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1-800-357-3572 

38934B 

Low Current Set Point Adjustment 
 
The low current set point 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 low current 
set  point  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.   
 
Adjustment Procedure 
 
A  small  screwdriver  (3/32  inch  maximum  blade 
width) is required to change the low current set point 
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  low 
current set point adjustment is turned fully clockwise, 
which  will  set  the  low  current  set  point  at 
approximately  400  mA.    If  the  LED  is  on  and  the 
CLOSED  relay  contact  is  closed  when  the  low 
current set point adjustment is turned fully clockwise, 
leave  it  in  that  position.    If  the  LED  is  off  and  the 
CLOSED relay contact is open when the low current 
set  point  adjustment  is  turned  fully  clockwise,  turn  it 
slowly  counterclockwise  until  the  LED  turns  on  and 
the  CLOSED  relay  contact  closes.    Turn  the  low 
current  set  point  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/Alarm Specifications 

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.  VOLTAGE MONITOR/ALARM 

The  ELC-24/30-CVM-D  battery  charger  includes  an 
integrated  voltage  monitor/alarm  that  monitors  the 
DC  voltage.    Unless  the  optional  VOLTAGE 
MONITOR  BATTERY  SENSE input available on the 
front of the charger is remotely wired to the terminals 
of the battery, the DC voltage is monitored internally 
at the charger output.  If the DC voltage rises above 
the  HIGH  VOLTAGE  (HV)  SET  POINT  setting,  the 
green  BELOW  HV  SET  POINT  LED  indicator  is 
turned off and the Form C, dry contact alarm relay is 
actuated.    If  the  DC  voltage  falls  below  the  LOW 
VOLTAGE  (LV)  SET  POINT  setting,  the  green 
ABOVE  LV  SET  POINT  LED  indicator  is  turned  off 
and the Form C, dry contact alarm relay is actuated.  
The  voltage  set  point  switches,  LEDs,  relay 
terminals,  and  optional  battery  sense  input  are 
accessible  on  the  front  of  the  charger  (see  Figure 
10.1). 

 

Figure 10.1 

Summary of Contents for ELC-24/30-CVM-D

Page 1: ...l which may cause burns Do not get in eyes on skin or clothing If the gelled or liquid content of the batteries contacts the skin or clothing wash the area thoroughly with water In the case of contact with the eyes flush immediately with clean water for 15 minutes and obtain medical attention e Connect or disconnect the battery plug only when the charger output is off to prevent arcing or burning ...

Page 2: ...is not being used or the temperature probe is working improperly Temperature compensation uses a temperature reference of 77 F 25 C a voltage reference of 2 23 volts the voltage of a standard gel cell battery at 77 F and a compensation value of 3 0 mV per F or 5 4 mV per C The equivalent equation for the compensated voltage is Vcomp V k t 77 F Where V is the voltage of the battery at 77 F t is the...

Page 3: ...g flanges are configured for an EIA 19 483mm rack for a forward mounting arrangement note the width from the outer edge of one mounting flange to the outer edge of the other mounting flange is 19 15 16 Fasteners to match the thread of the rack should be used in all 7 rack mounting horizontal slots on each of the 2 mounting flanges 14 rack mounting slots total to maximize the mounting integrity The...

Page 4: ... CAPACITOR 7 TEMPERATURE PROBE The external temperature probe is an optional way of extending battery life by using temperature compensation One end of the temperature probe cable has a three pin plug which plugs into a receptacle labeled TEMP PROBE on the front of the charger The other end of the cable has the temperature sensor sealed either in a terminal or small metal box WARNING IT IS IMPORTA...

Page 5: ...ewdriver 3 32 inch maximum blade width is required to insert or remove a wire from a relay terminal WARNING BE CAREFUL IF AN UNINSULATED METAL TOOL CONTACTS BOTH THE GROUNDED CHARGER CASE AND A RELAY TERMINAL PUSH IN TAB THIS WILL CAUSE A POTENTIALLY DAMAGING AND OR DANGEROUS ELECTRICAL SHORT Current Monitor Alarm Operation Table 9 1 outlines the operation of the LED and relay based on the status ...

Page 6: ...e it in that position If the LED is off and the CLOSED relay contact is open when the low current set point adjustment is turned fully clockwise turn it slowly counterclockwise until the LED turns on and the CLOSED relay contact closes Turn the low current set point adjustment approximately 1 8 of a turn counterclockwise from this switching point Remove AC power from the charger to verify that the...

Page 7: ...small screwdriver to turn the switch so that the arrowhead on the slot is pointing to the desired number BE SURE EACH SWITCH IS SET ON A NUMBER AND NOT BETWEEN NUMBERS If a switch is set between numbers the corresponding LED will flash and the voltage monitor alarm will not function as intended Voltage Monitor Battery Sense Input Optional The voltage monitor alarm includes an optional VOLTAGE MONI...

Page 8: ...eset 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 13 CHARGER SPECIFICATIONS AC INPUT VOLTAGE 115 VAC 108 128 or 230 VAC 216 ...

Page 9: ...RCUIT BREAKER ASSEMBLY 31457S 1 AC SWITCH ASSEMBLY 27319S 1 AMMETER 50 AMP 14197S 4 BUSHING 1 29741S 1 TEMPERATURE TRANSDUCER 10 W TERMINAL 29742S 1 TEMPERATURE TRANSDUCER 30 W TERMINAL 14742S 1 HEATSINK ASSEMBLY W SCR 9 WIRE 15194S 1 HEATSINK ASSEMBLY W SCR 21 WIRE 23074S 1 SCR ASSEMBLY 50 AMP 21 WIRE 23073S 1 SCR ASSEMBLY 50 AMP 9 WIRE 15032S 2 OUTPUT CAPACITOR C 26 000 UF 55V 38604S 1 CAP ASSEM...

Page 10: ...www nationalrailwaysupply com 1 800 357 3572 10 38934B 15 WIRING DIAGRAM ...

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