Electricity & Safety


Consider 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 flooding.
● 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 timer’s contacts unless relay switching is used.
● 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

Cost of power per day = Cost of power per kilowatt* x Total kilowatts** x daily duration.

e.g. If 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)

*Refer to your last power bill. **1,000 watt = 1 kilowatt (kW)