Overcurrent Protection; Output Control Circuit Protection Current Limit; Figure 1 - Output Channel Schematic - Maretron MPOWER CLMD12 User Manual

Voltage Input stud

2.5.1.1 Overcurrent protection

The overcurrent protection has two purposes: to protect the CLMD12 and to protect the load
circuits. The CLMD12 is protected by fast acting overcurrent latches in hardware that allow for
overcurrent conditions that will not damage the output control circuit. Load protection is
implemented in software and trip levels and delays are set in configuration (please refer to
Section 3.5.1.6 for details).
When an overcurrent condition is detected, the CLMD12 will latch the breaker off for the
remainder of the continuously powered interval unless commanded OFF and then ON again
through the NMEA 2000 interface.

2.5.1.2 Output control circuit protection current limit

The non-configurable output control circuit protection allows surge currents to occur without
tripping the overcurrent shutdown function. These surges are allowed any time the breaker is
ON according to a single time constant characteristic. Over-current levels are allowed for a
time that is inversely proportional to the magnitude of overcurrent according to a well-defined
curve that is tailored to prevent damage to the CLMD12. This protection cannot be disabled
and will trip instantaneously when a peak limit is exceeded. Continuous load currents above
the hard current limit will also trip the overcurrent latch.
Breaker factory current rating
Revision 1.6
Current Current
Sense Sense
FET
DRIVER
Figure 1 – Output Channel Schematic
5A
10A
12A
55 K
Peak Current Limit
70A
140A
156A
Channel
Output
36 V
Hard Current Limit
7.5A
12A
20A
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