Open Circuit Transformer Test - Cushman MINUTE MISER Technician's Repair And Service Manual

ELECTRICAL SYSTEM AND BATTERY CHARGER
Read all of Section B and this section before attempting any procedure. Pay particular attention to all Notes, Cautions and Warnings
Some transformer leads may be aluminum wire
and a solder must be used on these wires that
is intended for use on aluminum, such as Alcoa #807 solder
with Alcoa #69 flux. If these materials are not available locally,
contact the Lester Electric Factory.

Open Circuit Transformer Test

Failure of the transformer may be caused by natural
aging or premature shorting of adjacent coil turns or over
heating damage. The most common cause of trans-
former over heating and premature burn-out is the result
of misuse, connecting the charger to a battery system of
lower voltage than specified on the charger. Darkening of
No Load Open Circuit Transformer Secondary Coil AC Voltage
Charger Voltage
(Volts DC)
24
Fig. 8 No Load Open Circuit Transformer Secondary Coil AC Voltage
The readings are approximate and the transformer fail-
ure is indicted when the measured voltages are signifi-
cantly lower than those calculated in the table. DC
voltages measured at the charging leads are about half
the transformer test voltage amount.
Transformer secondary voltage measurements made
with the resonant capacitor connected can occasionally
result in noticeably higher readings than expected. No-
load transformer instabilities and peculiar wave shapes
can increase these voltage readings. This is particularly
true when using digital meters, as several models get
confused with other than pure sine-wave AC or pure rip-
ple free DC.
Page H-10
all the transformer secondary coil windings is an indica-
tion of possible over heating damage.
tor voltage can be as high as 660 volts AC. Use
extreme care when working near the capacitor termi-
nals. High voltage can cause shocks, burns or death.
Determine whether the transformer secondary coil is
within factory specification (Ref Fig. 8 on page H-10).
Qty. of Batteries
In Series
4
Repair and Service Manual
! !
Resonant Capacitor
Connected
54 To 66 Volts
HIGH VOLTAGE :
With the charger operat-
ing, the charger capaci-
Resonant Capacitor
Disconnected
36 To 44 Volts