NO guarantee as to the accuracy of these values is given.
And they should be checked against some other source.
Where ever possible the transformer should be mounted
near the light fitting, BUT not within 9 inches to protect the transformer from heat
damage
and to reduce the cable size required from the transformer to the light
fitting.
When wiring 12v
fittings either single or together, it must be remembered that lower
voltage means higher current, ( e.g. 1 x 50W 12v lamp alone requires
4.2 AMPS ).
Therefore, the
conductor size of the cable between the transformer and the fitting is
larger than that used in 240v lighting circuits.
Due to the
possibility of voltage drop, the correct choice of cable is vital.
Undervolting by more than 0.6v reduces the efficiency, affects the
colour of the light and may affect the lamp life.
The calculator above will help you make the correct
choice of cable.
DO NOT lay under or encase the cable or transformer
with roof insulation
Supplying
more than one lamp from a single transformer can result in significant
volt drop between lamps if wired in parallel, causing non uni-form
illumination across the run of lamps. To overcome this we recommend using
the IB FS020 fused splitter or a multi-outlet transformer.
Each lamp supply is
protected by an anti-surge fuse which prevents the transformer output
from being dragged down in the event of a short circuit in any one of the
fittings
Note: The actual cable size and
runs required to connect several lamps to the same transformer output
must be equal to or greater than total load of the run
Allowances MUST be made for operating
temperatures outside the above,
for correction factors refer to the full IEE 16th edition regulations for
tables.