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*Voltage drops for pvc insulated cables are ex table 9D1
of the IEE Wiring Regulations.
The above are based on a maximum conductor
temperature of 70°C in an ambient temperature of 30°C.
Note: that it is not practical to use table 9D1 of the IEE
Wiring Regulations for larger sizes. We are after all talking
about short duration power flow not continuous ratings for
the starter motor. At the end of the day what matters is
the voltage at the starter motor terminals before starting
and whilst cranking, all without destroying the
insulation on the cables.
KEYSWITCH TERMINATIONS
The standard panel keyswitch can be used to tap off a
switched positive ignition feed to power additional gauges.
In this way these gauges will only be live whilst the
engine is running, the engine is starting or the heaters are
being used.
For silver keyswitches, the terminal to achieve this ignition
switched positive is marked ‘AC’.
For panels without any keyswitch, gauges can be driven
from the 1 mm2 brown wire which terminates at 11 way
connector terminal 4. This is a lower power switched
positive, any additional power required from this
connection must be feed through a relay, as noted below.
Note: these keyswitch terminals are rated at 10 amps
maximum, since they are already utilised for panel and
alternator feeds Beta Marine recommend any additional
requirements from these terminals must be fed through a
relay. This relay should then be connected to it’s own
fused positive supply directly from the engine battery.
Beta drawing 202-06421 illustrating the wiring of a
typical electric fuel lift pump with ignition switched relay
can be supplied upon request.
70mm
2
Cable
Engine Cranking Amps Cable Volt drop* Max length, both cables added together
Up to Beta 38 100 0.00063V 12.7m
Up to Beta 50 120 0.00063V 10.5m
Up to Beta 60 170 0.00063V 7.5m
Up to Beta 105 210 / 250 0.00063V 5.0m
Beta 150 333 0.00063V 3.8m
1640_Aug_2013.qxd:beta 1660 manual 18/11/13 10:48 Page 23
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