Hobart 5359D Operation And Maintenance Manual page 51

OM 2012
(5) Charg'ing circuit resistti
This 0.5 ohm, 100 watt resistor (20) is requivq-'
LL~ on tractor-mounted uni:s crjly.
Its purpc~e is to
allow
the battery charging alternator to maintain a nea; ncrn-tal
voltage
in th e c lcctric go;erncr co;ltrol box supply circuit
when
the TOW
TRACTOR ENGINE is bzing started. Witho;rt !hb resister in tl\z circuit,
cranking ihe tow tractti engine can cause a sufficiznt voltage d;op in ihe
system to influence operation of the electric governor control box and cause
an overspeed condition which will curve the overfrequency relal, to oFrate
and shut off power to an aircraft. With the resistor in the circuit, alternator
charging copability is limited to approximately 4 urnperes at ol I times, and
battery charging will be done mostly by the tow fructor generator or alternatcr.
G . Voltage Regu latcjr
0
Th'e voltage regulator (Fig.
12) is located on the right side of the machi,ne iust back
of the engine compartment near the lifting yoke. On tractor and truck moutited
units,
0~ sfationory
units the regulator is accessible fo: adjrr;tment by opening
rear doors on the right side.
On tractor mounted units, which have a large panel on
the right side, the regulator is reached by removing the rear hood-type vent cover
on top of the canopy.
Although a separate regulator manual is supplied with the generator set, a biief,
working description is given here.
The voltage regulator is designed to provide 1% voltage regulation with .25-seccnd
recovery time for all loads up to 100% of rated load on a three-phase, four-wire,
115/200-volt, 400-Hz, brushless generator.
This regulator provides field excita-
tion power for the rotary exciter,
and regulates generator output voltage by vary-
ing the exciter field power as required to meet varying load conditions. Thus,
the generator output is held ot a constant voltage. The maximum continwous rat-
ing of this regulator is 4.0 amperes at 140 volts DC.
Aug 25/s
1-l
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