Figure 2-8 Mpps-Ii Block Diagram; Figure 2-9 Mpps-Ii Power Pack - Motorola STARLINE SERIES Installation And Operation Manual

Figure 2-8 illustrates a block diagram of the MPPS-II power pack:
Figure 2-8
MPPS-II block diagram
EMI Filter
60/90
Vac
Figure 2-9 illustrates the MPPS-II installed in the upper half of the MB-HSG:
Figure 2-9
MPPS-II power pack
The MPPS-II also contains a two position
or 55 Vac. The MB*/* is shipped with the selector in the
configuration. The selector should be switched to the
sets the start-up voltage at 55 Vac. Because this is only 5 V below 60 Vac, it is not practical to
switch to in a 60 Vac system. There is no damage to the amplifier if the selector is not
HI
changed from the standard
supply does not turn on until the proper input voltage, 38 Vac or 55 Vac, is reached. This
prevents excessive loading of the system power supply during turn-on after a system shutdown.
Bridge
Preregulator
rectifier
Overvoltage
and
power-factor
correction
HI
LO
AC TEST POINT
NO USER SERVICABLE
PARTS INSIDE
VOLTAGES IN EXCESS OF
300 VOLTS ARE PRESENT
USE CAUTION WHEN MAKING
INTERNAL ADJUSTMENTS UNDER COVER AND MAY
WITH COVER REMOVED BE PRESENT FOR SEVERAL
MINUTES AFTER POWER
SEE INSTALLATION MANUAL IS REMOVED
FOR SERVICE
24V TEST POINT
/ selector that sets the start-up voltage for 38 Vac
LO HI
setting. However, changing the selector ensures that the dc
LO
Overview
Precision
Isolation
regulator
transformer
FTEC
460132-001
MPPS-II
position which is the standard
LO
position only for a 90 Vac system. This
HI
MB*/* Installation and Operation Manual
2-7
24
Vdc