In message ,
Richard Walker writes
Sparks wrote:
Richard Walker wrote:
Ed Sirett wrote:
On Mon, 08 Jan 2007 16:50:02 +0000, Richard Walker wrote:

Hi

Few years ago I bought a 2kW petrol generator to keep the home
running when the mains power failed. Used several times, no probs
except that the CH boiler locked out when the generator was
switched in. A reset and all worked fine.

Last week had another power cut but this time the CH boiler locked
out after about 30 secs even after re-setting (several times).
Everything else in the house works OK, including gas fired Rayburn
cooker, which is just the same sort of technology as the boiler.

snip
Generators are generally center tapped, so you end up with +115v on
one phase and -115 on the other.
This may cause a problem with your boiler.
With the generator running and the grid supply off, what are the
voltage measurements between...
L&N -
L&E -
N&E -
Sparks...
Hmmm... Voltage between L&E and N&E is just 85v when no load,
disconnected from the house wiring. Voltage between L&N is 240v.
Thought I had a reasonable understanding of electricity, but this has
me puzzled. Should I not connect the generator earth to the house earth?

The earth needs to be fairly close to neutral for flame sensing to work

sounds like the flame sense signal is getting lost

--
geoff