Lab.gruppen PLM series Operation Manual

Also see for PLM 10000Q: Supplementary guide User manual addendum Specifications Quick start Technical data

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Lab.gruppen PLM series Operation Manual Manual pdf 28 page image

28 PLM Series Operation Manual rev 1.1.37. Operation and Performance* Note that these ratings are limited by the CPL (Current Peak Limiter) functions, not by ISVPL settings, due toamplifier channel current capacity.The ISVPL threshold may be set at any level between 17.8 V and 193 V via the PLM’s menu system. (SeeSection 9.12.2.5.1 or the Lake Controller User Manual PLM Addendum for details.) Even PLM model’s thathave a smaller peak output voltage can set the ISVPL threshold all the way up to 193 V. When a thresholdis set above the maximum capability of that model, the actual internal value will be limited to that modelsinternal ISVPL maximum. Hence the ISVPL threshold can be configured in Modules to protect at thespeaker maximum capabilities and the Module file is still cross-compatible with all PLM models. Notethat the maximum internal ISVPL setting of a particular model is greater than the 150 V maximum peakvoltage available from that model. Typically the internal maximum ISVPL Threshold allows for an overshootof 3V compared to that model’s maximum peak output voltage. This is to accommodate the small degreeof production spread of maximum output voltage that exists between PLMs. Allowing a maximum ISVPLsetting fractionally higher than the maximum safe output voltage under any condition ensures that severeclipping will never be encountered.7.3.2 Current Peak Limiter (CPL)The output Current Peak Limiter (CPL) ensures that the power output section will not be damaged by forcingit to deliver current levels at the outputs that exceed the maximum current ratings of the output transistors.The CPL keeps the output transistors within their Safe Operating Area (SOA). The CPL is non-adjustable.CPL activity is indicated on the power output channel LED (one of the four LEDs in the soft function buttonsto the right of the display). Activity on an affected channel results in a flashing red indication together with aCURRENT CLIP warning message displayed on the screen adjacent to the LED. A warning is also displayedon the controlling PC via the network.This condition indicates an attempt to draw excessive current at the output. The output is attenuated untilthe output current falls below the maximum current rating. (See section 13 – Technical Specifications forfurther details concerning ratings.)If excessive current is indicated, check the outputcables and examine the loudspeaker. If impedanceappears to be normal, you may rectify the conditionby altering the ISVPL settings or lowering inputlevels. CPL indication can be triggered by excessively lowoutput impedance, possibly the result of too many loudspeakercabinets connected in parallel.7.3.3 Power Average Limiter (PAL)The Power Average Limiter (PAL) controls the AC current into the power supply. Power consumption islimited to the rated design parameters of the power supply, ensuring that the PSU will never be overloaded.Also, high-power products such as those in the PLM Series can potentially draw more current (with outputdevices still within safe operating areas) than is allowed by the mains fuse.Only the 230 V version is fitted with a fuse. It is notpossible to source fuses with sufficient currentcapacity for the 115 V versions.