Specifications

Electrical systems
44
Electrical systems
45
Note: Never use a mains supply lead whilst
coiled. Always uncoil the full length before
connecting to the supply and remember to
protect the cable from traffic.
MAINS UNIT
This acts as the main switch for the motorhome
allowing isolation of all circuits. It forms part of
the Power System along with the Transformer/
Charger Unit (if fitted).
The mains unit replaces the conventional
fusebox. Similar, but larger ones are often fitted
in new houses.
Theunitgivesbothoverload(MCBs)andearth
leakageprotection(RCD)fortheelectrical
supply in your motorhome.
For normal operation all switches on the unit
needtobeintheONposition.Thesmall
switchesontheunitareknownasMCBs
(miniature circuit breakers).
These take the place of the conventional fuse
but are more convenient.
Note:Havingtoomanyappliancesswitched
onatthesametimewilltriptheMCBs.Thisis
a safety measure. (For appliance ratings, see
mains consumption).
IntheeventofafaulttheMCB‘trips’ie
automatically moves to the OFF position.
AftereliminationofthefaulttheMCBcanbe
re-setbyswitchingtotheONposition,(against
the spring pressure in an upwards direction).
If an earth fault develops or a person touches a
live piece of equipment the leakage of current
toearthshouldimmediatelyoperatetheRCD
(residual current device) and ‘trip’ the main
switch, to the OFF position.
This switch is only re-settable after elimination
of the fault. To re-set, operate the switch as
forMCBs.
PeriodicallytheRCDshouldbecheckedby
operating the test button marked ‘T’. The unit
should immediately switch to the OFF position.
If the unit does not switch off then a qualified
electrician should be consulted.
If the unit does switch off, the test is complete
and the switch can be re-set restoring the
supply back to normal.
Add together the current ratings for each
electrical appliance you wish to use
simultaneously and ensure the total does not
exceedtherelativeMCBratings.Youwillndthe
table on page 52 a useful guide to typical values.
Depending upon model, switches on the front
of the consumer unit can be used to switch off
230v supplies to the charger, or, space heater,
water heater and charger.
Care is needed if a Truma Ultrastore water
heater is fitted. If a 230v supply is introduced
to the water heater when that water heater
is empty, there is a possibility that the 230v
element within the appliance will overheat and
the water heater will go into a failsafe mode.
The 230v supply to the Ultrastore will then need
to be switched off, and the element be allowed
to cool, before the Ultrastore will function again.
We recommend that the switch marked water
heater is left in the off position unless water is
present in the water heater.
12V POWER SYSTEM
Note:Theconnectionofthebatterycharger
to the mains supply is in accordance with the
RegulationsforElectricalInstallations16th
Edition(IEEWiringRegulations)BS7671:1992.
MainsUnit
MOTORHOME BATTERY
It is recommended that a good quality leisure
battery is always in circuit when the system is
in use.
A deep cycling rechargeable heavy duty 12v
battery should be used to provide power
for lights and other electrical appliances. A
proprietary brand leisure battery with a minimum
85amp - 110 amp capacity is recommended.
Note:85amp-110ampbatteriesandabove
should be checked dimensionally before
purchasing, to ensure fitment within the battery
compartment, as brands vary in size.
It should be remembered that batteries suitable
for the electrical demands of a motorhome
differ in design from those for use with a car,
and whilst the system may operate with a car
battery it is strongly recommended that only a
rechargeable leisure type battery, maintained in
good condition is used. The battery should be
kept topped up at all times.
The battery should be positioned in its
compartment, which is vented to the outside,
and be properly secured before travelling.
WARNING: When connecting the
battery, ensure that the correct polarity
is observed (black is negative and red
is positive) and that the terminals are
securely fastened.
Under normal circumstances it should not be
necessary to remove the battery other than for
routine inspection of terminals and ‘topping up’.
WARNING: Explosive gases may be
present at the battery. Take care to
prevent flames and sparks in the vicinity.
Your motorhome has been fitted with an in-line
fuse between the battery terminal and strip
connector. It is recommended that the fuse
rating fitted in this location does not exceed
40 amps.
WARNING: Switch off all appliances and
lamps before connecting or disconnecting
the battery.
Smoking is prohibited around the
battery compartment.
To preserve the life of your leisure battery and
charger please observe the following:
i) Do not leave all 12v lights powered at the
same time as this will drain your leisure
battery more rapidly.
ii) If all 12v lights must be powered together,
ensure the battery is ‘in-circuit’ and that the
battery charger is turned on.
iii) For optimum performance use the
transformer/charger unit with a leisure
battery attached.
Please note the auxiliary battery supplied with
your motorhome may not be fully charged and
should be charged for a minimum of 24 hours
before use.
FAULT FINDING
1. Mains supply
If mains supply is not available when mains
switchandMCBsareswitchedon,check
supply at site distribution and/or mains lead
and connections.
2. Earth faults or MCB tripped
SeeRCD/MCDSection.
3. Charger switch fails to illuminate
CheckmainssupplyasforNo.1and2.
4. Battery discharged or not charging with
charger on
Check battery terminals.
5. 12V distribution circuit failure
Check and replace relevant DC output fuse
as required.
6. Consult the manufacturers regarding any
further difficulties, in particular those related
to mains voltage section.
7. There are no user-serviceable or
replacement parts in the consumer unit. All
service of this nature should be referred to
the manufacturers.