Systems for use with Renewable Energy
Power & Distribution 2
Electrical Safety 2
This would generally be power from any form of generator or inverter system that produces 100V A.C or greater, typically 110V or 240V A.C. nominal (this also includes for our purposes any ripple free D.C voltage greater than 120V).
All A.C lines must have some form of adequate overload protection. This is often included in such items as inverters, but the cable itself must be considered if it’s power rating is less than the peak inverter power. Again, protection may be provided by a suitable fuse and fuseholder or a suitable M.C.B etc.
A suitable earth must be provided where A.C. lines are accessible to performers
or public, or when they are used in conjunction with exposed metal work or
any equipment that clearly requires earthing ( i.e. it has an earth wire).
This would be a copper-covered steel spike as sold by electrical wholesalers
for the purpose. All such lines must also be protected by a Residual Current
Device (R.C.D) to eliminate any risk of electrical shock.
All connections should be safe and adequately shrouded. Awareness of damp conditions is essential and waterproof fittings should be used in all outdoor areas. Ceeform type connectors as used on caravans and construction sites are particularly suitable.
Charging Systems:
Generally wind, solar or pedal power, with other potentials
being explored. All charging systems produce energy, but unlike battery stores,
they tend to produce a more finite energy
delivery, e.g. a small solar panel or wind charger output can be shorted quite
comfortably (a standard method of braking a wind generator, in fact!)
Larger systems can deliver enough energy to overheat or possibly burn out
a thin cable. Thin cables cause unacceptable energy losses anyway, so as long
as a suitable gauge wire is used this should not be a problem.
Where electrical dangers lie, is usually with output voltage. If not connected to a battery or a voltage regulator many charging systems can often produce high output voltages, windcharger outputs in particular can often reach potentially lethal voltages given a good wind. This also creates the possibility of electrical arcing on loose terminals or contacts (which could cause battery gases to ignite for example).
Cables and connections shall therefore be suitably rated and all connections secure. Insulation of cables and connectors shall be adequate for the circuit voltages that may occur (generally 240V A.C. rated cable is recommended on all wind chargers and unregulated pedal generators etc).
Cable Runs in General:
All cables should be positioned so as not to cause any hazards; no persons should be able to trip or catch themselves on them. When cables are placed in areas accessible to the public the cables themselves must also be protected from being damaged. A.C. power lines are best kept out of public reach, and if suspended they should be not less than 3.5 metres high (14ft). They should be clearly marked as ‘high voltage’. This is perhaps more important than usual, as many people do not associate such voltages with renewable energy sources! Buried cables of all types should be marked in areas that have a risk of other structures etc (including tents) being erected. Not to mention unexpected bonfires!
Suspended cables must be adequately supported by a separate strain wire or rope and all fixings must be secure. All connectors and connections must be safe and wired in accordance with standard practice. All cables must be suitably rated and insulated for their intended use.
Other Points:
All equipment in use should be fit for it’s purpose and be safe in use. Adequate space is required around lamps and light fittings to prevent overheating and possible combustion of fabrics etc., and lamps should not pose a glass hazard in the event of failure.
Connectors designed and sold for general use on electrical mains (e.g. 110 -240V A.C.) must not be used for low-voltage and/or D.C. systems.
Where more than one voltage is in use in the same venue, connectors for these voltages should not be interchangeable.
