www.nationalrailwaysupply.com
1-800-357-3572
6
38542D
Current Limit Adjustment
The current limit adjustment should be set to a level
that is below the charger output when sourcing the
minimum DC load of the system and floating the fully
charged battery set. The current limit adjustment is
factory-set
to
approximately
400
mA
(fully
clockwise), which should work for most applications.
If the minimum DC load of the system combined with
the battery float current is above approximately 500
mA, leaving the current limit adjustment at the
factory setting of 400 mA is recommended. If an
adjustment is required, it can be adjusted between
approximately 400 mA and 70 mA. Setting the
current limit adjustment below approximately 100 mA
is not recommended due to internal charger DC
current that can still exist and be monitored if the
charger DC output is disconnected from the load and
battery set.
Adjustment Procedure
A small screwdriver (3/32 inch maximum blade
width) is required to change the current limit
adjustment.
With AC power applied to the charger input and the
charger DC output connected to the load and fully
charged battery set, monitor the charger output
current until it stops decreasing and levels off at the
minimum system current. Ensure that the current
limit adjustment is turned fully clockwise, which will
set the current limit at approximately 400 mA. If the
LED is on and the CLOSED relay contact is closed
when the current limit adjustment is turned fully
clockwise, leave it in that position. If the LED is off
and the CLOSED relay contact is open when the
current limit adjustment is turned fully clockwise, turn
it slowly counterclockwise until the LED turns on and
the CLOSED relay contact closes. Turn the current
limit adjustment approximately 1/8 of a turn
counterclockwise from this switching point. Remove
AC power from the charger to verify that the current
monitor/alarm is functioning. The LED should turn
off and the CLOSED relay contact should open.
Current Monitor Specifications
CURRENT MONITOR/ALARM RELAY CONTACT
RATINGS:
1A at 30 Vdc
0.5A at 120 Vac
TERMINAL CONNECTIONS:
20
– 16 AWG wire, strip length of .312 - .359
inches (8
– 9 mm)
10. MAINTENANCE
The battery charger requires minimal maintenance.
It should be kept clean and all connections are to be
periodically tightened.
BE SURE THE CHASSIS IS
SECURELY GROUNDED.
If any problem cannot be
resolved, consult the nearest NRS service agent at
1-800-357-3572.
11. SERVICING
If the battery charger operates improperly, follow the
steps below.
a. Begin by checking the voltage switches to
verify their settings against the specifications
of the batteries.
b. Check the AC voltage selection switch for
the proper setting.
c. Check the fuses to make sure they have not
blown.
d. Check the circuit breaker to see if it has
opened and push it in to reset it, if
necessary.
e. Check the polarity between DC output and
the battery and make sure their connections
are tight.
f.
Remove the small cover on the front of the
charger and make sure all of the binding
posts nuts are tight.
g. If the steps above do not solve the problem,
contact your local NRS service agent at
1-800-357-3572.
12. CHARGER SPECIFICATIONS
AC INPUT VOLTAGE:
115 VAC (108-128) or 230 VAC (216-256)
AC INPUT CURRENT:
16.0 amps for 115 VAC (full power)
7.5 amps for 230 VAC (full power)
AC INPUT FREQUENCY:
48
– 65 Hertz (single phase)
AC LINE REGULATION:
For a constant output current at 2.23 volts/cell
+ 5.6% for 18 cells
+ 13.1% for 12 cells
AC FUSES:
MDA 12 or equivalent
DC OUTPUT:
Voltage range
20.0
– 35.0 + 0.2 volts
Current Maximum 30.0 + 0.5 amps
