Petrol generator damaging power tools?

[minilathe22]

Hi everyone

I am renovating a building that has no mains power connected at the moment, and I have a small petrol generator that I bought used. It can output mains 240v through a blue caravan style 16A connctor or via a switch 110v through a similar looking yellow connector.

Its almost identical to this model:
https://www.powertoolsdirect.com/clarke-pg3800a-3000w-max-petrol-generator

I have found two brand new power tools appear to have stopped working, having been used on "real" mains electricity without issue but after a few short uses on the generator they are now both dead. Fuse tested ok in the plug. Other devices still work on the generator so its not the output that has stopped. A Bosch angle grinder, and a Bosch chainsaw. Neither were the cheapest options.

When you start the power tool, you can hear the engine on the generator bog down briefly. I am wondering if some kind of power/voltage spike is being sent into the tools reducing their life? Is there any heavy duty filter I can plug inline to avoid this? Is it just a crappy generator?

 

[Katomi woodsmith]

I have the wolf version of your gen set, though mine is 3.5 kw
As others have said that the gen will dip in revs (bog down) until the tool is running at full speed. Mine has an auto throttle that cuts in and ups the revs when I start a tool.
The only probs I have had with gen set(s) is that when recharging cordless tool it’s so easy to overcharge and cook the battery as the cutout relies on an earth that gen sets don’t have
NB same problem happens on inverters sometimes.... I cooked an expensive Bosch battery by leaving it on overnight on my solar/batter/inverter system

 

[minilathe22]

I had not considered the earth connection. I have been lazy and not used it, the generator does have a mounting on the frame to attach an earth rod.

 

[macetownhouse]

Hello,
First l would find someone who knows how to read a multimeter, and check the output of generator. Some can fluctuate wildly. I have seen a few cheap one putting out huge differences.
In my option which is probably wrong a 6kv. generator is what is needed.
Power tools are two expensive to loss to a generator, maybe look at cordless.

 

[John Brown]

I have the wolf version of your gen set, though mine is 3.5 kw
As others have said that the gen will dip in revs (bog down) until the tool is running at full speed. Mine has an auto throttle that cuts in and ups the revs when I start a tool.
The only probs I have had with gen set(s) is that when recharging cordless tool it’s so easy to overcharge and cook the battery as the cutout relies on an earth that gen sets don’t have
NB same problem happens on inverters sometimes.... I cooked an expensive Bosch battery by leaving it on overnight on my solar/batter/inverter system

I've never heard of that - relying on an earth to terminate charge - as far as I knew, charge termination on Nickel cells is based on either temperature change or voltage change and on Lithium based on the current dropping below a specified level, in both cases there might also be a timer function as a belt and braces solution. I'd be intrigued to hear about the earth thing, especially as I'd swear that some of my chargers have plastic earth pins.

 

[Dabop]

I've never heard of that - relying on an earth to terminate charge - as far as I knew, charge termination on Nickel cells is based on either temperature change or voltage change and on Lithium based on the current dropping below a specified level, in both cases there might also be a timer function as a belt and braces solution. I'd be intrigued to hear about the earth thing, especially as I'd swear that some of my chargers have plastic earth pins.

That's because they don't....

In fact 99.99999% of chargers used for battery power tools use no earth at all (as they almost all use a switchmode power supply) and are in fact double insulated....

in fact switchmode PSU's are the safest option for use with inverters and generators, while mains powered motors can have some issues- predominantly involving those with variable speed controls, which are often relatively unprotected against voltage spikes- the older style single speed motor with a simple on/off switch are a better tool to use on most cheap genpacks, but really if you are using any genpack, spend the extra money and get an 'inverter generator'- they are far safer for any device....

Chargers for battery tools are almost invariably powered by a switchmode PSU (look for the 100-240v, 50/60hz label- if its got one of those, it's a switchmode) and these simply don't care how 'dirty' the power is- they can accept any voltage in their range (or even varying voltages like commonly found on smaller genpacks) of any frequency (or even straight DC!!!) or any waveform (pure sinewave, multistep modified squarewave, even a triangle wave or straight DC- a switchmode simply doesn't care lol)

As the input mains has literally no effect on the regulated voltage output being fed to the charge circuit, it has ZERO effect on the battery charging regime... so no- a generator will NOT' overcharge' your battery- it's an urban myth from 'ye olden days' of linear PSU's- which haven't been used in the last quarter of a century....

 

[woodieallen]

I've never heard of that - relying on an earth to terminate charge - as far as I knew, charge termination on Nickel cells is based on either temperature change or voltage change and on Lithium based on the current dropping below a specified level, in both cases there might also be a timer function as a belt and braces solution. I'd be intrigued to hear about the earth thing, especially as I'd swear that some of my chargers have plastic earth pins.

+1

 

[Katomi woodsmith]

Ok my tools are prob that old, I can here the gen kick now and then when tools are charged.
Yes it was on old Ni-cad battery drill that I cooked,
Ps sitting on a pontoon with a gen set using 240v drill is not safe apparently.... according to the chap who tore me a new one for being so stupid
He may of had a point the drill was starting to smoke.
Ah but there be the grace of God go I ___ saved from the stupidly of youth