the safety of electrical circuits at the design stage:
- Keep power devices (e.g. ballasts)
and junctions away from or above any potential water spillages and
- Determine whether the electrical
lines and connections can handle the current draw.
- Where multiple lamps are being lit
ensure to stagger start up times.
- High lamp current will cause burning
of the timerís contacts unless relay switching is
- Install a miniature circuit breaker (MCD)
and residual current device (RCD) as an overall safety measure. If there
is a faulty circuit these will cut the power supply (Fig 4.9).
Calculating electricity costs
power per day = Cost of power per kilowatt* x Total kilowatts** x daily
the cost of power is $0.10 per kW and there are 2 x 600W lamps (1.2kW)
alight for 12 hours per day, the daily cost of electricity is $1.44 (i.e.
$0.10 x 1.2kW x 12hrs)
to your last power bill. **1,000 watt = 1 kilowatt (kW)