Nortel DMS 100 Series Maintenance Manual page 25

The following figure shows the relationship of NTRX42AA circuit card
functional blocks.
Figure 2-2 NTRX42AA functional blocks
PDC feed
Breaker
ARLB
Automatic recovery from low battery
NT6L62AA ARLB hybrid a sample of each two-input battery feeds. The
ARLB provides two outputs to the NTRX42AA circuit card. An output can
control the two relays on each breaker module. When the sampled voltage
falls below -41.5V ± 0.5V, the relays power down to prevent breaker trip. The
relays remove the DRIVE or ENABLE signal. This action causes the
converters to shut down. The battery voltage must rise -44.5V ± 0.5V before
the RESET relay starts again.
Trip and enable circuitry
breaker. The trip occurs in response to alarm relay release in the associated
power converter. This circuitry provides the DRIVE or ENABLE signal for
the converters that require the signal.
DMS-100 Family Remote Switching Center Multi-Access Maintenance Manual XPM11 and up
BR
-48V
Trip
Trip circuits
and enable
CONVFAIL
(To alarm module)
Maintenance overview 2-9
DRIVE (ENABLE)
BR
CONVFAIL
ON/OFF
RESE
T
ILOKOUT
ILOKIN
The NTRX42AA sends the
A transistor circuit trips the associated circuit
To converter
To interlocked
NTRX42
(if required)