Generac Power Systems 53187 - Manual (Page 23)

PARTI
THE REVOLVING FIELD AC GENERATOR
1
SECTION 1.4- MAJOR COMPONENTS
Components in Generator Control Panel (Continued)
THE AC VOLTAGE REGULATOR:
The VoKage Regulator used on units w ith 10 inch
stator is show n In Figure 10. The Regulator has a single
red lam p (LED) w hich w ill rem ain on during operation
as long as stator AC pow er w inding "sensing* voitage is
avaiiabie. Three sets of leads connect to the Regulator
term inals as follow s:
D
Unregulated AC output from the stator excitation
w inding connect to the tw o term inals indicated by
"DPE*.
□ Sensing (actual) voltage signals from the stator
AC pow er w indings are delivered to the
Regulator term inals indicated by "SEN".
□ Rectified and regulated (DC) current Is delivered
to the Rotor w inding from Regulator term inals
Indicated by a"+" and
The Regulator provides over-voltage protection. On
loss of "sensing", the Regulator w ill shut dow n and
regulated excitation current to the Rotor w ill term inate.
A single adjustm ent potentiom eter perm its the gener­
ator's AC output voltage to be adjusted. Perform this
adjustm ent w ith the engine running at no-load and w ith
AC frequency at 62 Hertz (1860 rpm ). At 62 Hertz, set
the line-to-neutral AC output voltage to 124 volts AC; or
the line-to-line AC output voltage to 248 volts AC.
AC CIRCUIT BREAKERS:
Tw o AC output circuit breakers (CB1 and CB2) are
provided, one for each line of the 240 volts AC output
circuit. The trip rating of these breakers depends on the
rated m axim um am perage capacity of the generator.
Units rated at 8000 w atts (8.0 kW ) are equipped w ith AC
breakers rated at 35 am peres.
Schem atic Pictorial
1 1
SEE FIGURES 4 & 5 ON
PAGE 1.5-2 FOR W IRING
CONNECTIONS
Figure 11. AC Output Circuit Breakers
EXCITATION CIRCUIT BREAKER (CB4):
An AC circuit breaker, rated 5 am peres, is electrically
connected in series w ith W ires No. 2 and 2A betw en the
stator excitation w inding and the Voltage Regulator. If
the breaker should trip (open) due to an overload, loss
of excitation current to the Rotor w ill occur. Generator
AC output voltage w ill then decrease to a value that is
com m ensurate w ith Rotor residual m agnetism (about 2
to 7% of the unit's rated voltage). The breaker is self
resetting and cannot be reset m anually.
Figure 12. Excitation Circuit Breaker
PAGE 1.4-5