Series -48VDC connection of individual front access batteries
Step 1.
If installing in a multiple tier rack or cabinet arrangement, always begin with the lowest shelf,
string A, place each the individual front access batteries on the shelf (typically 4 per level) with
approximately 1/2 inch spacing between the individual units. All the batteries should be placed with
terminals to the front of the rack / shelf. Remove and save terminal protectors.
Step 2. C&D recommends, prior to connection of inter-unit bus bars and lugged cables, the battery
terminals and all contact surfaces should be neutralized, cleaned, lightly brushed with a brass bristle brush
or scotch brite type pad and lightly coated with protective No-Ox-Id terminal grease. Use caution to avoid
fully removing coating and exposing copper insert.
Step 3a. Starting at the battery on the right, which is to be the positive (+) output, label it as number 1 and
then label the adjacent batteries (right to left) in ascending numerical order 2, 3 & 4.
Step 3b. If more than one 48 VDC string is within the enclosure, number the additional batteries the same
way. Identify the bottom string as string A with the string above if present as string B and soon.
Step 4. Using the provided inter-unit bus bar and hardware (bolt and washer), connect between battery 1’s
negative (-) terminal to battery 2’s positive (+) terminal as shown in Figure 4. Tighten bolt washer assembly
hand tight.
Step 5. Repeat, using the provided inter-unit bus bar and hardware (bolt and washer), connect between battery
2’s negative (-) terminal to battery 3’s positive (+) terminal. Tighten bolt washer assembly hand tight.
Step 6. Repeat, using the provided inter-unit bus bar and hardware (bolt and washer), connect between battery
3’s negative (-) terminal to battery 4’s positive (+) terminal. Tighten bolt washer assembly hand tight.
Step 7. Torque each of the above bolt washer assemblies as per the inch-pound specifications in Table 3 for the
appropriate product.
Step 8. Following the rack or cabinet manufacturers cabling guidelines attach the lugged power lead connections
to positive (+) of battery 1 and negative (-) battery 4 terminals verifying proper polarities are observed.
Step 9. Torque all remaining bolt washer assemblies as per the inch-pound specifications in Table 3 for the
appropriate product.
Step 10. Repeat for additional battery string if multiple strings are present.
Step 11. Install all protective terminal covers and use a utility knife or diagonal cutter to trim the cover as
needed allowing for proper cable routing.
Step 12. Verify charging equipment is set for proper float voltage of 2.25 to 2.30 volt per cell at 77°F at the
battery terminals (54 to 55.2Vdc for a nominal 48 volt battery).
Figure 5 – 24 volt string configuration (typical) 2 strings to be in parallel shown
RS02046/0514/CD
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