pedroinlondon Posted February 27, 2020 Report Share Posted February 27, 2020 Hi all I've bought a 2.5K W metal frame petrol generator (Briggs & Stratton Sprint 3200A) and was strongly advised to earthing it before using it again. There are no instructions on the manual regarding this (or much of anyting else) and so I took to google for answers. I understand after a short general search that one way of doing this would be connecting a copper cable to the earthing nut of the generator and the other end of the cable to a copper rod (Screwfix product 87633?) hammered a foot or so into the ground, preferably wet ground. I understand there are several variables that may affect the reliability of the "system" (the quality of the connection of the cable to the rod;the state and type of the ground; the lenght of the cable; etc; etc) but does anyone have a tried and preferably tested way of doing this? The genie is over 60kgs so I'd like to leave it on the roof of the boat, so the cable lenght will be around 3 meters. I have some 7mm multi strand copper cable left over, can I use it? Ideas and suggestions welcome Thanks Link to comment Share on other sites More sharing options...
Tony Brooks Posted February 27, 2020 Report Share Posted February 27, 2020 If its on the boat i suspect but do not know that it needs earthing to the boat hull, not the soil or water. Someone who really knows will be along soon. Link to comment Share on other sites More sharing options...
OldGoat Posted February 27, 2020 Report Share Posted February 27, 2020 60 kilos on the roof and you'll tip over as well as deafening the neighbours - nothing around to deaden the sound... Link to comment Share on other sites More sharing options...
WotEver Posted February 27, 2020 Report Share Posted February 27, 2020 Check with a multimeter (set to continuity) if the earth pin on the generator outlet is connected to the generator frame/engine. If it is, then I see no need to run an earth spike. Link to comment Share on other sites More sharing options...
LadyG Posted February 27, 2020 Report Share Posted February 27, 2020 (edited) I can just hear it from here! [Goole] ? Edited February 27, 2020 by LadyG Link to comment Share on other sites More sharing options...
Chewbacka Posted February 27, 2020 Report Share Posted February 27, 2020 5 hours ago, OldGoat said: 60 kilos on the roof and you'll tip over as well as deafening the neighbours - nothing around to deaden the sound... I weigh about 85kg and the boat doesn’t tip over when I stand on the roof, however generators on the roof can be close to vents & windows which might under certain weather conditions put CO into the boat. Link to comment Share on other sites More sharing options...
Richard10002 Posted February 28, 2020 Report Share Posted February 28, 2020 6 hours ago, OldGoat said: 60 kilos on the roof and you'll tip over as well as deafening the neighbours - nothing around to deaden the sound... I used to put 6 x 20 kilo bags of coal on the roof to keep the boat level. It probably changed the list to port from about 5 degrees, to zero. Not sure at what angle stability would disappear, but I think it would take more than double the 120 kilos, and maybe a lot more, to reach it Link to comment Share on other sites More sharing options...
pedroinlondon Posted February 28, 2020 Author Report Share Posted February 28, 2020 (edited) 13 hours ago, WotEver said: Check with a multimeter (set to continuity) if the earth pin on the generator outlet is connected to the generator frame/engine. If it is, then I see no need to run an earth spike. Hi Wot It's not. There's a nut+bolt connection for a cable on it. Edited February 28, 2020 by pedroinlondon Link to comment Share on other sites More sharing options...
Alan de Enfield Posted February 28, 2020 Report Share Posted February 28, 2020 (edited) I'd be more than a little concerned that the manufacturer doesn't appear to quote the 'noise levels'. This looks like a typical Building site "frame generator", and, if it is then the noise reverberating around inside the boat is likely to make it impossible to be inside when the generator is running. You are not going to be popular with any neighbours either. https://www.briggsandstratton.com/eu/en_gb/product-catalog/generators/portable-petrol-generators/sprint-3200a-portable-petrol-generator.html The picture shows an earth strap running from the generator to the frame. Edited February 28, 2020 by Alan de Enfield Link to comment Share on other sites More sharing options...
David Mack Posted February 28, 2020 Report Share Posted February 28, 2020 13 minutes ago, Alan de Enfield said: The picture shows an earth strap running from the generator to the frame But that might just be connecting the main frame to the alternator casing, and not necessarily to the wiring. 1 Link to comment Share on other sites More sharing options...
WotEver Posted February 28, 2020 Report Share Posted February 28, 2020 44 minutes ago, Alan de Enfield said: I'd be more than a little concerned that the manufacturer doesn't appear to quote the 'noise levels'. JustGenerators lists it as 74dB! (But no distance is stated, nor the weighting). Link to comment Share on other sites More sharing options...
Alan de Enfield Posted February 28, 2020 Report Share Posted February 28, 2020 (edited) Let’s look at noise levels first. Many areas have noise regulations that may impact generator usage, particularly at night. This is especially the case for residential areas – so if you’re planning on using the generator around the home or work shed, you must consider the noise level. For obvious reasons, loud generators are also not recommended for camping, caravanning and outdoor events unless you want to make enemies! The good news is most generators are labeled with a decibel rating. This is measured at an industry standard of seven metres away from the source (in this case, the generator). Here’s how it works: for every increase in 10 decibels, the generator noise level is roughly doubled. So a generator that runs at 70 decibels is ten times as loud as a generator that runs at 60 decibels. https://www.mygenerator.com.au/blog/4-asked-question-heavy-noisy-generator/ Edited February 28, 2020 by Alan de Enfield Link to comment Share on other sites More sharing options...
WotEver Posted February 28, 2020 Report Share Posted February 28, 2020 1 hour ago, Alan de Enfield said: Here’s how it works: for every increase in 10 decibels, the generator noise level is roughly doubled. So a generator that runs at 70 decibels is ten times as loud as a generator that runs at 60 decibels. No, it is twice as loud. Because it is 10dB louder, which is a doubling of loudness (more or less). 3dB is a doubling of power. 6dB is a doubling of SPL. 10dB is a subjective doubling of perceived loudness. Link to comment Share on other sites More sharing options...
Alan de Enfield Posted February 28, 2020 Report Share Posted February 28, 2020 (edited) 4 minutes ago, WotEver said: No, it is twice as loud. Because it is 10dB louder, which is a doubling of loudness (more or less). 3dB is a doubling of power. 6dB is a doubling of SPL. 10dB is a subjective doubling of perceived loudness. Yes - That's what the table shows. So, the difference in 'loudness' between a Honda EU200I (52dB) and the Briggs and Stratton frame genny (74bD) is "it is 4x louder" to the ear. Edited February 28, 2020 by Alan de Enfield Link to comment Share on other sites More sharing options...
WotEver Posted February 28, 2020 Report Share Posted February 28, 2020 2 minutes ago, Alan de Enfield said: Yes - That's what the table shows. But you said it was ten times as loud. 1 Link to comment Share on other sites More sharing options...
Alan de Enfield Posted February 28, 2020 Report Share Posted February 28, 2020 1 minute ago, WotEver said: But you said it was ten times as loud. The article I quoted did say that, but the table below showed the loudness' was 2x but the 'sound intensity' was 10x Link to comment Share on other sites More sharing options...
WotEver Posted February 28, 2020 Report Share Posted February 28, 2020 Just now, Alan de Enfield said: The article I quoted did say that, but the table below showed the loudness' was 2x but the 'sound intensity' was 10x I’ve emailed them before about their text being incorrect. They didn’t reply and they didn’t correct it. 1 Link to comment Share on other sites More sharing options...
Alan de Enfield Posted February 28, 2020 Report Share Posted February 28, 2020 I still would not want to be moored within half-a-mile of a boat with a 74dB generator on its roof. Sound travels well over water. I'll forecast that however well chained down it is, it will 'end up in the water'. Link to comment Share on other sites More sharing options...
cuthound Posted February 28, 2020 Report Share Posted February 28, 2020 When specifying standby generators in cities such as London, I used to require 70dBA 1 metre from any inlet or outlet, including exhaust and 50dBA at 1 metre at the site perimeter. Anything noisier than th2st will upset close neighbours if the generators run for any length of time. Link to comment Share on other sites More sharing options...
David Mack Posted February 28, 2020 Report Share Posted February 28, 2020 41 minutes ago, cuthound said: When specifying standby generators in cities such as London, I used to require 70dBA 1 metre from any inlet or outlet, including exhaust and 50dBA at 1 metre at the site perimeter. And I assume you can't buy anything that quiet which is portable and at a price the average boater is prepared to pay. Link to comment Share on other sites More sharing options...
Alan de Enfield Posted February 28, 2020 Report Share Posted February 28, 2020 21 minutes ago, David Mack said: And I assume you can't buy anything that quiet which is portable and at a price the average boater is prepared to pay. Certainly not for the £250 the Briggs & Stratton costs. The 'average boater' will be paying £1000+ for the Honda EU22I equivalent. Link to comment Share on other sites More sharing options...
Detling Posted February 28, 2020 Report Share Posted February 28, 2020 There was a boater in london had one like that, when we walked around St Pancras a few yeas ago, to make matters worse he moored partially under a bridge, with the genny under the bridge. He started it and went to the nearby bridge pub. Apparently after a few days of this the locals from the pub took matters into their own hands and threw both him and his genny into the cut and drove his boat away and put it on the next lock landing, there being nowhere else to moor. We could hear it at least half a mile away and we were in a big city, so noisy. Link to comment Share on other sites More sharing options...
cuthound Posted February 28, 2020 Report Share Posted February 28, 2020 (edited) 46 minutes ago, David Mack said: And I assume you can't buy anything that quiet which is portable and at a price the average boater is prepared to pay. Very true, 7 years ago, when I last worked a standby generator plus its associated noise attenuation, fuel tankage etc was around £1,000 per kVA, for a typical 500-3000kVA installation. Edited February 28, 2020 by cuthound Clarification Link to comment Share on other sites More sharing options...
russ2903 Posted February 28, 2020 Report Share Posted February 28, 2020 You mention that you intend your genny to stay on the roof. Noise and vibrations apart, you will need to move it if you intend to cruise away from London some bridges are too low to allow your boat plus genny to pass under. Link to comment Share on other sites More sharing options...
magnetman Posted February 28, 2020 Report Share Posted February 28, 2020 A copper rod wired to the genny and planted amongst the Radishes should work for earthing. Link to comment Share on other sites More sharing options...
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