Dynacord H 2500 Manuel d'utilisateur télécharger pdf (Page 32)

PowerH SERIES

32 Owner’s Manual

case of power outage, both output channels are instantly muted then the power amplifier is shut down

within only a few milliseconds.

Mains Circuit Breaker Protection

The power amplifier automatically reduces the output power whenever it is driven at high levels with

extremely low-impedance loads connected resulting in the chance that the mains circuit breaker reacts.

Therefore, adjusting the characteristics of the utilized circuit breaker in Amperes is possible via the LC

display. Especially at extremely high/low ambient temperatures or when connecting the power amplifier

together with other equipment to a single common automatic circuit breaker, it might become necessary to

manually set an Ampere value that differs from the circuit breaker’s nominal value to ensure that the Mains

Circuit Breaker Protection functions optimally. The following table outlines the allowable value ranges and

default settings for the two modes of operation at 120 V and 220-240 V.

The power amp’s CPU is acquainted with the temporal progression of the mains current consumption and

therefore can simulate the typical behavior of a mains circuit breaker. Nevertheless, pulse peaks allow

crest currents that can exceed the nominal value by a multiple. RMS measurement of the mains current

consumption allows the CPU to emulate the temperature curve of a circuit breaker’s thermal trip, which in

return enables the Mains Circuit Breaker Protection to let the power amplifier work till shortly below the

trigger level of the automatic circuit breaker. With typical concepts, especially for those without RMS

current measurement, output power reduction has to be applied much earlier. During the processing of

musical program material, the Mains Circuit Breaker Protection normally does not have to reduce the

power amp’s output power. At most, with settings that are noticeably below the pre-set values of 16 A or 30

A respectively, (which may be reasonable when operating multiple power amps via a single automatic

circuit breaker) output power reduction might become necessary to prevent the mains fuse from blowing.

Power-On Delay and Softstart

A Power-On Delay of up to 6.35 seconds can be programmed for the power amp via the LC display. Upon

pressing the mains switch the power amplifier does not start until the set delay time has elapsed. If several

power amps are operated on the same automatic circuit breaker, cascaded switch-on can be accomplish

by programming individually different power-on delays for the amps. This also prevents the magnetic trip of

an automatic circuit breaker from acting and thus disconnecting the power amplifiers from the mains

supply, when various amps are switched on at the same time. The internal soft-start function additionally

suppresses current peaks during power-on, which ensures trouble-free operation of PowerH SERIES

amplifiers even on very sensitive automatic circuit breakers.

Operation Minimum Maximum Factory Settings

120 V 6 A 40 A 30 A

220-240 V 6 A 30 A 16 A

Table 3.4: Mains Circuit Breaker Protection

1 2 ... 27 28 29 30 31 32 33 34 35 36 37 ... 147 148

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Dynacord H 2500 Manuel d'utilisateur Page 32