Regal Marathon Lima Mac Installation And Operation Manual page 5

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