HELP

[Dave Davison]

Writing in the hope that among loungers /readers there will be an expert in all things electrical. The lawn mower shown below developed what I suspect is a fault with the switch but I'm led to believe a replacement is rather pricy so would like to incorporate another suitable switch on the handle BUT connecting the wires to a mains plug does not activate the motor. Can anyone enlighten me as it breaks my heart to have to fork out a lot of money to mend this one or trash it and buy a new one when -otherwise- it is very efficient. Regards Dave.

[Jezza]

It sounds silly, but have you checked the fuse? A switch is about £10 Switch

How about the thermal cut out

[Dave Davison]

Hi Jezza..............thanks for the feedback the price shown in the link is much less painful than what I was quoted so it's a a welcome alternative. As for testing the fuse, yep I followed the usual steps that one does with trying to ascertain the cause of such a malfunctuion and things pointed to the switch. Strange thing is though, I suspect there must be some other issue because when I couple the two leads that come from the motor directly to a supply nothing happens which of course could point to the motor. However, prior to the fault developing the motor ran fine with no trace of a smell that is ususally a hint that the motor is on it's way out. Will keep the link to the supplier in mind though as the price is very reasonable. Thanks for the feed back dave.

[viking33]

If you are connecting the two motor leads, directly to the power source, you eliminate everything but the motor. Assuming the motor is designed to operate on full mains power, then the motor is defective not any switch or fuse. A motor doesn't have to have a burnt smell to show that it's gong bad.

[hlewton]

I'm not entirely certain if this will help or not but I'd start by using a volt meter to determine if there were a short in the motor. I think a quick continuity check may give you the answer.

[Leif]

I'm not entirely certain if this will help or not but I'd start by using a volt meter to determine if there were a short in the motor. I think a quick continuity check may give you the answer.

I suspect that if there were a short (circuit), the fuse would blow. But a continuity check may help in determining if the motor circuit is open-circuit or not. However, this is not foolproof, as there may be capacitors in the circuit which would cause a misleading reading.

If a voltmeter is available, a check to see if mains voltage is available on the input and output to the switch when operated, and if so, a check that the same voltage is reaching the motor itself would be useful.

(I still haven't forgiven my wife who, after attempting to fulfil her wifely-garden-duties, swore our mains-operated hedge-trimmer had failed for absolutely no reason. After splashing out on a rechargeable-battery type, I then noticed the mains cable had been half-severed - presumably by the sharp, cutty bits at the business end of the trimmer...)

[GeoffW]

Be careful. Now she'll be claiming she severed the cord of the cordless one.

[jstevens]

Leif,

I would have replaced it with this one.

Spoiler

el_pic.jpg

Just be careful with the one you choose.

Regards,
John

[Leif]

Thanks for the idea John, but those blades look a bit dangerous.

If she messes up again, this is what I'll suggest:

Spoiler

x.jpg

[jstevens]

I wish I would have thought of that.

Brilliant!!!
John

[hlewton]

Leif,

I would have replaced it with this one.

Spoiler

el_pic.jpg

Just be careful with the one you choose.

Regards,
John

Can't wait till mine goes bad if that is an option.

[viking33]

I'm not entirely certain if this will help or not but I'd start by using a volt meter to determine if there were a short in the motor. I think a quick continuity check may give you the answer.

The one problem with that is a voltmeter does not check continuity, an Ohmmeter does. Even a continuity test may not reveal much more than, if the motor windings were intact or not. A very low resistance reading may even be misleading because the motor windings are just a coil of wire with low resistance anyway, but shorted turns might cause it to be inoperative. Continuity would not reveal that fact, usually.

[hlewton]

The one problem with that is a voltmeter does not check continuity, an Ohmmeter does.

Sorry I used the wrong term. I should have said go out and buy a "Fluke 77 multimeter" like I have. It will not only check volts both AC and DC it will also check for continuity both digitally or audibly. I guess that would have been more accurate. Sorry for the confusion but I am not an electrician or electronics engineer. I only know what usually works for me and checking continuity often can help identify the problem. At least it has always been a good starting point for me in the past.

[viking33]

The one problem with that is a voltmeter does not check continuity, an Ohmmeter does.

Sorry I used the wrong term. I should have said go out and buy a "Fluke 77 multimeter" like I have. It will not only check volts both AC and DC it will also check for continuity both digitally or audibly. I guess that would have been more accurate. Sorry for the confusion but I am not an electrician or electronics engineer. I only know what usually works for me and checking continuity often can help identify the problem. At least it has always been a good starting point for me in the past.

OK! Fluke puts out a very good product. Lab quality in most cases. Good choice.