Inverter Question?

[Dougal]

I have a Sterling 1200watt (peak) inverter with a single 230v outlet. Obviously, its not designed to power the boats main circuit, but wondered if there's a reasonably safe way to hook it into the boats 230v circuit? Is it totally out of the question to simply run a male to male cable from inverter to shore power inlet?

I have an outside shore power socket and mains protected distribution box.

 

[pvb]

Is it totally out of the question to simply run a male to male cable from inverter to shore power inlet?

Your shore power socket must be a male, so the cable you propose would have to be a male to female. Yes, that would work.

 

[GrahamM376]

I have a Sterling 1200watt (peak) inverter with a single 230v outlet. Obviously, its not designed to power the boats main circuit, but wondered if there's a reasonably safe way to hook it into the boats 230v circuit? Is it totally out of the question to simply run a male to male cable from inverter to shore power inlet?

I have an outside shore power socket and mains protected distribution box.

Safest way is to install a double pole 3 way switch ( 1, off, 2) and wire the inverter and shore power into that between the deck socket and the RCD. I use one of these - http://www.marathonleisure.co.uk/product.php?xProd=200486

Switching this way prevents the inverter and shore power being on at the same time and also stops the inverter feeding the deck socket which could spoil someone's day.

 

[superheat6k]

Double ended plugs are an accident waiting happen. If you feed in through the shore power inlet point via a female on the lead, then there is no chance of shore power being connected at the same time.

However, 1200 w peak will likely only be around 900w continuous and even this will severely kick your batteries. A typical kettle is around 1,500 W, so apart from a few lamps you won't run very much.

 

[JVL]

Double ended male is what I have , complete with a big label with an anchor pictured on it. Works for me but I feel sure somebody will tell me I'm bound for hell.

John

 

[Dougal]

My electric hot water element is only 600watt and with direct engine cooling, I don't have hot water via that. I would normally only run the inverter with the engine running while motoring, so using shore power at the same time would require a lead of......;-))))

 

[JVL]

My electric hot water element is only 600watt and with direct engine cooling, I don't have hot water via that. I would normally only run the inverter with the engine running while motoring, so using shore power at the same time would require a lead of......;-))))

Hence my anchor picture on me dodgy lead lol

John

 

[single]

I can't see what the safety issue is? Its as simple as plugging the 13a 3 pin plug into the inverter and the other end into you boat shorepower 'in' socket.

View attachment 51370

 

[superheat6k]

600W would require a local current draw of 50 amps from the 12v DC system, but with cable and inverter losses closer to 60 amps. To keep pace with this you would need an alternator capable of at least 70 amps output, bearing in mind any other equipment drawing from the same alternator supply. This will also require a full HP of power from the engine. Not a problem if you have plenty of them, but on a smaller engine say <20 HP a noticeable drag, especially at lower speed.

The cabling on the 12 v dc supply to the inverter will also need to handle 60 amps continuous, and for the peak load >100 amps - e.g. at least 16mm2 for a short run increasing to 25mm2 if the run is greater than say 6 or 7 m loop length.

As for a double ended plug, unless you are very comfortable with electricity I would not do this. The problem with electricity is it is perfectly safe until you forget it is dangerous. In your situation there is also the possibility of having the inverter plugged in at the same time the shore power is connected. If you run the inverter via the shore power receptacle this cannot happen.

 

[VicMallows]

OP asked a very simple question: " Is it totally out of the question to simply run a male to male cable from inverter to shore power inlet?"

I suspect he may mean connecting the outlet from the inverter to a standard 13A Plug.... which then plugs into an existing outlet on the boats AC circuit. Certainly not recommended practice, but it will work, and if you understand the risks it is up to you.

 

[superheat6k]

Now I appreciate we live in a risk averse world, with routine work requirement for Risk Assessment and Method Statements for the most innocuous of tasks. In amongst these tasks are some practices and potential situations which are genuinely lethal for which proper and diligent safety measures are required. OK so recreational boating sits outside the sometimes onerous practices required for safety in the workplace, but I utterly fail to understand that anyone would promote proudly that using a double ended male plugged lead is somehow OK. This is not bravado, it is IMHO stupidity.

This is particularly the case when some one else unplugs this lead ignorant of what he or she is then holding.

If just one person reading this thread does not create for themselves or perhaps stops using a double ended male male lead then I make no apologies to those who think it is OK to do so, and whom my response may annoy.

As the OP needs to ask this question suggests he does not understand the full implications of doing this from a safety perspective.

 

[AuntyRinum]

I have a Sterling 1200watt (peak) inverter with a single 230v outlet. Obviously, its not designed to power the boats main circuit......

I can't agree with that. I have a Sterling 1800watt inverter which powers the boat's mains circuit when it doesn't have shore power. The only appliances which I can't use with it are the electric kettle and washing machine. Apart from those it provides 240v power, when required, for a fridge, a freezer, HD TV, Humax, laptop, printer, dvd player, and power tools, sometimes all at the same time. Although, I have to say, I try not to use everything at the same time; the batteries will only hold up for about 4 hours if I do.

 

[pvb]

Now I appreciate we live in a risk averse world, with routine work requirement for Risk Assessment and Method Statements for the most innocuous of tasks. In amongst these tasks are some practices and potential situations which are genuinely lethal for which proper and diligent safety measures are required. OK so recreational boating sits outside the sometimes onerous practices required for safety in the workplace, but I utterly fail to understand that anyone would promote proudly that using a double ended male plugged lead is somehow OK. This is not bravado, it is IMHO stupidity.

This is particularly the case when some one else unplugs this lead ignorant of what he or she is then holding.

If just one person reading this thread does not create for themselves or perhaps stops using a double ended male male lead then I make no apologies to those who think it is OK to do so, and whom my response may annoy.

As the OP needs to ask this question suggests he does not understand the full implications of doing this from a safety perspective.

I think that's a bit extreme, the OP was simply confused. He was asking about having a cable to plug into the 13A socket on his inverter, with the other end plugged into the shore power inlet. He wrongly described it as a "male to male", when it obviously has to be a male to female.

 

[superheat6k]

I think that's a bit extreme, the OP was simply confused. He was asking about having a cable to plug into the 13A socket on his inverter, with the other end plugged into the shore power inlet. He wrongly described it as a "male to male", when it obviously has to be a male to female.

My comment was not aimed at the OP, he was asking a genuine question. That he was asking it meant he needed a clear answer. One respondent in particular was matter of fact that using a double ended male was OK.

 

[Lon nan Gruagach]

Now I appreciate we live in a risk averse world, with routine work requirement for Risk Assessment and Method Statements for the most innocuous of tasks. In amongst these tasks are some practices and potential situations which are genuinely lethal for which proper and diligent safety measures are required. OK so recreational boating sits outside the sometimes onerous practices required for safety in the workplace, but I utterly fail to understand that anyone would promote proudly that using a double ended male plugged lead is somehow OK. This is not bravado, it is IMHO stupidity.

This is particularly the case when some one else unplugs this lead ignorant of what he or she is then holding.

If just one person reading this thread does not create for themselves or perhaps stops using a double ended male male lead then I make no apologies to those who think it is OK to do so, and whom my response may annoy.

As the OP needs to ask this question suggests he does not understand the full implications of doing this from a safety perspective.

+lots

 

[pvb]

My comment was not aimed at the OP, he was asking a genuine question. That he was asking it meant he needed a clear answer. One respondent in particular was matter of fact that using a double ended male was OK.

Perhaps you should have replied to the other respondent directly. What the OP proposed is quite safe, although he used the wrong terminology.

 

[William_H]

Dangers

As said you have the risk of a plug with exposed pins carrying 240VAC if inverter is powered. Or at the other end if shore power is connected. Any iadvertent plug removal could result in a tragedy.
The risk of having power from both shore power and inverter is real the results could vary from ruined inverter to a fire.
To explain. When you put 2, 12v batteries in parallel you connect positive tyo positive and negative to negative Simple. If you connect pos to negative and negative to positive you get a 24v battery with a heavy short circuit on it. Probably exploding batteries. certainly ruination in a short time.
Now with 240vAC you have supply changing from positive to negative 50 times per second firstly on the shore power and likewise on the invverter output. Most likely the inverter will not be precisely 50 hertz. Thus when you connect them in parallel you can get the 2 in syncronism or completely in oppositionn. This latter being 760 v shorted out. Or any point in between and constantly varying in phase difference.
Yes power companies do parallel generators. The moment of connection is electronically set up to only happens when they are in syncronism. Once paralleled the generators tend to force one another to stay in sync. If one wants to go faster it takes the load so slows to get back in step. Connection out of step on big generators has been known to cause a complete generator to depart its mountings smash down walls and kill people. All very interesting but ceertainly your inverter could never fight with mains without losing.
So as said if you really want to connect to an installed 240vAC system. (And i would advocate against this as you don't want people who do not understand just plugging in any appliance thus loading your inverter and flattening your batteries) then you must have a system which will not allow shore power and inverter connected at one time and have no possibility of bare pins being powered. Be safe olewill

 

[pvb]

The risk of having power from both shore power and inverter is real the results could vary from ruined inverter to a fire

If you read the OP carefully, you'll see there's no such risk. He's proposing connecting the inverter to the shore power inlet socket. In order to do that the shore power lead would first have to be removed. So no risk.

 

[cliff]

I have two circuits on board. One feeds the outlets on the nave table and the "entertainment center" along with a =couple in the galley. This circuit is fed from the inverter. A second circuit feeds another couple of outlets in the galley and main cabin area. These are fed from the mains (shorepower) inlet and are only live when the inlet is powered up either by cable to shore power or by onboard generator. When inlet powered up the inverter connects the nav table outlets etc to the "mains" and switches over to charger mode to recharge the batteries - no faffing about with switches and no chance of the inverter outlet and "mains" getting "crossed".

 

[sailaboutvic]

I have a Sterling 1200watt (peak) inverter with a single 230v outlet. Obviously, its not designed to power the boats main circuit, but wondered if there's a reasonably safe way to hook it into the boats 230v circuit? Is it totally out of the question to simply run a male to male cable from inverter to shore power inlet?

I have an outside shore power socket and mains protected distribution box.

Dougal
We have a 3000w inverter and we have wire ours in a very simple way , the lead from the inverter has a female end which plug Into the male shore power plug , in that way the inverter goes through the RCD which lead to the main circuit on the boat ,in this way there is never a chance of the inverter and the shore power every being conected at he same time .
never put a male plug on the end of a live cable , I will tell you now if you do one day someone will pick that end up and at the less shock them self worst it will kill them .