jeb Posted November 20, 2008 Report Share Posted November 20, 2008 Whilst tinkering with my alde boiler today I managed to accidentaly dislodge the negative cable, I was a bit puzzled at first if indeed it was the negative connection to the Alde because the boiler was still running. It soon became apparent that it was indeed the negative to the Alde so I turned the power off,out of curiosity I turned the power back on and the boiler fired up without the negative connected. Is this normal ? Link to comment Share on other sites More sharing options...
Gibbo Posted November 20, 2008 Report Share Posted November 20, 2008 Whilst tinkering with my alde boiler today I managed to accidentaly dislodge the negative cable, I was a bit puzzled at first if indeed it was the negative connection to the Alde because the boiler was still running. It soon became apparent that it was indeed the negative to the Alde so I turned the power off,out of curiosity I turned the power back on and the boiler fired up without the negative connected. Is this normal ? Yes. It's probably picking up a negative from the hull via another route. Like a gas pipe (!!!!) or water pipe. Or possibly the casing touching the hull. I don't like conductive gas and water pipes for this very reason. I like to put a small insulated section in them. Gibbo Link to comment Share on other sites More sharing options...
Keeping Up Posted November 20, 2008 Report Share Posted November 20, 2008 I don't like conductive gas and water pipes for this very reason. I like to put a small insulated section in them. Is that permitted for gas pipes? Link to comment Share on other sites More sharing options...
Gibbo Posted November 20, 2008 Report Share Posted November 20, 2008 Is that permitted for gas pipes? I've no idea I haven't done installations for a long time. But I don't see why not. The pipes to the gas bottles are rubber. There are rubber gas pipes inside many gas burners. Things may have changed. I dunno. Gibbo Link to comment Share on other sites More sharing options...
jeb Posted November 20, 2008 Author Report Share Posted November 20, 2008 Yes. It's probably picking up a negative from the hull via another route. Like a gas pipe (!!!!) or water pipe. Or possibly the casing touching the hull. I don't like conductive gas and water pipes for this very reason. I like to put a small insulated section in them. Gibbo Thanks Gibbo I was thinking gas pipe and is now certain, but how to insulate the pipe where it exits the gas locker and passes through the front bulkhead. Hmm Link to comment Share on other sites More sharing options...
dor Posted November 20, 2008 Report Share Posted November 20, 2008 (edited) I shouldn't worry about the gas pipe. The current is only very small. it is probably earthing through the flue as well. But reconnect the direct negative. Edited November 20, 2008 by dor Link to comment Share on other sites More sharing options...
jeb Posted November 20, 2008 Author Report Share Posted November 20, 2008 I shouldn't worry about the gas pipe. The current is only very small. it is probably earthing through the flue as well. But reconnect the direct negative. Would there be enough current to power my tunnel light and horn ? NO NO NO only joking Thanks Dor Link to comment Share on other sites More sharing options...
simonk Posted November 21, 2008 Report Share Posted November 21, 2008 Whilst tinkering with my alde boiler today I managed to accidentaly dislodge the negative cable, I was a bit puzzled at first if indeed it was the negative connection to the Alde because the boiler was still running. It soon became apparent that it was indeed the negative to the Alde so I turned the power off,out of curiosity I turned the power back on and the boiler fired up without the negative connected. Is this normal ? I found this with my Alde installation too. Strange readings were happening as the DC system was not earthed to the hull (no discussion required on that...). It is now but I thought it a good idea to stop these spurious hull connections in any case - since my boat is 24V and the Alde needs 12V I used an isolated DC-DC converter so that sorted it out. If you look inside the Alde there is a connection from the -ve input to the metal work - I tried removing this but the ignition spark seemed to click constantly. (The other place I found a spurious hull earth was between a negative pin and the shell in one of those 3-pin 'oudoor' plugs for the front light and horn, via a retaining screw). Link to comment Share on other sites More sharing options...
chris w Posted November 21, 2008 Report Share Posted November 21, 2008 (The other place I found a spurious hull earth was between a negative pin and the shell in one of those 3-pin 'oudoor' plugs for the front light and horn, via a retaining screw). Another favourite hull connection is if you have a radio aerial fitted through the roof and you didn't cut the braid in the aerial lead and fit an RF bypass capacitor across the cut. Chris Link to comment Share on other sites More sharing options...
Featured Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now