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Specialised Power systems for Service Van, HGV truck, Motorhome, Caravan, Camper van, Ambulance, Catering Trailer,4x4,Utility Vehicles, Canal boats, Marine .
Mobile installation service available in
Telford & Shrewsbury, Shropshire areas.
 
Mobile onboard power at UK mains voltage 240 volts AC is required on many types of vehicles including
Leisure vehicles with living accomodation such as Motor home, Caravan, Camper van.
Vehicle Conversions where a panel van , 4x4 or truck has been modified for specialist utility service use and
may operate 240 volt or 110 volts powered equipment.
Exhibition display vehicles , library vans, etc which have 240v interior lighting and services,
Ambulances with 240 volt medical equipment and lighting.Mobile Shops and libraries where 240v power is required to operate a computer for stock control or invoicing, and extra display lighting is required.
Interior lighting may be 12v or 240v
Marine craft eg, Sailing yacht , motor boat, canal barge, with living accomodation.
Vehicle Charging System Voltage
Automotive battery systems recharged by an alternator
operate at either 12 volts DC (charging voltage approx 13v to 14.8v) or 24 volts
DC (charging voltage 28v)
UK domestic appliances operate at 240 volts AC mains .
Portable tools for site work ,eg drills, grinders,etc may operate at 110 volts.
Mains Voltage
Various systems exist for supplying 110v or 240 volt AC onboard power depending on application and requirement.
A suitable power source can be supplied from a mains "hookup", dedicated generator, or conversion of existing vehicle electrical power to the required current and voltage types using an "Inverter"
Inverters
An Inverter converts the the vehicle's conventional 12 or 24 volt DC supply to 110 or 240 volts AC.
The Inverter output may be Pure Sine Wave (more expensive type) or Modified Sine Wave (cheaper type).
Inverter units may be linked to achieve larger power output or a dynamic inverter system used.
A "leisure" or "domestic" (deep cycle) battery bank is often used as the 12v or 24v power source to supply the inverter system.
Inverters are often used in vans to convert 12 volts dc to 240
volts ac
12 volt DC to AC Inverters can draw large amounts of current
from vehicle batteries and depending on type may require heavy duty battery
cable to carry the power supply
Leisure Battery Charging
from vehicle power source
The vehicle's single alternator may be used to recharge both starter battery and leisure battery
by use of a split charge relay or battery management system which allows switching between battery banks.
The vehicle can be fitted with more than one alternator, for example no.1 alternator to charge the starter battery and no.2 alternator to charge the leisure battery or both linked to provide greater output capacity.
Split Charge Systems for Seperate Battery Banks
A split charge system separates vehicle starter and leisure battery until the vehicle engine
has started then connects to link both battery banks.
This prevents the inverter system discharging starter and leisure batteries to a level at which starter motor operation fails
rendering the vehicle immobile.
Split charging
system using a heavy duty voltage sensitive relay
Additional batteries may be linked
via cable to the starter battery by use of heavy duty
voltage sensitive solenoid relay (VSR).
Use of a VSR allows priority
charging of starter battery which must reach a preset voltage level before the
leisure battery is connected to the charging system only when the engine is
running and alternator charging. This reduces the risk of discharging the
starter battery to a level at which the vehicle is immobilised.
Secondary
battery charging using splitter diodes
This method uses a
heavy duty diode fitted in the link wire between starter battery and
leisure battery pack. The diode acts as a one way valve to allow current to pass
from the starter battery to the leisure battery whilst the starter battery is at
a higher voltage potential than the leisure battery allowing rechargeing. The
diode blocks current from being drawn from the leisure battery when the starter
motor is operated to protect cabling. This system has a disadvantage of power
losses due to diode characteristics.
Secondary battery
charging using DC to DC battery charger
This
preferred method uses a special battery charger to regulate charging voltage and
current between battery banks. Use of a DC to Dc battery charger can provide a
method of charging auxiliary 12 volt batteries from a vehicle with 24 volt
charging system.
Secondary
battery used to provide cold start assistance
Provided the
connecting cables and relays are specified to carry high starter motor current
draw the secondary battery may be linked via switchgear to the starter battery
to improve cold starting.
An effect of reduced starter battery voltage results in an increased current draw as the starter motor operates (see Ohms law ref : Power(Watts)=Current(I) x Voltage(v) ) causing premature failure of starter motor or cabling.
Alternative energy sources for leisure battery charging
Alternative energy sources may be used to recharge leisure batteries such as use of solar panel battery charger or wind
powered generator (sometimes used on marine installation) if sufficient capacity can be achieved.
Leisure battery charging from mains hookup
When the vehicle is parked where a site hookup (via BS4343 connector) is available a battery charger may be used to recharge the leisure battery bank
whilst the vehicle is stationary.
Generators
110 volt or 240v power can also be achieved by a vehicle powered generator system, or by a stand alone portable
generator. Vehicle powered generators may be run from the vehicle engine
or via a power take off facility on the transmission driveline.
415 volt Three phase power for heavy duty specialist & industrial applications may be provided by a larger diesel powered generator.
Auxilliary power systems may be integrated so that the inverter system and generator systems work together during periods
of peak demand.
Safety & Circuit Protection
240 volts ac power circuits must incorporate the following: Residual Current Device ( RCD ) with adequate earth bonding to provide protection from electric shock
Overload protection
Short circuit protection
Please note ! Automotive electrical cable intended for use on low voltage systems is not suitable for use on systems operating at mains voltages (Why? Higher voltage potential requires better cable insulation) .
Electrical Installations in caravans and motor homes should comply with section 608-** of the IEE
16th edition Wiring Regulations. " superceded by the 17th edition IEE Wiring regulations which apply after July 2008.
Periodic Inspection preferably not less than once every three years or more frequently if the vehicle is used for more
than normal mileage.
For such vehicles , the caravan electrical installation and supply cable should be tested and a report
on their condition obtained as prescribed in BS7671 (formely the Regulations for Electrical Installations) published by the
Institution of Electrical Engineers.
Reducing Power Consumption
Consider using energy saving low power consumption devices such as LED Lighting when specifying your vehicle installation.
This will mean the power requirement from the vehicle batteries is reduced therefore taking longer to discharge,
and allowing specification of smaller batteries thus saving weight and fuel.
LED lights are available for both interior lighting and exterior
lighting.
Voltage Converter
Onboard electrical equipment may operate at different voltage levels to the existing vehicle power supply requiring use of a voltage converter.
24 volts Vehicle power to 12 v equipment
Commercial vehicle electrics operating at between 24v and 28 volts are a typical example. The HGV Driver may require a 12 volt car audio system fitted.
A common method used by the driver can be to run a long cable from one of the series wired 12v batteries, along the chassis & into the vehicle cab often with the potential to discharge the truck batteries leaving the vehicle unable to be started or the cable becoming damaged when the truck cab is tilted.
The professional installation would make use of a voltage converter (or "Volttage Dropper ") fitted inside the cab of the truck & using the normal 24v supply input reduced to a suitable 12 volts output for the audio equipment.
12 volts to 24 v converter
Voltage Converter units are available which can step up the vehicle's 12 volt power supply to enable use of 24 volt auxilliary equipment
Transformer
Mains Power for Vehicle , Low Voltage Applications
Power transformers are available to reduce voltage of
mains electricity to operate 12v or 24 volt systems.
The typical example is a commercial vehicle used for multi drop distribution.
During delivery operation the vehicle alternator recharges the auxilliary battery bank used for tail lift operation as the vehicle travels between delivery sites. However, whilst the vehicle is being loaded the tail lift may be in constant use with the vehicle engine off , causing the auxilliary batteries to become discharged resulting in slow operation of the tail lift equipment, and the chance that the engine may not be started.
The answer to this problem is to use a special mains powered transformer that reduces the mains voltage level and type to enable operation of the tail lift equipment without the vehicle engine running, avoiding the safety issue of engine operation on unattended vehicles.
We will be pleased to help with your vehicle onboard power enquiries by email.
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