Lab.gruppen PLM 20K44 Operation Manual page 20

5. Operation and performance
This condition indicates an attempt to draw excessive current at the output. The output is attenuated until the
output current falls below the maximum current rating. Limiting is performed by the ISVPL limiter in conjunction
with the selected ISVPL profile. Please refer to the Technical Specifications in Section 11 for further details
regarding ratings.
Note: If excessive current is indicated, check the output cables and examine the loudspeaker. If
impedance appears normal, you may rectify the condition by altering the ISVPL settings or lowering
input levels. CPL indication can be triggered by excessively low output impedance, possibly the result
of too many loudspeaker cabinets connected in parallel.
5.3.3. Power Average Limiter (PAL)
PAL activity is indicated by all four LED's to the left adjacent to the display flashing red, together with a PAL ACTIVE
warning message displayed on the screen. A warning is also displayed on the Lake Controller software.
The Power Average Limiter Active warning (PAL Active) will be displayed when the power supply's maximum rated
design parameters are reached. When this warning is displayed, gain limiting is being applied to the signal and the
ISVPL threshold is lowered accordingly.
5.3.4. Breaker Emulation Limiter (BEL™)
The PLM+ amplifiers are powerful devices that can draw a considerable amount of current from the mains supply.
The BEL models the temperature in the external breaker and limits the mains current to prevent it from tripping.
The BEL can be configured with both a breaker profile and a current value. The current value can be set from 5 to
32 Arms.
There are three different profiles available for selection:
• Conservative - The conservative profile allows no momentary current above the configured threshold.
• Fast - The fast profile models the time constant of the trip-curve corresponding to a fast breaker. It momentarily
allows current above the threshold to pass for a short time, leading to an increased modeled temperature. For
the limiter to disengage, the current must reduce below the threshold to enable the breaker to cool down.
• Universal - The universal profile models the time constant of the trip-curve corresponding to a slow breaker.
It momentarily allows current above the threshold for a longer time, leading to an increased modeled
temperature. For the limiter to disengage the current has to reduce below the configured current for the breaker
to cool down.
The BEL can be configured via the PLM+ front panel and within the Lake Controller software.
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PLM+ SERIES Operation Manual rev 1.0.0