goodo123 Posted January 22, 2013 Report Share Posted January 22, 2013 Resistance check accross Spst relay output what operates the solenoid, if there is a big resistance across this then it will effect coil voltage and make it burn out. As for the operated by earth comment I think you are getting your wires twisted. Earth isn't normally used as a current conducter, it is their for safety reasons. Granted certain things do use it I.e. inverters dischargeing capacitors or some small pcb's but quite rare. Auto electrician: although earth is used in car wiring as a effective -ve it isn't normally done for other things. Even though earth and neutral are typically connected at the point of power generation (but not all the time). To check resistance across relay output it may have to be done live (if it uses solid state relays) so if you don't understand how conductivity is measured or working live I'd get a leccy to have a look. No matter how hard I try I can't see where/how someone came up with earth supplies the coil. As for the comment about what resistance should a good earth have well it depends on what context and where, how and why your measuring it. For earth continuity the lower resistance the better, for insulation resistance the higher the better, I know 0.5 ohms gets banded about but it depends on many factors and 0.5 ohms for what? Zt? Zs? ...... Overall if in doubt get a sparks in mate, to many open/dangerous answers given here. It is gas and if it operates incorrectly after trying these suggestions where would the blame lie? Well this guy on a forum said do x y z lol. Experience: electrical technician. Quote Link to comment Share on other sites More sharing options...
bigadam Posted January 22, 2013 Report Share Posted January 22, 2013 Hit it with hammer u may have a eddie in the resestivity of tge coil if the enviromental conditions are such that it has an electro magnetic flux density issue. Failing that hit it with a bigger hammer Quote Link to comment Share on other sites More sharing options...
aga man Posted January 22, 2013 Author Report Share Posted January 22, 2013 thanks for your postgoodo123 in your opion looking at the diagram coul the fan have an afect on the voltage supplied to the solenoid? Quote Link to comment Share on other sites More sharing options...
proud dad Posted January 22, 2013 Report Share Posted January 22, 2013 Hit it with hammer u may have a eddie in the resestivity of tge coil if the enviromental conditions are such that it has an electro magnetic flux density issue. Failing that hit it with a bigger hammer And if that fails, hit it again. Quote Link to comment Share on other sites More sharing options...
goodo123 Posted January 22, 2013 Report Share Posted January 22, 2013 It could do but its unlikely, they share a common supply so there is a possibility that when the fan starts it will pull more load but shouldnt be enough to effect the solonoid. If it's easy enough to do remove cover on stat and give it a whiff, sometimes you can smell if things aren't right (sometimes it f......... Stinks) As a footnote, check all electrical connections are tight and secure LOL Quote Link to comment Share on other sites More sharing options...
aga man Posted January 22, 2013 Author Report Share Posted January 22, 2013 thanks goodo123 i have suspected the flue thermostat. i fitted the fan on january the 4th as the old dried up{common on these}. it has been fine for three weeks and the yesterday started this. i have checked all connections. Quote Link to comment Share on other sites More sharing options...
goodo123 Posted January 22, 2013 Report Share Posted January 22, 2013 I'm not saying it is this without looking but worth a shot. Quote Link to comment Share on other sites More sharing options...
aga man Posted January 22, 2013 Author Report Share Posted January 22, 2013 I'm not saying it is this without looking but worth a shot. i know mate, i wouldn't expect you to tell me the fault. i guess i wanted to be fairly sure about the fan affecting supply to the solenoid. seems obvious you can read a wiring diagram. Quote Link to comment Share on other sites More sharing options...
HDAV Posted January 22, 2013 Report Share Posted January 22, 2013 I think are is a bit of AC/DC confusion in this thread........ AC circuits need live and neutral, earth is protective only.... DC is +ve and -ve (often GND) but not always..... Gas as in flammable killer stuff you can't see? I'll leave it to the experts. Triple check the wiring to solenoid and try a capacitor across it........ Quote Link to comment Share on other sites More sharing options...
goodo123 Posted January 22, 2013 Report Share Posted January 22, 2013 Well it's my trade. Good luck Why bother with a capacitor? It didn't need one before? Quote Link to comment Share on other sites More sharing options...
aga man Posted January 22, 2013 Author Report Share Posted January 22, 2013 I think are is a bit of AC/DC confusion in this thread........ AC circuits need live and neutral, earth is protective only.... DC is +ve and -ve (often GND) but not always..... Gas as in flammable killer stuff you can't see? I'll leave it to the experts. Triple check the wiring to solenoid and try a capacitor across it........ don't worry fella. i am a gas safe registered engineer. as for the electrics i had a local sparky out who knew less than me and the manufacturers technical were useless too. i will sort the problem just wanted advice from any sparky's on the diagram. atb aga man Quote Link to comment Share on other sites More sharing options...
goodo123 Posted January 23, 2013 Report Share Posted January 23, 2013 Was the local sparks a house basher? I wouldn't expect him to know but saying that the cct is pretty simple for any lekky I would have thought..... Quote Link to comment Share on other sites More sharing options...
djgeoff Posted January 23, 2013 Report Share Posted January 23, 2013 ok i am a sparky but no expert on boilers, but looking at the diagram nothing works down to earth, it is showing that the case of the fan, solenoid and incoming earth are bolted to the case, as earths should be, if there was any voltage / current to earth and you have rcd devices at the mains consumer unit, it would be tripping every 5 mins. ( fig of speech) looking at the diagram again it states during normal operation at slow speed, so i am going to assume as thermostat 1 ( one on left) is making contact ( in circuit p - 1) then goes to solenoid then return form solenoid to neutral. as someone has already asked what does this solenoid actually control? i suspect the second stat ( on right) is the jobby that controls the two speeds of the fan position 1 is slow and position 2 fast, and p is the permanent live looped from p of the first stat. this is a pure guess here but you stated after a short while the solenoid burnt out, if the solenoid is moving ok. then i think it may lie with the fan when second stat kicks in it switches over to fast speed . like i said pure guess, i am no gas engineer. but i can tell you that should have very little to no current or voltage to the earth / protective conductors ( for the benefit of other sparkys yeh i know you may get some small amounts of voltage on earths sometimes) hope this is of help Quote Link to comment Share on other sites More sharing options...
Scottoj18 Posted January 23, 2013 Report Share Posted January 23, 2013 Check the hz rating on the solenoid should b 50hz 240v ..when the old fan popped it might of damaged something in the 80* stat. reduced current to the solenoid using a resistor this could prevent over heating if over current is the issue.. I'm just chucking idears out.... there's nothing wrong with the diagram ... Also any voltage between n2 and earth when the fan is running? Quote Link to comment Share on other sites More sharing options...
Elby Posted January 23, 2013 Report Share Posted January 23, 2013 some plonkers on here,if you have no idea how to follow this diagram don`t give the chap duff advice what does the solenoid do??? check it is n`t stuck and needs freed up. if energised and not able to move freely it will born out again I know nothing about electrics but I can clearly see what's wrong ^^^^^ here.It's total misuse of the space bar and having no idea where one of these ' goes Quote Link to comment Share on other sites More sharing options...
bullet1747 Posted January 23, 2013 Report Share Posted January 23, 2013 Check the solnoid in k ohms. It sounds if it could be that , let us know wot the reading is Quote Link to comment Share on other sites More sharing options...
djgeoff Posted January 23, 2013 Report Share Posted January 23, 2013 r well we cant all be perfect can we... Quote Link to comment Share on other sites More sharing options...
bullet1747 Posted January 23, 2013 Report Share Posted January 23, 2013 r well we cant all be perfect can we... Y wot made you say that Quote Link to comment Share on other sites More sharing options...
HDAV Posted January 23, 2013 Report Share Posted January 23, 2013 Why bother with a capacitor? It didn't need one before? Capacitor will smooth the power, reduce EMI and other nasties, Old fan died and new solenoid burnt out so something is wrong... burn outs are normally over current faults so what would cause this to draw more current? Is replacement fan same motor rating as old one? Did the manufacturer "upgrade" the fan after original design? Is a different solenoid used on new units with new fan? I have seen a similar issue where a relay kept burning out and it was due tot he load coming off the coil feed rather than the switched NO out of the relay (contacter) checking voltages didn't help........ Does solenoid have multiple connections? or just 2? Make sure Fan isnt powered from an out on the solenoid. Quote Link to comment Share on other sites More sharing options...
Diceman Posted January 23, 2013 Report Share Posted January 23, 2013 If anyone else is enjoying reading posts from sparkies arguing with each other, may I suggest the Electricians forums on the screwfix website? Absolutely hilarious. Every one of them seems to think all the others are complete idiots. What is it about you lot that makes you so grumpy? Quote Link to comment Share on other sites More sharing options...
bullet1747 Posted January 23, 2013 Report Share Posted January 23, 2013 I'm not grumpy or arguing Quote Link to comment Share on other sites More sharing options...
HDAV Posted January 23, 2013 Report Share Posted January 23, 2013 What is it about you lot that makes you so grumpy? The Zs test.....attach neutral to left testicle and live to right if you last longer than 3 seconds the job is complete........ Quote Link to comment Share on other sites More sharing options...
bigadam Posted January 23, 2013 Report Share Posted January 23, 2013 I am a highly qualified sparkie and I still say hit it with a hammer or get a new boiler Quote Link to comment Share on other sites More sharing options...
goodo123 Posted January 24, 2013 Report Share Posted January 24, 2013 Capacitor will smith power but if sized incorrectly will create resonance and I'm assuming u mean emf well the control cct is analog so not much chance of frying cct boards if the fan did draw more current how would this effect the solonoid? It effectively has its own supply and the solonoid will have 3 connections or a plug earth live and neutral, maybe not earth if double insulated. Love the Zs? Test post, won't be trying that myself tho where do you put the earth probe? Quote Link to comment Share on other sites More sharing options...
evo Posted January 24, 2013 Report Share Posted January 24, 2013 try resetting the randsolli button next to the googloid switch,,if that doesn,t work then i,m fumixed Quote Link to comment Share on other sites More sharing options...
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