Lab.gruppen PLM 20000Q - Manual (Page 27)

Operation and Performance
21
PLM Series Operation Manual rev 1.2.3
PAL activity is indicated by the LED within the first soft button 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.
5.3.3.2 PLM 20000Q
The Power Average Limiter Active warning (PAL Active) will be displayed when the power supply’s maxi-
mum 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 Breaker Emulation Limiter feature is present only in the PLM 20000Q. The PLM 20000Q is a power-
ful device 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 mod-
eled 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 tripp-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 via the Lake Controller.
5.3.5 Under Voltage Limiter (UVL ™ )
The PLM 20000Q is equipped with an under voltage limiter. With mulitple powerful devices on a mains
distribution line, heavy current loads risk the reduction of voltage below that required for devices to function.
The PLM 20000Q’s UVL reduces the mains current draw when voltage drop below 80 V. The amount of
reduction applied increases as mains voltage drops towards 65 V, then at 65 V the power supply is shut
down. The mains supply is continually monitored and when sufficient voltage returns the power supply
automatically restarts.