Lab.gruppen C Series 5:4X - Manual (Page 29)

C Series C 20:8X, C 10:8X, C 10:4X and C 5:4X Operation Manual rev. 1.1.4
Operation and Performance
22
20 Hz 10 kHz 20 kHz 30 kHz
- 6 dB slope
VHF protection
operation area
Max. Peak
output power
Max. Continous
output power
Output
power
Attack time
VHF protection
Slow
Fast
20 Hz 10 kHz 20 kHz 30 kHz
Figure 6.6.2: VHF protection operational area
The VHF protection is indicated by a yellow LED on the amplifier front panel, with output muting for six seconds
when active. It is reported as a fault via the NomadLink network on the DeviceControl GUI.
5.6.3 DC protection
DC protection is implemented on each output to prevent damage to connected loudspeakers. DC present at
the output will trigger muting and illuminate the fault LED indicator. Any DC present at the output indicates a
hardware malfunction that requires servicing of the amplifier.
5.6.4 High-impedance warning (open load)
A high-impedance (open load) condition is indicated when an input signal above approximately -29 dB is
detected and no functioning loudspeakers are connected to the amplifier. The fault in indicated by a red Sig/
Hi-imp LED. The indicator is green when a valid load is present under the same input signal conditions
Since the high-impedance detection initially triggers
only when the input signal rises above -29 dB, it
might cause the indicator to first turn green, and then
orange, even in situations where no speaker is
connected.
5.6.5 Low-impedance protection (short circuit)
A low-impedance or short circuit fault is detected when current draw is high (Current Peak Limiter active) and
when, simultaneously, output signal is low. When this occurs, the amplifier protects the output stage from
damage by muting the output signal and bypassing the circuits. Indication of this fault is a constant orange