Overcurrent Protection - Maretron MPOWER CLMD16 User Manual

CLMD16 User's Manual
There are three load shedding levels:
• Low
• Medium
• High (default)
Each channel has a load shedding priority which is user configurable.
The Medium and Low load shedding priorities have a user-configurable deactivation threshold and
an activation threshold voltage level.
The Load Shedding Medium Priority Deactivation-threshold voltages must always be lower than the
Low Priority Deactivation-threshold.
Load shedding will never turn off (shed) channels assigned to the High Load Shedding Priority.
The Electronic Circuit Breaker feature is fundamental to the CLMD16 product; the purpose of the
feature is to automatically disconnect a load from the supply when an electrical fault is detected to
protect the load and its supply wiring from damage.
The CLMD16 Electronic Circuit Breakers (ECB) trip behavior mimics the operation of traditional
circuit breakers. The time a mechanical circuit breaker takes to trip is governed by several factors,
including sensing time, unlatching time, mechanical operating time, and arcing time. In the CLMD16,
this is replaced by configurable parameters.
The ECB performs the following protective functions:
•
Overload Protection (long time delay trip function)
• Short circuit protection with delayed trip (short time pickup)
• Instantaneous short circuit protection (instantaneous trip function)
Each ECB uses a microprocessor to process the current signal and operate the circuit breaker
opening in case of fault. By digital processing of the signal, they provide the following protection
functions:
• Long Time-Delay trip function.
• Short Time-Delay trip function.
• Instantaneous trip function.
To mimic the function of traditional mechanical circuit breakers, it is possible to configure the time-
delay trip function through the NMEA 2000
if there is an over-current or thermal event-based trip characterized by an Instantaneous, Short, or
Long time delay curve. Each of these curves has an instant trip region, as shown in Figure 11.
21

Overcurrent protection

®
interface to suit connected loads. The CLMD16 can trip
__