CURRENT LIMIT CHARACTERISTICS
HSP power supplies provide two different current limiting modes for different applications; selection of the desired mode is accomplished via switch S1-3, accessed through the top cover of the HSP. The following describes the operational differences and selection method of each:Continuous Limiting: This is the factory-set (default) mode of operation. When the output current of the power supply reaches the programmed current limit, the output regulator switches to current mode operation and maintains the output current by modulating the output voltage; this operating mode is maintained indefinitely, and recovery to voltage regulation mode is automatic upon reduction of the output current below the current limit point. This mode is ideal for high-power battery chargers and applications where operation in current regulation mode is normal, or where immediate recovery from an overload condition of any duration is critical.
NOTE: HSP power supplies are designed to maintain continuous delivery of 110% of rated current indefinitely. When operating parallel/redundant power supply configurations in continuous limiting mode, the user must size the power supply/load interconnection conductors to withstand the total maximum load current available from all of the paralleled power supply modules.
Undervoltage Lockout: This mode is enabled when S1-3 is set to ON. The crossover from voltage- to current-mode operation is the same as for Continuous Limiting; however, after approximately 15 seconds, the output load regulation circuit is locked off via the overvoltage protection latch , requiring the user to recycle source power to restart the power supply. This mode permits automatic recovery from short-term overloads, but eliminates the danger of overheating and damage to the load and load wiring due to continuous exposure to high current; this is especially useful in redundant power systems, where the continuous overload current of all of the paralleled power supply modules can be in excess of twice the normal load current. As the circuit is triggered by the occurrence of an output undervoltage condition, this circuit can also protect circuits which may be unduly stressed in the presence of an extended undervoltage condition; an example of this are batteries, which can be damaged by discharge voltages below a specified minimum.
NOTE: When undervoltage lockout mode is enabled, it is necessary to also enable the Remote Reset function in order for the Remote Inhibit function to operate properly.
