currents
in
both windings
of
the exciter stator. This three phase
AC
current
is
then rectified
to
DC
excitation current
by
a three phase
full
wave rotating rectifier assembly, and fed directly to the main
revolving field via two lead wires secured to the shaft with nylon tie wraps. Residual magnetism (flux)
for initial voltage buildup
is
provided by small permanent magnets embedded, one per pole, in each
of
the pole cores.
7 SERIES
Tl
...
-
<-~~~~~~~~---~~~~~~~~--1
TO
IOSl<M
TIS TIS 3
Tl7
T~
Tl7T~
STATOR
TZ
2 TB
s
TS
3 SERI
014
sau~
TIB
II
9
T9
SERIES
T6
TIS
EXCITER
STATOR
MAIN
INTER-CONNECTIONS
LEADS BROUGHT OUT
MAIN EXCITER
MAIN EXCITER
Tl3
T13
Tl
T4
T14 T14
T2
TS
TIS TIS
T3
T6
T16
T16
TO
T7
T17 T17
T8
TIS
TIS
T9
Figure 1 CIRCUIT
DIAGRAM-
LIMA"' MAC REFRIGERATION DUTY ALTERNATOR
(For
clarity, only interconnections
of
one
phase
is
diagramed)
Temperature Rise.
Lima®
MAC Refiigeration Duty alternators are constructed with Class F insulating
materials on the stator windings, and
Class H materials on the rotating windings. These machines are
designed for continuous duty, and are conservatively rated at
80° C temperature rise over a maximum
ambient temperature
of
50° C. This rating
will
meet the continuous duty temperature rise requirements
for
Class F insulation
of
NEMA, CSA, IEC, and
all
popular marine classification societies.
Power Factor.
Lima®
MAC Refrigeration Duty alternators are rated at 80% (0.80) power factor. The
. principal design concept
of
the
Lima®
MAC generator
is
to provide electrical power to operate three
phase induction motor loads having operating power factors
in
the range
of0.8
to 0.92, with voltage
regulation
well
within public utility standards.
3
To Next Page
Loading...