Protection Circuitry - Krell Industries Power Amplifiers MDA-300/500 Owner's Reference Manual

E PROTECTION CIRCUITRY
There are no fuses in the MDA-300/500s. The amplifiers
are protected by a series of non-intrusive, opto-coupled
circuits that constantly evaluate the amplifier's operation.
Appropriate protecti'ce action exists for DC conditions,
stiort circuit, oscillatidn, AC power anomalies, high
ground resistance and out-of:phase ground. Collectively
tlae protection circuitry is designed to avoid damage to
the amplifiers or speakers caused by other d.efecti~e
components, faulty wiring, mishandling of the system oy
amplifier failure. When the protection, circuit is engage(l,
the a.mplifiers will shut off and short tlaeir output. After
resolving either the input or output problem the amplifi-
ers can 15e turned on.
The amplifiers also have circuit breakers on their
backpanel for the AC power. Should the button in the
center of the breaker pop out, push it in to reset the
breaker. If the amplifiers still do not come back on, call
Krell Industries.
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