Bell Intercom System BSX User Manual
8
allowing a space between the speech unit and the inside surface of the panel (ie grill).
The connections affecting the speech operation are CHROT to the speech unit and R
O T to the phone; R carries speech from phone to panel and T from panel to phone with
O being the common negative; C & H carry power to the speech unit where C is
+12VDC and H is -12VDC ( H & O are connected together internally within the speech
unit).
O T to the phone; R carries speech from phone to panel and T from panel to phone with
O being the common negative; C & H carry power to the speech unit where C is
+12VDC and H is -12VDC ( H & O are connected together internally within the speech
unit).
To simplify testing the speech of either telephone or speech unit ensure 12VDC is correct
at C (+) & H (-), then temporarily connect R O T of the speech unit to R O T of the
telephone with a short length of cable.
at C (+) & H (-), then temporarily connect R O T of the speech unit to R O T of the
telephone with a short length of cable.
4.
While the telephone is active for speech the Lock button on the phone (lower) should
now be pressed; this should trigger the operation of the lock release for approx. 3
secs (or another specified time) and then immediately disconnect the call (LED on
relay board goes out).
now be pressed; this should trigger the operation of the lock release for approx. 3
secs (or another specified time) and then immediately disconnect the call (LED on
relay board goes out).
Lock Release Outputs
If the lock release cannot be made to operate then the output from the control PCB should be
verified with a voltmeter whilst disconnected. Assuming the output is correct, check the cables
as well as determining that the lock release is of the correct specification and connected to the
correct failsafe or failsecure terminals.
verified with a voltmeter whilst disconnected. Assuming the output is correct, check the cables
as well as determining that the lock release is of the correct specification and connected to the
correct failsafe or failsecure terminals.
Installing the Battery
The battery (if required) should be installed only after all tests on the system have been
completed and any faults have been cleared. Take care not to inadvertently short out the
battery terminals as the available current (200A) may burn or overheat cables and other metal
objects. Once installed the battery is safe and fuse-protected. The battery sits on the base of
the control cabinet and is connected to the free spade connections already provided. Ensure
the correct polarity is observed; the red wire with the red spade terminal goes to the battery
positive terminal (also red).
completed and any faults have been cleared. Take care not to inadvertently short out the
battery terminals as the available current (200A) may burn or overheat cables and other metal
objects. Once installed the battery is safe and fuse-protected. The battery sits on the base of
the control cabinet and is connected to the free spade connections already provided. Ensure
the correct polarity is observed; the red wire with the red spade terminal goes to the battery
positive terminal (also red).
NOTE: The battery will be shipped in a partial state of charge and may require charging
for several hours before use.
for several hours before use.
Now test the system again with any telephone, firstly with the mains on and secondly with it
off. If the system fails to operate satisfactorily when the mains has been failed then check the
fuses and also the battery voltage (should be 13.8V +/-0.25V). If the battery voltage is
low then allow several hours for it to charge with mains power present and test again.
DO NOT allow the system to operate for a protracted period on battery only (ie mains
switched off) or the battery may be irreversibly damaged by deep discharge.
off. If the system fails to operate satisfactorily when the mains has been failed then check the
fuses and also the battery voltage (should be 13.8V +/-0.25V). If the battery voltage is
low then allow several hours for it to charge with mains power present and test again.
DO NOT allow the system to operate for a protracted period on battery only (ie mains
switched off) or the battery may be irreversibly damaged by deep discharge.