User Manual

11
Electrical Connections
Connecting cables between D400 and the battery bank or inverter should be appropriately
sized to minimise transmission losses. For low voltage machines transmission losses are
always a consideration, so it is advisable to keep cable runs as short as possible and be
prepared to use heavier gauge cable for longer runs.
Suggested cable conductor cross-sectional areas for a 12V machine would be:
0 - 10 metres cable 6 - 8 ²mm
10 - 20 metres cable 10 - 16 ²mm
20 - 30 metres cable 20 - 25 ²mm
For a 24 volt machine, the transmission losses are lower. Suggested cable sizes would be:
0 - 10 metres cable 2 - 3 ²mm
10 - 20 metres cable 3 - 5 ²mm
20 - 30 metres cable 5 - 8 ²mm
Note, cable sizing is always a‘trade off’ between the reduced electrical losses
associated with using larger cable, and the additional costs and difficulty of the installation.
The cable sizes recommended above will ensure acceptably high transmission
efficiencies
Where D400 is fitted to a tall mounting tower, ensure the weight of the hanging cable is
taken by a strain relief arrangement within the tower, rather than allowing all the weight
to hang on the D400 cable connection.
Fusing:
D400 is capable of producing very high currents. A line fuse must always be installed
in order to protect the D400. This is in addition to the fuses in the regulator output.
A blade-type 50 amp rated fuse and holder is supplied with 12 volt machines.
A blade-type 30 amp rated fuse and holder is supplied with 24 volt machines.
Note: This fuse should be installed between the turbine and the regulator and where a
braking switch is fitted, the fuse should be installed between the switch and the turbine.
Regulation
Where D400 is being used for battery charging we strongly recommend that a regulator is
installed as part of the system. The regulator’s function is to prevent battery damage
through overcharging. The regulator works by sensing battery terminal voltage and as a
pre-set upper limit is approached, the regulator progressively dumps output from D400 to
a pair of large, foil-wound resistors, where the surplus energy is lost as heat.
The 6TB regulator unit usually supplied with the D400 incorporates a charge splitter so its
two outputs can be connected to two independent battery banks which will be charged
simultaneously. The regulator will preferentially charge the lower of the two banks first.
Note: each output of the 12V regulator is protected by a 40 amp blade fuse. The outputs
of the 24V regulator are protected by 20 amp fuses.
The regulator should be installed within 1 metre of the battery bank where possible and
the dump resistors mounted horizontally in an area where air is free to pass over them for
cooling.
See wiring diagrams on pages 13 and 14.