Guardian Technologies 4758 Section, Description & Components, Part, Excitation Circuit Breaker

SECTION 2.1

DESCRIPTION & COMPONENTS

PART 2

AC GENERATORS

Figure 5. Excitation Circuit Breaker

VOLTAGE REGULATOR:

A typical voltage regulator is shown in Figure 6. Unregulated AC output from the stator excitation winding is delivered to the regulator’s DPE terminals, via Wire 2, the excitation circuit breaker, Wire 162, and Wire 6. The voltage regulator rectifies that current and, based on stator AC power winding sensing, regulates it. The rectified and regulated excitation current is then delivered to the rotor windings from the positive (+) and negative (-) regulator terminals, via Wire 4 and Wire 1. Stator AC power winding sensing is delivered to the regulator "SEN" terminals via Wires 11 and 22.

The regulator provides "over-voltage" protection, but does not protect against "under-voltage". On occurrence of an "over-voltage’ condition, the regulator will "shut down" and complete loss Of excitation current to the rotor will occur. Without excitation current, the generator AC output voltage will drop to approximately one-half (or lower) of the unit’s rated voltage.

Figure 6. Typical Voltage Regulator

A single red lamp (LED) glows during normal operation. The lamp will become dim if excitation winding AC output diminishes. It will go out on occurrence of an open condition in the sensing AC output circuit.

An adjustment potentiometer permits the stator AC power winding voltage to be adjusted. Perform this adjustment with the generator running at no-load, and with a 62 Hz AC frequency (62 Hz equals 3720 rpm). At the stated no-load frequency, adjust to obtain a line-to-line AC voltage of about 252 volts.

MAIN LINE CIRCUIT BREAKER:

The main line circuit breaker protects the generator against electrical overload. See Specifications on Page 1 for amp ratings.

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