Nautel NAB05E, Технические инструкции

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48 VOLT BATTERY CHARGER
NAB05E
Page 5-2
01 September 2004
(f) Observing ammeter, adjust
CHARGE CURRENT
potentiometer A1R18 for the maximum
allowable charge current (not to exceed 3.0
amperes) as determined in step (b) of paragraph
5.3.2.
(g) If cells were disconnected to simulate a
discharged state in step (e), restore battery bank
by reconnecting them.
(h) Wait until battery bank is fully charged (inter-
vals in excess of 60 seconds between charge
periods).
(i) Measure the specific gravity and/or terminal
voltage of all battery cells.
-
Specific gravity should be as specified by
battery manufacturer for a fully charged battery.
-
The terminal voltage for each cell shall be the
voltage specified by the battery manufacturer.
(j) If charge level is too low, make a small
adjustment to
CHARGE VOLTAGE
potentiometer
A1R24 in a clockwise direction then repeat
steps (h) and (i).
(k) If charge level is too high, make a small
adjustment to
CHARGE VOLTAGE
potentiometer
A1R24 in a counter clockwise direction and
then partially discharge the batteries until
charging resumes. Repeat steps (h) and (i).
5.3.4 ADJUSTMENT METHOD 2 (Using all
test equipment listed in table 1-2):
(a) Verify requirements of paragraph 5.3.2 have
been completed and battery charger is turned off
(it's
POWER
switch is set to
OFF
).
(b) Interface ac power source and the battery
charger with a variac that will accommodate
changing the ac voltage being applied to the
battery charger ±10% from nominal. Preset the
output of the variac to 230 V ac or 115 V ac
depending on the ac source.
(c) Disconnect battery bank from battery charger,
by disconnecting the interconnecting wiring
from TB2-2 and TB2-1. Ensure disconnected
wires are not shorted.
(d) Disconnect the power transformer's 75-0-75 vac
secondary voltage from the battery charger's
switched full wave rectifier. Disconnect wire #4
from T1-5 and wire #5 from T1-7.
(e) Connect a variable dc power supply, that has
been precisely preset to the battery bank's fully
charged, open circuit, terminal voltage
[determined in step (a) of paragraph 5.3.2];
between TB2-1 (-) and TB2-2 (+) of the battery
charger.
(f) Connect an oscilloscope's test probe between the
junction of resistors A1R26/R27 and the dc
reference level (either side of A1R27).
NOTE
The dc reference level is not at ground potential. Use
isolated oscilloscope probes.
(g) Turn on the battery charger (set its
POWER
switch
ON
and verify
POWER
lamp turns on).
(h) Set
CHARGE VOLTAGE
potentiometer A1R24
fully clockwise. The oscilloscope waveform
should be a nominal 0.0 V dc trace.
(i) Slowly
adjust
CHARGE VOLTAGE
potentiometer
A1R24 counter clockwise until oscilloscope
waveform just switches to a nominal 12.0 V dc
trace.
(j) Reduce output voltage of variable dc power
supply by minimum of 2.0 V dc. The
oscilloscope waveform should be a nominal 0.0
V dc trace.
(k) Simulate a 10% increase in the ac power source.
Set the variac's output 10% above the nominal
V ac (ac power source for battery charger).
(l) Slowly increase output voltage of variable dc
power supply until the oscilloscope waveform
just switches to a nominal 12.0 V dc trace.