Hi All

I have 2 inverters in the Caravan 300w and 600w, i have only used the smaller one a few times.

They are both located in the battery locker and only the smaller one is connected and turned off, unless needed.

To use it, i lift the seat to get to the battery and simply plug in a power board then plug in the Laptop or appliance i want to use.

How do others use it , do you have a wall mounted dedicated 240v plug connected to the inverter,

or can you plug in the caravan and use the caravan 240 plugs. I am just looking for a tidier way to do it.

Thanks Stewart 

Tony Bev wrote:

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Hi Stewart
I am not an electrician

I have a 300/600 watt (300 normal 600 peak), 12 volt DC to 240 volt AC Inverter

As I only use it to charge up my cordless drill, and cordless impact wrench batteries
(I have, just to make sure it can do so, charged my laptop, and phone, from this Inverter)
I just plug the Inverter into a ciggy type socket

The ciggy type socket, is connected direct to the house batteries, via a 10 amp fuse, at the battery

I keep the inverter, inside its original packing box, and packed away, in a cupboard, as I find that I seldom use it
I find that I can charge my laptop, phone, camera, rechargeable AA batteries, with the 12 volt ciggy socket system

My theory is, is that my Inverter would probably travel better, inside its packing box, than fixed to a wall/floor

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 A word of caution.

If you draw 300W from an inverter it will draw about 30A from the 12V system which is waaaaaay over the capacity of a cigarette lighter socket which is typically 10A.

Cheers,

Peter

Hi 

A couple of comments ! I have found ciggy sockets are unsatisfactory for serious use, and you need good quality ones you can lockin the plug or it just works out.  If you restrict them to just low currents they can be OK. BUT if they have a 10A fuse then that will limit them to 120W which is way less than 300W and indeed the startup current might blow the fuse turning it on.  

So hard wired close to the 12V battery will work best and if you need to move it a bit further then fit bigger heavier wires and some appropriate fuse for the max current and put it where you can access the switch easily.

As has been said an inverter produces 240V AC that will kill you just like at home, but it does not have any earth so not nearly as safe as at home if there is a faulty appliance! Remember that please. Double insulated items which are not fitted with an earth plug are safer.  My advice is to just use a single shorter 240V lead to a convenient place for a single item to be plugged into. 

Jaahn

I see there have been some posts while writing !      

Peter_n_Margaret wrote:

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Tony Bev wrote:

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Hi Stewart
I am not an electrician

I have a 300/600 watt (300 normal 600 peak), 12 volt DC to 240 volt AC Inverter

As I only use it to charge up my cordless drill, and cordless impact wrench batteries
(I have, just to make sure it can do so, charged my laptop, and phone, from this Inverter)
I just plug the Inverter into a ciggy type socket

The ciggy type socket, is connected direct to the house batteries, via a 10 amp fuse, at the battery

I keep the inverter, inside its original packing box, and packed away, in a cupboard, as I find that I seldom use it
I find that I can charge my laptop, phone, camera, rechargeable AA batteries, with the 12 volt ciggy socket system

My theory is, is that my Inverter would probably travel better, inside its packing box, than fixed to a wall/floor

---

 A word of caution.

If you draw 300W from an inverter it will draw about 30A from the 12V system which is waaaaaay over the capacity of a cigarette lighter socket which is typically 10A.

Cheers,

Peter

---

Thanks for that info Peter, I appreciate it

And it is also good, that someone will come along, and show any reasons, why something should be done, in a particular way
In this case, hard wire verses a ciggy plug socket, on an inverter capable of 300/600 watts

Not sure how many watts are being used, to charge up my cordless drill and impact wrench, batteries
I placed my el-cheapo clamp meter, on one 12 volt wire going into the inverter, and it was showing (from memory), below 5 amps
This tells me (for my situation), I can safely use the ciggy plug, and not have to hard wire the inverter

The inverter I purchased (el-cheapo) from eBay) came with 3 cords
1 with a male giggy plug
1 with battery clamps
1 with lugs to be hard wired onto the battery

I am a little reluctant, to hard wire this inverter, in case the vibrations it will receive from travelling, damage the internals

Just a reminder plug a RCD in the 240 output of the inverter then plug your equipment into that. Don't want anybody being electrocuted for one reason or another!

Whenarewethere wrote:

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Just a reminder plug a RCD in the 240 output of the inverter then plug your equipment into that. Don't want anybody being electrocuted for one reason or another!

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Sorry, but an RCD (Residual CURRENT Devise) will provide no protection for an inverter running more than one (non double earthed) appliance which (like a generator) is a floating supply without an effective earth.

For effective protection you need an RVD (Residual VOLTAGE Devise).

Cheers,

Peter

Hi all; I have had a pure sine wave inverter mounted under my bed and right next to the house battery and when i wanted to use the inverter, one would have to lift the bed and turn the inverter on at the built in switch. What i have now done is to install a small push on switch ( has a built in led to show it is in the "on" position. This switch controls a 12 volt 30 Amp relay and the relay switches the 12 volts to the inverter. No more lifting beds just to turn the inverter on or off. I only use the inverter for my electric shaver and the odd time when i need to use my laptop computer or charge the computer's battery.

Peter_n_Margaret wrote:

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Whenarewethere wrote:

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Just a reminder plug a RCD in the 240 output of the inverter then plug your equipment into that. Don't want anybody being electrocuted for one reason or another!

---

Sorry, but an RCD (Residual CURRENT Devise) will provide no protection for an inverter running more than one (non double earthed) appliance which (like a generator) is a floating supply without an effective earth.

For effective protection you need an RVD (Residual VOLTAGE Devise).

Cheers,

Peter

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 I see what you mean. My UPS being earthed, then in this situation a RCD works.

Stewart wrote:

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Hi
So how to do people get on in the annex, when on a powered site

where i can have a power board and 2 appliances plugged in, a portable waeco fridge and maybe washing machine, or a cooker

Is this no good either, now im getting concerned

Thanks stew

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 I am not an electrician either Stew but my personal view is that what you suggest is probably reasonably safe, just not in accordance with all of the rules.

You do have protection via the RCD at the caravan inlet and that would be effective. You don't have double pole switching in the power board, but the power point that the power board is plugged into in the van is double pole.

Cheers,

Peter

Erad that is not correct  an RCD detects current flow to earth.

Alan

Erad I think you are correct . With a short through your body between active and neutral there is no difference in current so you are dead and the RCD won"t know. Hence an RVD is essential with inverters/generators plugged into your vans socket.

Alan

Frank (KFT):
Thank you for your comment. I agree that if a person creates a fault between the high voltage (active) and low voltage (neutral), the RCD will not sense a fault and therefore will not trip. However, in nearly all cases the low voltage will not be very high (certainly not enough to be lethal). Certainly a fault could occur with a double insulated device when a person completes the circuit to the low voltage. But this would happen with a regular power supply anyway. If a person contacts a high voltage source and completes a circuit to earth (gets a shock), not all the current will return to the generator and therefore there will be a difference between the high and low voltage lines and the RCD should trip. What voltage does a RVD trip at?

-- Edited by erad on Friday 17th of April 2020 07:52:23 AM

Hi 

Just a comment about the voltage of active and neutral. By design in our excellent house power distribution system, the neutral line is held to ground voltage by the link to ground at all meter boxes and transformers. That is the inbuilt safety of our power distribution system. So fair to say that the active voltage varies up and down from earth voltage (using one phase).

However an inverter (and generator) is a floating system and produces alternating voltage not linked to any earth (or neutral) to hold the voltages to normal limits. So there is no real neutral and active but just AC up and AC down, that voltage could be at any potential and probably drifts around up and down. That might give you some cause for thought about them and safety. 

Jaahn      

I remember when I first started off in my caravan that someone told me about inverters and their use when mains power was not available. I wandered off to an auto shop where the person there knew even less about them than I did. He sold me a 1000w inverter that had battery clips on the end of the leads. I asked him if I could use this in the 12 volt socket if I attached a lead with a socket plug on the end. "No worries" he assured me and off I went to charge up the laptop. I plugged the beast in to the socket and promptly blew the 10amp fuses to bits.

I called an auto electrician friend of mine who informed me that I was a complete idiot and that it should only ever be attached directly to the battery with the clips provided and that if it was to be attached to a socket, then that would have been provided. Well you live and learn and the inverter was then placed into a cupboard and has not been used since.

Undaunted by this minor mishap and after reading one of Chief Doug's enlightening posts, I went to a different place and purchased one of those small "coke can" type of inverter. This was plugged into the 12 volt socket and the lead attached to the computer whilst I stood well back waiting to see what disaster would unfold. Surprisingly, or at least to me, all went well. The battery hardly noticed the inverter bludging off it and the laptop kept charging as I was using it. 

The moral of the story, less is best and listen to Chief Doug!

Welcome to the forum Stewart. The inverter I purchased is about 150 watts from memory. It will charge the phone and the laptop easily. I turn the computer on and plug it into the inverter and can spend as much time as I like as it more than covers any drain on the battery. In fact, the battery is fully charged after about 30 mins even though I have been using the computer during all the charging time. The other good thing is that I can plug it into the cigarette lighter in the tug and charge up the laptop whilst driving along.

I haven't used it to operate anything else so don't really know what its limits are.

From memory it cost about $50 from an electrical store. It look like a coke can only smaller.

I hope that helps.