MoTeC PDM30 - Manual (Page 28)

MoTeC Configuration 25
to any PDM output and configured to turn on when the Global Error channel is
TRUE.
The Global Error channel can also be transmitted via CAN to a display device
and used to show an alarm message and activate an alarm light.
Maximum Current for Typical Output Devices
Lamps

Tungsten Lamps
Typically used for tail lights, indicator lights and general lighting.
Tungsten lamps draw additional current during turn on. Typically this
peaks at about 5 times the steady state current and dies out in about 0.1
second. The PDM will largely ignore this due to the Output Load filtering.

Halogen Lamps
Halogen lamps are commonly used in headlights and are more efficient
than Tungsten lamps.
Halogen lamps have similar characteristics to Tungsten lamps.

Xenon (HID) Lamps
Xenon lamps are also used in headlights and are more efficient than
Tungsten and Halogen lamps.
Xenon lamps have a long duration inrush current that peaks at about 4
times the steady state current. The inrush current decays over a period of
about 10 seconds. This puts a high load on the PDM output during start-
up.
To avoid Over-Current Shutdown during start-up it may be necessary to
set a higher Maximum Current than normal particularly if the battery
voltage is low.
For example, a Xenon lamp with a steady state current of 3 ampere may
need a Maximum Current setting of 6 to 8 ampere. The wire should also
be rated at this current.
Unlike other lamps, Xenon lamps draw more current as the battery voltage
decreases. At 10 volt the lamp will draw 40% more current than at 14 volt.
For example a lamp that draws 3 ampere at 14 volt will draw 4.2 ampere at
10 volt. This must be allowed for when setting the Maximum Current.
To ensure that the Maximum Current is set appropriately, check that the
Output Load value stays safely below 100% during turn on when the
battery is at 12 volt (not charging).