Invertors

[JohnHall]

I have just bought a 300 Watt invertor to use to charge my mobile phone and laptop batteries whilst on my boat.

 

The invertor connects to a normal car battery but I am not sure from the instructions whether I need to connect to an Earth?

 

Does anyone have any ideas about this,

 

many thanks

 

John

[Guest]

This could prove interesting! Our (Sterling) inverter states it should be earthed to the hull (I refer to the 240v side). I have earthed it to the hull as advised, and fitted an RCD unit on the 240 V circuit. The man who examined the boat for BSC said the RCD wouldn't work with an inverter anyway (??-his words not mine). I am unsure as to wether inverters (or any 240 v ac supply) can cause any galvanic problems when earthed in this manner, but will watch the hull carefully. Any offers or advice from others?

[John Orentas]

John.

 

All you can do is be guided by the unit itself. If there is no facility for earthing then don't bother, especially as the appliance you are powering will most likely not to have an earth either.

 

The concept of "Earthing" comes from the days when appliances had metallic chassis' and enclosures. Strangely people think "earths are good" when in fact most electrocutions (and they are rare) are the result of a persons body making a path to earth.

 

The best precaution against electric shock is the use of heavy and multiple insulation, and of course the competent wiring of all appliances. Of equal importance, make good permanent connections on the 12 volt side with the correct size of wiring. (No crocodile clips)

[David Schweizer]

This could prove interesting! Our (Sterling) inverter states it should be earthed to the hull (I refer to the 240v side).  I have earthed it to the hull  as advised,

<{POST_SNAPBACK}>

This could prove even more interesting. I have the instuctions for my (Sterling) inverter in front of me, and there is no mention of earthing it, nor is there any provision on the unit for an earth. I agree with John on this one, as none of the appliances I intend to operate from the inverter uses an earth, connecting one will be irrelevant.

[NB Willawaw]

Please check out existing thread

 

http://www.canalworld.net/forums/index.php...9515entry9515

[Guest]

David,

My particular inverter is a Sterling UPS type requiring no changeover switch. Therefore the shoreline earth and the earth from the inverter all join on a common terminal, and as the shoreline must be earthed, so the inverter is by default. I probably haven't explained this very well, but that is how it works. That may explain why your inverter is different.

[DHutch]

Strangely people think "earths are good" when in fact most electrocutions (and they are rare) are the result of a persons body making a path to earth.

 

Yeah, at one time they where very big into the "earth free zone" thing

 

- The idea was that i wouldnt matter is your light switch/applience became live, becuase there was no earth to touch.

 

 

Daniel

[Derek]

I have just bought a 300 Watt invertor to use to charge my mobile phone and laptop batteries whilst on my boat.

 

The invertor connects to a normal car battery but I am not sure from the instructions whether I need to connect to an Earth?

 

Does anyone have any ideas about this,

 

many thanks

 

John

<{POST_SNAPBACK}>

I charge my mobile with a car charger straight off my 12v system. All you need is a 12v plug to a cigarette lighter adaptor, about 3 quid from any decent caravanne shop (or ten quid from a chandlers! )

 

Derek

Edited April 21, 2005 by Derek

[DHutch]

I charge my mobile with a car charger straight off my 12v system.

 

Yeah, we charge ours off our 24v system, via 12v voltage converter, and a mokia car charger.

- Im junna have to get a 5v regulator for my MP3 player tho, as i cant live without my tunes!! (last year of lived with using a load of CDs, but this year i've got sort that)

 

 

 

Daniel

[spectric]

Hi all

 

The term " Earth " originates because the star point of the 3 phase national grid system is connected to the ground, ie earth. This is your neutral or return for all distribution systems. The whole point of the earth connection is that providing there is a circuit protection device in the live, ie fuse or mcb and if all metal work is grounded then if there is a short circuit the fuse will blow and prevent any metalwork becoming live.

 

This also means that if you touch a live conductor then you could be electrocuted if there is an electrical path through you to ground.

 

In the case of an invertor which is supplied from a Dc source, the neutral is not grounded or earth referenced & the 12 volt negative input is not connected to the 240 volt output Neutral.

 

Hope this makes sense.

 

all the best Roy

[David Schweizer]

I charge my mobile with a car charger straight off my 12v system. All you need is a 12v plug to a cigarette lighter adaptor, about 3 quid from any decent caravanne shop (or ten quid from a chandlers! )

 

Derek

<{POST_SNAPBACK}>

So do I, also usefull to charge in the car. I managed to persuade the phone supply shop to give me one as part of the deal. If you have a phone that is no longer in production, there are lots of companies on the internet supplying them, also look on eBay.