Lab.gruppen C Series 88:4 - Manual (Page 28)

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5. Operation and Performance
C Series C 88:4, C 68:4, C 48:4, C 28:4 and C 16:4 Operation Manual rev 2.2.3
5.5.7 Temperature protection
Thermal measurement points are provided on each output channel as well as on the power supply. If these
sensors detect temperatures above the specified maximums, a high temperature warning will be indicated by
a flashing Temp LED on the front panel. The warning also will be transmitted to the Device Control GUI via the
NomadLink network.
As the amplifier approaches a thermal protection threshold, the warning LED sequence will start with short “on-
time” bursts. If the amplifier continues to overheat and approaches the temperature limit, the flashing sequence
will be defined by longer and longer on-time bursts until the protection mode is activated.
If the temperature becomes too high to continue safe operation, the overheated output channel(s) will be muted
until the temperature returns to an acceptable level.
Fully active temperature protection (with muting) is indicated by a constantly illuminated Temp LED. It will also
be indicated as a fault via the NomadLink network on the DeviceControl GUI.
Temperature measurements will continue at six second intervals. The output will un-mute when the channel or
power supply returns to a safe operating temperature.
5.5.8 Power Average Limiter (PAL)
The Power Average Limiter (PAL) controls the current-drawing relationship between the power supply and the
mains inlet. PAL limits the maximum average power consumption according to the power supply capabilities,
ensuring that the PSU will not overload. In addition, in the larger models that potentially could pull more current
from the mains than the mains fuses are specified to handle (more than 16 A), PAL limits the amplifier’s maxi-
mum current draw to prevent blowing the mains fuse.
5.5.9 Soft-Start
High powered amplifiers with inadequate inrush limiting can pull considerable current from the mains at turn-
on. This can result in fast acting mains breakers tripping. Such is not the case with C Series amplifiers in most
circumstances.. The C Series amplifiers have very low inrush power as the capacitors are charged slowly, and
in a controlled manner, ensuring that breakers will not trip.
Several amplifiers will, under normal conditions, be able to be powered up simultaneously. If you do experience
problems powering up multiple amplifiers simultaneously (normally experienced only in very large installations),
use the NomadLink network and the NLB60E to establish a power sequence with pre-set delays before the
start-up of each subsequent amplifier.