TM 9-4910-663-12
(17 ) Set DC AMMETER LOAD & STARTER OUTPUT CURRENT BATTERY CHARGE
CURRENT RANGE switch (S14, fig 2-1) and DC AMMETER FIELD CURRENT RANGE
switch (S30) to proper positions for current ratings of generator.
ator speed, and set MASTER LOAD DISCONNECT switch (S8, fig 2-2) to ON.
(19) Using LOAD SELECTION switches (S17 through S24, fig 2-2)
and VARIABLE LOAD control (R32), as applicable, increase load on
generator until rated load is reached, and vary generator speed
throughout speed range.
(20) Shock test generator and regulator, using MASTER LOAD
DISCONNECT switch (S8, fig 2-2), noting regulated voltage. Set switch
to OFF, then to ON to shock load.
(21) Increase loading slowly and observe slight drop off in
regulated voltage and leveling off of current reading when current
limiter comes into play.
(22) Decrease load to zero by setting LOAD SELECTION switches
(S17 through S24, fig 2-2) to OFF, and set MASTER LOAD DISCONNECT
switch (S8, fig 2-2) to OFF.
(23) Set BATTERY CIRCUIT SELECTOR switch (S6, fig 2-2) to OFF.
(24) When required by equipment manufacturer's test procedure,
perform differential voltage and reverse current tests as follows:
(a) Set FIELD CIRCUIT switch (S32, fig 2-2) to MANUAL position
and adjust generator voltage to within 2 to 4 volts of battery voltage
by rotating FIELD CURRENT 0 -30 AMPS (MAX) control (R26) clockwise.
Then, set BATTERY CIRCUIT SELECTOR switch (S6) and MASTER LOAD DIS-
CONNECT switch (S8) to ON.
(b) Select appropriate setting of MILLIVOLT METER MILLIVOLT
DROP RANGE switch (S16, fig 2-1), and press MILLIVOLT METER MILLIVOLT
DROP PRESS TO READ switch (S34).
(c) Increase generator voltage very slowly while observing
MILLIVOLT METER MILLIVOLT DROP meter (M4, fig 2-1). Voltage should
increase and then decrease to zero when cut-off relay closes. Highest
voltage attained is the differential voltage. Release MILLIVOLT METER
MILLIVOLT DROP PRESS TO READ switch (S34).
(d) Decrease generator voltage very slowly while observing DC
AMMETER LOAD & STARTER OUTPUT CURRENT BATTERY CHARGE CURRENT meter
(M3, fig 2-1). Current should decrease, then indicate a reverse read-
ing, then come back to zero when reverse current cut-out relay opens.
Maximum reverse current attained is reverse current reading for par-
titular regulator under test.
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