Bonding / Earth

[WotEver]

Just now, cuthound said:

Agreed, but they are separated for is practical reasons, (ease of identifying each earth point) rather than electrical reasons As the hull effectively commons the two earth points.

And safety. Let's say the bonding stud fell off the hull. You'd never know until you had a live to earth short and now every piece of 12V equipment is live. Can't happen with separate studs. 

Okay, an unlikely scenario, but possible. 

[cuthound]

1 minute ago, WotEver said:

And safety. Let's say the bonding stud fell off the hull. You'd never know until you had a live to earth short and now every piece of 12V equipment is live. Can't happen with separate studs. 

Okay, an unlikely scenario, but possible. 

Unless the a.c. stud fell off and the dc stud fell off and they touched each other. An even unliklier scenario 

[WotEver]

1 minute ago, cuthound said:

Unless the a.c. stud fell off and the dc stud fell off and they touched each other. An even unliklier scenario 

Shall we now discuss what size RCD should be used on a centre tapped supply? 

[Col_T]

Apologies for high-jacking your thread, again!, Mohsen.

I guess that an earth hull bond is usually a threaded stud welded to the hull. Would a bolt screwed through an internal steel upright work okay?? Before anyone mentions it, no, I don't mean the side of the hull!!!

[WotEver]

51 minutes ago, Col_T said:

Apologies for high-jacking your thread, again!, Mohsen.

I guess that an earth hull bond is usually a threaded stud welded to the hull. Would a bolt screwed through an internal steel upright work okay?? Before anyone mentions it, no, I don't mean the side of the hull!!!

Yes. 

You could put it through the base plate if you really wanted to

Obviously clean any paint off the bearer first - you're aiming for a really good electrical connection (which is why welding works well). 

[cuthound]

1 hour ago, Col_T said:

Apologies for high-jacking your thread, again!, Mohsen.

I guess that an earth hull bond is usually a threaded stud welded to the hull. Would a bolt screwed through an internal steel upright work okay?? Before anyone mentions it, no, I don't mean the side of the hull!!!

Yes, the  metal work of industrial power switchboards are earthed this way, and are designed to handle instananeous faults much larger than anything likely to be experienced on a boat.

[Col_T]

Excellent!

Thanks, gentlemen.

[Tom llewellyn]

W

Quote

Hi All, On my narrowboat when I test my plug sockets it says 'earth is missing' is this a problem?There is an earth wire going into all the plug sockets but can't see where its earthing on the boat. I'm running the power form my cotek 2000W pure sine wave inverter. Often when even modest appliances are plugged into the sockets like fans etc the inverter says there is an overload issue. Are you supposed to attach a earth wire from the ground connector on the inverter? What's the best way to do it?  I can't see where the earth wire is earthed on connected on my narrowboat. Warmly Tom  

 

Edited July 24, 2021 by Tom llewellyn

[blackrose]

Assuming what's quoted above by Tom is a new question rather than a quote from the old thread, then it sounds like you need a qualified marine electrician to have a look at it. You shouldn't be attempting this stuff yourself. Mains electrics can kill you or someone else.

[ditchcrawler]

1 hour ago, Tom llewellyn said:

W

 

I have just had a wiz through the downloads and they state the 3000 is neutral earth bonded but they make no mention for the 2000 series. They do state the chassis must be grounded.

[Tom llewellyn]

Hi Brain,

 

Thank you for your help! This is the best manual I can find for what I have the Cotek SK2000 (the slightly older model). https://www.manualslib.com/manual/756317/Cotek-Sk700-112.html?page=20#manual Says on page 20 

3-2-4. Use wire # 8 AWG to connect Chassis ground with vehicle chassis

Over Voltage

Model

Shut-

dWARNING!

WARNING: Operating the inverter without a proper ground

Connection may cause an electrical hazard