Conductors have resistance that opposes the current flow and produces a
voltage drop and heating. The resistance is directly proportional to the length of
the conductor and is inversely proportional to the thickness. Consequently, a
longer and thinner conductor will have higher resistance and will produce a
higher voltage drop and more heating. The size of a conductor for a particular
application will depend upon the maximum current it is required to carry and for
what distance. The size of a conductor is designated by AWG (American Wire
Gauge) number. The smaller the AWG number, the thicker the conductor. The
conductors should be sized for a maximum voltage drop of 2%. The cables
should be multi-stranded insulated copper cable rated for at least 90 º C and
preferably oil resistant. To purchase cables, please visit a welding or marine
supply store.
Cables for 24 VDC input and 12 VDC output connections.
The cables on the 24 VDC input side must be able to carry a max. current of
approx 18 A (for extreme conditions when delivering 21 A on the output at
current limit at lowest 24 V input battery voltage of 20 V). To limit voltage drop to
2%, use # 10 AWG for distance up to 6 ft. and # 8 AWG for up to 10 ft. The cables
on the 12 VDC output side must be able to carry the full 21 A current under
current limit conditions. To limit the drop in voltage to 2%, use # 10 AWG multi
stranded cables to connect to the load for a distance of up to 6 ft. and # 8 AWG
for a distance of up to 10 ft. Use female quick connect terminals (tab size 6.3
mm) on the ends of the cables to enable connection to the male tabs of the
terminal block.
External fuses on the input and output sides.
The input and output connections should be made through 32 V, 20A fast blow
fuses (For example “Bussmann” Type ATC-20 or ATM-20 automotive type fuses).
The fuses should be connected in series with the positive input and output
cables. The fuse on the 24 V input side should be as close to the battery positive
terminal as possible. This will prevent the possibility of overheating & melting of
the input side cables in case of short circuit on the input side cabling (A battery
can provide very large currents during short circuit condition)
WARNING:
The warranty will be voided if the above external fuses are not used
Battery Charging
The CPC-20 can also be used as a 13.8 VDC battery charger. It can charge a 12V
starter or ancillary battery from a 24V system.
SPECIFICATIONS
