Blown inverter (1 Viewer)

[Alisonron2017]

hi looking for help please
We brought a autocruise startrail 2008 at the end of 2016 so not used it much yet but my husband pressed the inverter switch to turn it on while we were hooked up to power point and blew the inverter sadly we couldn't get the same inverter so brought one very close to it but he tested it and got the air conditioning to work once off it but now can't get it to work and the sockets do not work in the motorhome from the inverter , very new to this so not sure if he has blown something else that we are missing

 

[suavecarve]

The inverter is fed from the leisure batteries presumably ?
I think the question more clever ppl are going to want to know is, what wattage is your air conditioning unit and the power of your inverter is what ?
One they are known then dependant upon the answers, are your batteries flat ?

 

[Alisonron2017]

The inverter is 2000w not sure of the wattage of the air conditioner but the inverter that blew was 1600 and that was running it fine , the leisure batteries do run the inverter and are fully charged

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[MikeD]

The air con in my Autotrail used to pull around 6 amps on 240v EHU.

 

[PhilandMena]

I assume your Inverter is wired to your leisure batteries (They all are to the best of my knowledge). So, when you switch on your inverter it will take a little power from you LB just to switch on. When you connect appliances to your inverter much more power will be taken from your leisure batteries. The amount and type of appliances you can use with an inverter will depend on a number of different aspects these being. 1. The total amount of power available in your battery bank (50% of your total should be your limit).
2. The type and size of the Inverter, Pure Sign Wave (if your charging things like Lap tops toothbrushes etc)
3. The amount of power taken up by your appliances. So, you need to do some maths to be on the safe side. Understand the wattage that is being used by your appliances then convert this to amps and deduct from your battery bank.

There are others on here who have more knowledge than me.

A question for you to help with my understanding of your problem. Why, if on mains hook up do you switch your inverter on ? Isn't your air condition hard wired into the 240V system or a plug that you simply plug into a 240 V socket ?
Anyway, it looks like you have blown a fuse and this is why there is no power at sockets. If this is the case your inverter is almost certainly being overloaded.

 

[PhilandMena]

The inverter is 2000w not sure of the wattage of the air conditioner but the inverter that blew was 1600 and that was running it fine , the leisure batteries do run the inverter and are fully charged

I suspect after reading this again your Air conditioning unit has now destroyed both Inverters ? You need to establish how much power your air conditioning unit is drawing and especially when it peaks !

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[Jim]

Should I overload my inverter it has a small switch that pops out and isolates it, are you sure your's doesn't?

 

[iceclimber]

Poor design if the inverters 'blow'. Usually, if you try to pull too much power from an inverter they should simply trip out on overload ?

Based on MikeD's comment of ".....6 amps on 240v EHU". Then if not on EHU and the Air con is started .... i.e. fed by the inverter (am surprised the wiring arrangement would allow such ?) Then I think you'd be pulling around 120 amps from the batteries ? If that was the case i'd imagine some main battery fuse somewhere should be blowing ?

 

[hilldweller]

my husband pressed the inverter switch to turn it on while we were hooked up to power point and blew the inverter

It says to me that a close relative of Minni Mouse wired up some auto-changeover relay system, badly. For your own safety you need to get a decent sparkes to look at it. You husband did nothing wrong, hitting that switch should not have blown anything.

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[eddie]

It says to me that a close relative of Minni Mouse wired up some auto-changeover relay system, badly. For your own safety you need to get a decent sparkes to look at it. You husband did nothing wrong, hitting that switch should not have blown anything.

100% Agree. I leave my inverter on when I am plugged into the mains to ensure that the Six Nations is still recorded should the mains be unplugged. It is a fundamental safety concern when looking at installing such equipment.

Who installed the inverter? Contact them and ask if there is any additional switching you have forgotten about? For example you should have an additional RCD "after" the inverter, "before" the 13 amp sockets in addition to the RCD/MCB's fitted by the motorhome coverter

 

[PhilandMena]

Then I think you'd be pulling around 120 amps from the batteries ? If that was the case i'd imagine some main battery fuse somewhere should be blowing ?

Can you explain this to me as I do understand these sums or how you arrive at it. Thanks in advance.

 

[MikeD]

I am not an electrician but I am sure someone who is will be replying soon.

But if you convert 12v to 240v you have a 20x multiplier

so it 6 amps (from the inverter) x 20 equals 120 amp per hour from your leisure battery.

Your 2000w inverter divided by the 240v equals around 8 amps output. If running full output it would be approx. 160 amp hours from the battery.

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[funflair]

Can you explain this to me as I do understand these sums or how you arrive at it. Thanks in advance.

Rule of thumb, battery has to deliver 20 times the amps to provide 240 volts, or was that not the question.

Martin

 

[hilldweller]

Then I think you'd be pulling around 120 amps from the batteries ?

The inverter should be wired direct to a battery via a fuse big enough for the job. BUT 120A would discharge a single average battery in maybe 10 minutes. It's not viable to run aircon off the average MH leisure batteries. Of course she could have ten of them under the seat.

 

[Alisonron2017]

Thank you everyone for your help and advice , to answer a couple of questions asked above ... the new inverter has a pop out switch should it be over loaded but the old one dose not , there are 2 large leisure batteries fitted. I will show my husband what has been said but he is booking it in for a full electrics check up for the best and safety of our little camper . Thank you again

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[MikeD]

If you are a member of the forum you get a "members" discount at Dave Newell in Shropshire. He advertises on the RH side of the screen.

Eddie Vanbitz in Somerset also gives a members discount.

Both would come highly recommended by members on here.

 

[wigster]

Ive got an old motor home. The person that bought it from new , bless him or her, wanted it with air con. Because it had air con the van has a built in generator to power it when off grid .
From the paperwork i have with the van that was why the genny was fitted. I hardly ever use the air con or genny .
I cant see how an inverter would be of any use running an air con unit for any length of time. Maybe your air con is for use when on hook up?

 

[gus-lopez]

&

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[Bart]

is your replacement inverter a "pure sine inverter " or a "modified inveter"
Do you have a link for it?

 

[two]

There should be a big fuse on the thick wire coming from the battery bank to your inverter. It could be that the new inverter, drawing more current, has blown that fuse. It may have only been 100A and you'll now need 200A.

 

[pappajohn]

After reading the opening thread again.....
You CANNOT run an inverter AND mains at the SAME TIME feeding only the vans original sockets.
I suspect whoever wired the inverter didn't include any kind of switchover device so the mains and inverter had a fight and the mains won.

Technical.......

Mains voltage, regardless of hook up or national grid, works on a frequency of 50Hz meaning the voltage changes from + to - and back again 50 times per second.
If both supplies connected at the same time the inverter could be in the + phase of the cycle and hook up in the - phase at the same time and apart from anything plugged in not working the difference in phases will destroy the electronics of the inverter.
To my knowledge it isn't possible to exactly match the cycle of two independent supplies.

Your van May or May not have a change over switch but needs exploring.
A change over switch turns off one type of supply while at the same time switching on the other type.

If it has one It may be a manual switch, hidden away somewhere, or an automatic switch which isn't working.
My thoughts it was wired by someone who ONLY turned on the inverter in the complete absence of mains power....wild camping etc...to save the cost and wiring of a changeover switch.
Very poor practice.

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[Camping Gaza]

What he said above...betcha that's it!

 

[autorouter]

To my knowledge it isn't possible to exactly match the cycle of two independent supplies.

It is perfectly possible if designed correctly, but it's not common in motorhomes. My 4 kilowatt solar rig on the house roof feeds an inverter that's synchronised to the national grid and feeds power into it.

Some vehicle inverters, like the Victron type, will synchronise to the mains, and even have the ability to boost the mains amperage from low amp hookups for short times by drawing on the leisure battery power.

You're quite right about the majority of inverters, though. Worst case scenario is 700 volts difference (230 volts is an average, but mains voltage routinely peaks at 350 volts).

Maybe the old inverter was synchronised, but the new one isn't. Just a thought... without Make and model information it's impossible to tell.

 

[138go]

After reading the opening thread again.....
You CANNOT run an inverter AND mains at the SAME TIME feeding only the vans original sockets.
I suspect whoever wired the inverter didn't include any kind of switchover device so the mains and inverter had a fight and the mains won.

Some of the newer inverters can sense if the power is on and switch themselves off. The inverter should have [ 240v In ] and [ 240v Out ] as well as [ 12v In ]. Anything else and you need separate sockets. Don't know how you expect to run Air Con from leisure batteries they use a tremendous amount of power. Bit like a very large fridge .. Virtually impossible.

Air con will use about 1kw so if your air con is 240v then it's about 4amps. To get 4amps from an inverter you are going to need about 80+ amps. Inverters are not efficient unless they are run at the correct wattage. If you use a 2000w inverter then you are only using 50% of its capacity and it will be far less efficient. All that means is the inverter is using the power to provide 2000w you are just not using it. Works out at 160 amps. So your 2000w inverter will be using somewhere between 80 and 160 amps.

As others have said .. I wonder how it was wired .. I do hope you have not blown the main control board or your new inverter.

When I wired my inverter a 300w Sine Wave unit it is connected to two separate 13 amp sockets. One in the front and one in the back. Gives out just the right amount of power for SWMBO's electric blanket.

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