Nautel NAB05E, Technical Instructions, Page: 28 / 45

48 VOLT BATTERY CHARGER
NAB05E
Page 5-3
01 September 2004
(m) Output voltage of variable dc power supply
shall be within 0.5% of the battery bank's fully
charged, open circuit, terminal voltage
[determined in step (a) of paragraph 5.3.2].
(n) Repeat step (j), simulate a 10% decrease in the
ac power source by setting the variac's output to
10% below the nominal V ac and then repeat
steps (l) and (m).
(o) Turn off the battery charger (set its
POWER
switch
OFF
and verify
POWER
lamp turns off).
(p) Disconnect test leads of oscilloscope and
variable dc power supply.
(q) Reconnect the power transformer's 75-0-75 V ac
secondary to the battery charger's switched full
wave rectifier. Connect wire #4 to T1-5 and
wire #5 to T1-7.
(r) Reconnect negative lead from battery bank to
TB2-1 of the battery charger.
(s) Connect a 5 ampere dc ammeter between TB2-2
and the positive leads of the battery bank.
Ensure positive terminal of ammeter is
connected to TB2-2.
(t) Discharge the battery bank or simulate a deeply
discharged condition by reconfiguring the
battery bank for a nominal 36 V dc terminal
voltage (remove one 12 volt battery).
(u) Set the variac's output to 230 or 115 V ac (ac
power source for battery charger).
(v) Turn on the battery charger (set its
POWER
switch
ON
and verify
POWER
lamp turns on).
(w) The ammeter reading shall be the desired charge
current (not to exceed 3.0 amperes) as
determined in step (b) of paragraph 5.3.2.
(x) Simulate a 10% increase in the ac power source.
Set the variac's output to 10% above the
nominal V ac and verify the ammeter reading
does not increase by more than five percent.
(y) Simulate a 10% decrease in the ac power
source. Set the variac's output to 10% below the
nominal V ac and verify the ammeter reading
does not decrease by more than five percent.
(z) Turn off the battery charger (set its
POWER
switch
OFF
and verify
POWER
lamp turns off).
(aa) Disconnect the variac and connect ac power
source wiring directly to the battery charger as
detailed in step (d) of paragraph 3.8.3.
(ab) If battery bank was reconfigured to simulate a
discharged condition in step (t), restore it to its
original (48 volt) configuration.
(ac) Partially discharge the battery bank to ensure it
will require a charging current when the battery
charger is turned on.
(ad) Turn on the battery charger (set its
POWER
switch
ON
and verify
POWER
lamp turns on).
(ae) Note the interval of time between charging
periods (ammeter current will drop to 0).
(af) Simulate an increase in temperature at the
battery bank by heating its temperature
transducer with a controlled heat source (heat
gun).
(ag) Verify the interval of time between charging
periods increases as the sensed temperature
increases.
(ah) Discontinue heating battery bank's temperature
transducer.
(ai) When the battery bank is fully charged (inter-
vals between charging periods are in excess of
60 seconds), 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.