used on older systems where every call point requires an individual connection back to the
display panel. This cable must be 80 pair cable (160 cores) is quite common. If you are using multicore cable you
should only use two cores within the multi-core length. If this cable is too small to connect the amount of current units
required, then this cable should be replaced with a cable of the SPINE specification.
When using the existing cabling, normally there is one cable back from each call point. In this instance, we would
connect several call points cables together (to a maximum of 25 current units) and connect them to one single output of
the FJB. Once the existing cabling is connected, additional spurs can be run from the FJB for new extensions as shown
above.
Typical New Installation.
CP CP CP CP CP CP CP CP
CP
CP CP
CP CP CP CP CP CP CP CP
D
LCD
CP CP
DM
CP CP CP
CP CP CP CP CP CP
LCD
FJB
FJB
PSU
FJB
FJB
PSU
FJB
BPS
FJB
The above diagram shows the FJB1 in use
showing four spur outputs. Always locate the
FJB2 in a central location (extending the spine
to a central location if necessary) minimising the
length of the individual cable spurs.
On the right, we are showing two buildings with
the Spine cable running between floors and on the
three floor building, a Booster is located on the top
floor