C&D Technologies 41-7525 VRLA Batteries (rack mounted systems) - Manual (Page 8)

Locating the Batteries on the Rack
The individual batteries should be placed on
the rack tier/shelf with 1/2" (1.27 cm) spacing
between the units. This is important to assure
the inter-unit connecting cables properly align
with the adjacent battery terminals and to allow
air space for proper cooling of the batteries.
When the batteries are being placed side to
side, all the batteries should be placed with the
terminals of the same polarity (POS. or NEG.)
to the front of the tier/shelf. Refer to Figures 4
and 5.
For stability reasons, the batteries should be
placed on the lowest tiers/shelves first.
CAUTION: Do not lubricate the rack rails or
battery containers with grease or other lubricating
compounds. Certain lubricating compounds will
cause deterioration of the battery plastic container
and/or the rack plastic components.
Battery Terminal Preparation
To minimize contact resistance, it is important
that the lead terminals of the batteries be
cleaned of any oxidation that may have
occurred during transportation and storage.
It is most convenient to clean them prior to
placing them on the rack.
Lightly brush the terminal contact surface areas
with a brass bristle brush, or the equivalent, and
then apply a light coating of the special antioxidant
grease, such as NO-OX-ID or NCP-2, to the
surfaces to protect the lead terminal from
further oxidation.
Numbering the Batteries
Once the batteries are placed on the racks,
they should be numbered for future identification
during maintenance, etc.
Refer to the system wiring schematic and starting
at the battery that is to be the positive output of
the system, label it as #1. Then label the batteries
in ascending sequential order as they would be
connected in series. The battery at the negative
output of the system should be the highest
number battery.
If individual strings are to be connected in
parallel, each string should be uniquely
identified (e.g. A, B and C).
Interunit Connections
The various batteries may be of different dimensions
and with different terminal configurations. This and
the anticipated load determine the wire size, lugs
and length of the cable to be used for the interunit
connectors. Refer to Table 1 and Figure 6 for the
typical connection configuration and cable to be
used for each part number of 12V VRLA battery.
In general, the wire size to be used is:
1. AWG #6 for loads of up to 90 amperes.
2. AWG #2 for loads of up to 150 amperes.
3. AWG #1/0 for loads of up to 250 amperes.
4. AWG #4/0 for loads of up to 400 amperes.
5. 2 each AWG #2/0 for loads of up to 600
amperes.
Lightly brush and coat with the protective grease
the contact surface area of the battery terminal
and interunit cable lug and assemble the interunit
connection per the relevant connection diagram of
Table 1. Torque the connection hardware to that
specified in Table 1.
As all the batteries are interconnected on each
tier/shelf the total open circuit voltage (OCV) of the
batteries on the tier/shelf should be verified as:
OCV per Tier = number of batteries per tier x
voltage per battery
41-7525/0514/CD 8 www.cdtechno.com
0.5”
Figure 6-Typical Inter-Unit Connections
(See page 11 for Specific Battery Models)