wet sunday electrical question.

[narooma]

What ,if any, are the consequences of putting a 24v supply to a 12v light fitting with a 24v bulb in it? Or are 24v bulbs different in design and not capable of fixing in a unit designed for 12v.
(no bulbs here to check that)

 

[MasterofHera]

12 volt and 24 volt bulbs are very often interchangeable BUT the wiring may not be up to the job.

 

[narooma]

Thanks H-M. My concern was regarding the integrity of the fitting. 24v units are in shorter supply than 12v ones so better choice

 

[dean1973]

there are more amps with 12v than 24v so it should be safer with 24 volts just looking myself for some bulk head lights
as in nav lights you just cange the bulb

 

[halcyon]

For the same wattage, the current with a 24 volt bulb will half that of a 12 volt bulb.

Brian

 

[bobgoode]

No worries at all, but there might be problems if you applied 12V to a 24 v fitting, the wires might get a tad hot. As has been stated 24 watt bulb at 12 volts takes a current of 2 amps but only 1 amp at 24 volts. The higher voltage will not pose any problems with the insulation.

 

[VicS]

Generally there is no problem with the fittings. They use the same range of sizes, unless you are unlucky enough to have a non standard one. Dual filament bulbs and those for special applications may have offset pins.

No problems with the wiring. As said already the current for a 24volt bulb will be half that for the same wattage 12volt bulb

 

[pcatterall]

Confused.... 24v are in shorter supply than 12 v so better choice?? or have I missread this?? ( as usual!!)

 

[jwrhind]

If the maximum wattage of the bulb you fit exceeds the rating of the fitting, you may find that the extra heat damages the fitting / reduces bulb life.

So, to state the obvious, you should limit the bulb wattage to no more than that of the fitting. The current for a 24V bulb is only half that for a 12V bulb of the same power rating.

 

[sarabande]

Check out the lorry / truck sites. They have masses of 24v stuff.

 

[VicS]

[ QUOTE ]
Confused.... 24v are in shorter supply than 12 v so better choice?? or have I missread this

[/ QUOTE ] Probably just that light fittings are supplied complete with a bulb so in only a small number of cases they are listed with either option but in the majority, because there is a much smaller demand for 24 volt, they are only offered with a 12volt one.

 

[wotayottie]

cant imagine it being that easy to get 24v bulbs

 

[Stoaty]

I have a 24 volt system. I have never had a problem with 24v bulbs. Every chandler stocks them.

 

[halcyon]

Is it the light units that are limited in 24 volt, thus buy 12 volt units and put 24 volt bulbs in.

Brian

 

[roger]

The 24v light fitting wattage rating has two aspects: the current through the contacts (less for 24 v) and the bulb dissipation. The bulb dissipation matters less if the bulb is in open air but must be followed for an enclosed bulb.

 

[narooma]

Thanks one and all. Will now source new 12v lamps and change bulbs to suit system.