Cooker Hood Problem

[westward10]

Delete.

 

[PEG]

Hi,has the motor got speed control,and is this achieved via the controller itself?

 

[Derek Morrison]

Hi Derek and Welcome to the Forum !
Can I ask what size was the fuse that blew? Was it replaced and blew again? Sorry, just starter dumb questions. Do the lights still work? Probably it's in a million pieces just now I guess.
Edit - just reread OP so modified q.

Hi - The fuse which blew was a 3A. I said earlier it was a Fused spur but it was a plug and socket so the 3A fuse was in plug. I replaced and this never blew again. The lights work via the controller. The controller also provides speed control. 3 output speeds. The windings of the motor seem intact as I have measured between what I think to be the windings. The readings pretty much double then treble.Capacitor is healthy(tested). Tried testing separately motor and controller. When switching each output speed, a voltage 240Vac could be seen at each output wire of controller (red, black, blue to neutral). When connecting brown of motor to mains L, which is where I believe it has to be wired to, the other windings (wires from motor, Red, Black, Blue) all seem to have a voltage on them when separate from controller. Would this be backfeeding to the outputs of the controller? If so then the brown wire which I believed to be permanently live may not be the case. I just wired it as it had been before so assumed this to be correct.

 

[Wilko]

Ok, got it
With the fuse now not blowing, it may be the short(ish) circuit has removed itself, possibly by a track somewhere melting and leaving on open circuit? All of that stuff is likely in the controller and speed switch and that's now new, I think. That leaves the motor as a suspect perhaps?
Edit : another dumb one, sorry, have you confirmed the fuse in the spur still intact?

 

[Derek Morrison]

Hi Wilko
The controller and motor are both new now. The fuse is in a plug which plugs into a socket in the roof space directly above cooker hood, which has not blown. At present its in bits where I can bench test. Just doesnt work. The only thing which works via the controller is the lights. When I push button for lights, that works. When I push button for speed 1 - controller light latches on, speed 2 - same, speed 3 same.....just motor no turning. Wiring is easy, colour to colour apart from purple which goes to controller is the main live. Capcitor is ok. There doesn't seem to be a micro. The windings of the motor still seem intact. Just doesn't want to turn. Doesn't even make a sound.

 

[SparkyChick]

Hi Derek,

Any chance of some pictures?

 

[Derek Morrison]

Hi,has the motor got speed control,and is this achieved via the controller itself?

Yes, controller provides the speed control to the motor across the 3 windings, 3 different resistances measured. I think it was something like, 58 ohms, 118, and 165 ohms. This indicates all windings have same resistance but are supplied at different intervals via the controller I think.

 

[Derek Morrison]

Hi Derek,

Any chance of some pictures?

I took a couple photos on phone but new phone so I'll try and figure out how to upload. Cheers

 

[westward10]

Does the motor do anything, like a humm or just nowt.

 

[Derek Morrison]

Does the motor do anything, like a humm or just nowt.

Hi Westward
It does nowt mate.

 

[westward10]

Do you know type of motor, universal, shaded pole, split phase? I know you mentioned capacitor but is that definately to do with the motor.

 

[PEG]

Hi,it sounds like a Tapped winding type motor,which would have your four wires,usually the high speed is direct to main windings,(your first reading),with the medium and low being additional windings in series (your two other readings).

Has the motor got any nomenclature indicating it's operating voltage? only asking as some run at lower voltages,and if so,your mains injection may have upset it

Always tricky to diagnose from a keyboard...at this stage,i would still be keen to identify,type and fault...but i would have already fitted a new hood...just cheaper re: time spent

 

[Derek Morrison]

Hi,it sounds like a Tapped winding type motor,which would have your four wires,usually the high speed is direct to main windings,(your first reading),with the medium and low being additional windings in series (your two other readings).

Has the motor got any nomenclature indicating it's operating voltage? only asking as some run at lower voltages,and if so,your mains injection may have upset it

Always tricky to diagnose from a keyboard...at this stage,i would still be keen to identify,type and fault...but i would have already fitted a new hood...just cheaper re: time spent

Hi
The motor is a direct replacement for the old one so am unsure why it wouldn't work.I agree, I would have advised a new cooker hood had customer not already bought controller which sent us down this path.

 

[B4lamb]

Hj

Hi - The fuse which blew was a 3A. I said earlier it was a Fused spur but it was a plug and socket so the 3A fuse was in plug. I replaced and this never blew again. The lights work via the controller. The controller also provides speed control. 3 output speeds. The windings of the motor seem intact as I have measured between what I think to be the windings. The readings pretty much double then treble.Capacitor is healthy(tested). Tried testing separately motor and controller. When switching each output speed, a voltage 240Vac could be seen at each output wire of controller (red, black, blue to neutral). When connecting brown of motor to mains L, which is where I believe it has to be wired to, the other windings (wires from motor, Red, Black, Blue) all seem to have a voltage on them when separate from controller. Would this be backfeeding to the outputs of the controller? If so then the brown wire which I believed to be permanently live may not be the case. I just wired it as it had been before so assumed this to be correct.

I was presented with similar problems by my nephew who had the same cooker hood and the fan stopped working. Motor winding resistance of increasing value was measurable between all colours other than to brown in inverse proportion to motor speed selection. The important thing was there was no resistance reading between brown and any other colour, ie open circuit. Brown is permanently connected to live and the controller applies neutral to one if the other coloured wires depending on the motor speed switch pressed. I concluded the motor had blown as resistance should have been measurable between brown and any of the other colours. As you found when the motor is connected full 240V is measured between brown and all other colours. This is because all of the other colours are interconnected via motor windings, they are just like taps of a transformer winding. My conclusion of a blown motor was correct as a new motor £53 solved the problem. Why your motor didn't work is a mystery but i'd guess you were supplied with a duff motor.