| When
extended back-up time is required (more than 1-2 hours), a diesel
generator combined with a UPS having 5-10 min. back-up power often
provides the optimal solution. In the event of mains failure, DP300E
pulls power from the battery while the diesel generator is started
and stabilized. As soon as the supply is re-established by the diesel
generator, the DP300E provides the load with conditioned generator-supplied
power.
Before the introduction
of the innovative DP300E, combining UPS and generator power presented
a serious problem, with a traditional UPS, the thyristor controlled
rectifiers draw high inrush current to magnetize the rectifier input
transformer when switching back to normal operation. They also cause
a major distortion of the supply due to the commutation of the thyristors.
The generator must be significantly over-sized to prevent the generator
output voltage from being distorted, by commutation of the thyristors
in a thyristor controlled rectifier.
With the DP300E
series you can use diesel generators without over-sizing. In fact,
you can size to the same rating, because the sinusoidal input current
causes no distortion feedback to the generator.
For very sensitive
diesel installations the DP300E series can even be programmed for
soft start. When switching back to normal operation it slowly transfers
the load from battery to generator.
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