Unipower ARE Series, Инструкция по установке и эксплуатации

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ARE Series Chargers
RS-759, Rev. 11 3-1
3. TROUBLESHOOTING
3.1 GENERAL DESCRIPTION OF OPERATION
The main components of ARE Series power supplies are shown in the accompanying block diagram. AC input
power is applied through the input circuit breaker to the power transformer. The circuit breaker provides over-
current and fault protection in case of malfunction or a short circuit in the input side of the equipment.
The power transformer in ARE Series power supplies is of the ferroresonant type. This class of transformers has
the output coil on the same leg of the core as the resonant winding. This winding, together with the same resonant
capacitor, maintains the core at a high level of saturation, resulting in fairly constant output voltage against
changes in the input voltage. The high reactance of this type of transformer provides protection against overload
and short circuit of the output.
To improve on the output voltage regulation of ferroresonant transformers against changes in load and input
frequency, the ARE Series power supplies employ UNIPOWER’s own controlled – ferro technique, which
controls the level of core saturation.
This is accomplished by shunting the resonant circuit with a triac in series with an inductor. The electronic
voltage/current control senses the start of the resonant capacitor charge cycle and also senses the output voltage
level, which it compares with a reference voltage. The error signal that results determines the instant the triac
turns on the interrupt the capacitor charge cycle and thus maintains the core saturation at the desired level.
Output current limit circuitry is also on the control board. When the current exceeds a preset level, a signal
proportional to the output current, developed by the DC ammeter shunt, overrides the voltage regulator and
maintains output current at the preset level. If a fault occurs, resulting in a higher output voltage, it is sensed by
the high voltage shutdown circuit, which trips the shunt trip AC breaker turning off the unit.
The power rectifier, which converts the AC voltage from the transformer into DC voltage, consists of silicon
diodes arranged in a full-wave circuit. The output of this rectifier is filtered and supplied to the battery and the
load through the DC circuit breaker.
FIGURE 3-1: BLOCK DIAGRAM FOR A TYPICAL “ARE” POWER SUPPLY
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