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Neil Wyatt27/05/2019 18:52:42
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Posted by Mick B1 on 03/02/2019 17:18:13:

Well, I think this is a first. I've seen offers of £2.99 down to £2.90, but nothing quite like this:-

lidloffer.jpg

The compressor and air pump are actually pretty useful, but I paid (IIRC) £19.99 for them on an intro offer when the new store opened in Leek.

You really would think that staff might actually read what they're putting up? Or do their conditions make them too cynical to bother?

I understand that pay and conditions at Aldi and Lidl are quite good and google backs this up.

N.

Hacksaw18/08/2019 20:04:46
401 forum posts
162 photos

Umm ...I've read that the electronics in mig welders dislike being run from a generator , or rather the generator needs to be a much larger kw for it to work ? Well , today i used my newish Lidls variable speed 1200w angle grinder with my Honda EX500 genny...( 500w ) It ran it ok to start with, I didn't overload it , as obviously it wasn't making much power running on 500w ..and i was only using a 1mm disc to cut off a 8mm bolt so i wanted it to keep spinning fast . When i went to cut off a second bolt , the grinder wouldn't work.. Nor on mains .. Fetching my second Lidls grinder , that worked ok with genny power and i finished the job .. Do you think i've damaged the variable speed board ? I can't see that I could have burnt out the motor windings...

not done it yet19/08/2019 07:52:19
3246 forum posts
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Posted by Hacksaw on 18/08/2019 20:04:46:

... Do you think i've damaged the variable speed board ? I can't see that I could have burnt out the motor windings...

Many modern electronics are not made with sufficient resilience - to less than perfect sine-wave supply. Particularly items with inverters included (modern welders and plasma cutters). I suspect that electrolytic capacitors won’t cut the mustard when the voltage rise time might be a bit steep or with other transient voltage spikes on the supply.

Even non-polarity conscious capacitors can be junk these days - so many old cars with Kettering ignition systems suffer with failed ‘new’ condensers. I’ve only ever had a couple or three condenser failures on my vehicles/machines and none from the 1930-50 period. I try to fit capacitors with higher voltage spec than the originals, but not always possible...

SillyOldDuffer19/08/2019 09:18:51
4595 forum posts
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Posted by Hacksaw on 18/08/2019 20:04:46:

Umm ...I've read that the electronics in mig welders dislike being run from a generator , or rather the generator needs to be a much larger kw for it to work ? Well , today i used my newish Lidls variable speed 1200w angle grinder with my Honda EX500 genny...( 500w ) It ran it ok to start with, I didn't overload it , as obviously it wasn't making much power running on 500w ..and i was only using a 1mm disc to cut off a 8mm bolt so i wanted it to keep spinning fast . When i went to cut off a second bolt , the grinder wouldn't work.. Nor on mains .. Fetching my second Lidls grinder , that worked ok with genny power and i finished the job .. Do you think i've damaged the variable speed board ? I can't see that I could have burnt out the motor windings...

Small generators are notorious for poor voltage regulation and mucky output. The waveform can be non-sinusoidal and spiky, while the output voltage swings wildly with the load. A simple generator won't be good at handling intermittent loads - like an angle grinder - and is likely to over-volt the angle-grinders electronics.

Root cause is the motor's throttle reacts too slowly, first failing to accelerate fast enough and then failing to slow down quickly when the load drops. Older generators are particularly prone to voltage swings because their regulators are slow acting, perhaps even a mechanical cut-out.

Apart from the cheap basic models, modern generators are better regulated with the posh ones putting an inverter between the generator and user to clean up the output. They still don't like being overloaded, but they're less likely to damage electronics.

An oversized generator is recommended for a varying loads like an angle grinder because the larger mass of it's spinning parts store enough inertial energy to smooth out peaks and troughs.

Dave

Samsaranda19/08/2019 10:53:13
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I had a “brilliant idea” that during power cuts I could use a portable generator to run the electrics of our gas heating system so not be without heating, wife is disabled and dreads the prospect of prolonged loss of heating during cold weather. Rigged a lead that could connect the generator positioned outside, for obvious reasons, with just the heating circuit, connected up and ran the generator, result nothing, it was at this point that I realised the output from small generators is too ragged to run sophisticated circuit boards. The generator has been relegated to a place under the bench in my workshop and awaits a prolonged power cut and it will be pressed into service to power the pumps on the filter system of my koi pond, I am sure the pumps will cope with the sine wave fluctuations.

Dave W

Nicholas Farr19/08/2019 11:20:49
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Hi, I suppose it depends on the quality of the generator and the grinder. In my last job, we used a generator on site work where there was no mains power available to run both 9" and 4 1/2" grinders, pistol drills as well as a small inverter welder, never had any issues. The grinders and drills where always 110 volts but only the drills had variable speed. The generator was a bog standard type for industrial use.

Regards Nick.

not done it yet19/08/2019 11:24:24
3246 forum posts
11 photos
Posted by SillyOldDuffer on 19/08/2019 09:18:51:
... Older generators are particularly prone to voltage swings because their regulators are slow acting, perhaps even a mechanical cut-out.
...

Not all of them! You are maybe too young to have experience with older types of generator - the current armature type rather than stator generators with an electronic AVR. smiley

My genny is a large (for domestic use) 4.5kVA Stamford armature generator driven by a Hatz E-75 (which starts black smoking at around the 3.5kW mark). Rotating armature, rather than the field, and the heavy rolled steel frame around the static field windings seems to give it much more back-up ‘grunt’ to get larger motors going and a much cleaner sinusoidal output. It was already ‘quite well-used’ when I purchased it about 40 years ago.

Perhaps not particularly large in output power, but very heavy. Only on Saturday did I start it for the first time this year. But I cannot load it into my little car (I did try). It will remain as back up should the grid go down, even though we have a disproportionate number of local feeders, due to the one particularly heavy leccy user just down the road.

Hacksaw19/08/2019 15:17:10
401 forum posts
162 photos

Well chopping the wires to the variable speed and joining them up, resulted in a still non functioning grinder !! Cable has continuity..fuse is good .. Got to go out now , i'll test the switch and windings later !

Neil Wyatt19/08/2019 15:58:04
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16435 forum posts
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Posted by Samsaranda on 19/08/2019 10:53:13:

I had a “brilliant idea” that during power cuts I could use a portable generator to run the electrics of our gas heating system so not be without heating, wife is disabled and dreads the prospect of prolonged loss of heating during cold weather. Rigged a lead that could connect the generator positioned outside, for obvious reasons, with just the heating circuit, connected up and ran the generator, result nothing, it was at this point that I realised the output from small generators is too ragged to run sophisticated circuit boards. The generator has been relegated to a place under the bench in my workshop and awaits a prolonged power cut and it will be pressed into service to power the pumps on the filter system of my koi pond, I am sure the pumps will cope with the sine wave fluctuations.

Dave W

You could get a computer UPS to power the heating. Be aware that they are probably the most unreliable bits of kit known to humanity. Alternatively a leisure battery kept topped up and the smallest inverter you can find.

not done it yet19/08/2019 16:11:37
3246 forum posts
11 photos
Posted by Neil Wyatt on 19/08/2019 15:58:04:

You could get a computer UPS to power the heating. Be aware that they are probably the most unreliable bits of kit known to humanity. Alternatively a leisure battery kept topped up and the smallest inverter you can find.

But do make sure, if you do go the leisure battery/inverter way, that you use a pure sine wave inverter - not a cheap square wave option - if there are any electronics involved. For short outages, the car battery might do if the battery was good (without having to run the engine...).

Hacksaw19/08/2019 22:03:39
401 forum posts
162 photos

The Lidl angle grinder failure .. Having bypassed the revver upper bit ..(assuming it was dead) Still it wouldn't work .. I was expecting it to run at full speed..lidls grndr 001.jpg

I checked the cable and fuse , they were ok . Spinning the motor by hand generated up to 35 volts on my cheap digi meter , so i assumed the motor was ok too .Which left the on /off switch.

lidls grndr 002.jpg

 

 

 

I wasn't going to test it with mains electric , so i flicked the tester to ohms and hooked it up to input and output.. The neutral side didn't register anything upon pulling the trigger...but the live did.. So a switch fault ?? I removed it from the housinglidls grndr 003.jpg

 

And pulled out the switch bit ...lidls grndr 004.jpg

 

I took it apart , to fix it ... it'll be a simple 2 pole ....And I'm afraid it's beyond me , as that's full of electronics stuff...!!! Soft start and quick stop circuit I suppose ? lidls grndr 005.jpg

 

Would i buy another ?  Absolutely !  I have three others and they're great .. but i won't be running them on a genny. I know i could take it back and they'd refund me, there's 2 years warranty on them but I'll keep this one for spares for the others should  I burn one out..

Edited By Hacksaw on 19/08/2019 22:28:51

vintage engineer19/08/2019 22:30:50
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156 forum posts

Have you checked the brushes? Bosch grinders have a sprung loaded pin in the brushes, when it wears down the pin pops out and lifts the brush.

Hacksaw19/08/2019 22:35:52
401 forum posts
162 photos

well it's still "new" but i did look anyway and they're fine . It's the i.c. boards i'm sure ..

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