Thread: Off the grid

The modified sine wave might be messing with the router's electronics for the 'soft start'. It clips the voltage in decreasing intervals to slowly get the motor up to speed, but if the timing works out so that the modified wave is 'off' when the router needs it to be 'on', it might throw the whole sequence out.

The techo stuff usually copes better with modified sine wave power than simple devices; apparently battery chargers are notorious for not working properly with it.

Note: I have little to no electronics experience, this is just my best guess based on some google work.

Thanks elanjacobs, much better than my best guess.

Following this lead, it might well have been possible to disable/bypass the soft-start electronics. Interestingly. routers typically have 'universal motors', that can transparently use any frequency or wave form, as well as DC! So the issue really is only the electronics, not the electrics.

Our solar installers thought the same, as did Festool. when this first happened I took it back to festool courtesy of Carba-tec, the festool folk replaced the start up electronics even though they couldn't find anything wrong (hats off to them for that). Anyway after similar problems again, they took it back.
I hope their engineers look into this conundrum and solve the issue. They could be making a lot more money, especially from remote mine sites running off large generators.
Also, as battery technology takes off, a lot of homes are going to give the grid the flick.

Mine sites (and probably any large remote installation) can well afford the extra cost of getting true sine wave inverters if they need to.

Battery tech is still a looooong way off being enough to get homes entirely off the grid. The Tesla powerwall barely has enough power to run a toaster and kettle at the same time.

Unfortunately, I think your situation is just one of those outlying cases that makes the engineers say "well that's a shame" and go back to reading the paper.

Fair point elanjacobs, although I don't think the mining companies will spend more money than they have to. Which probably means that they'll go for machinery that is more basic and does the same job. I've worked on tunnelling projects before where tools and machinery have a limited lifespan. So as long as the tool is robust and doesn't muck them around then they are happy, if it does then it will take a lot of convincing before they try out a tool that had to be returned.
As for batteries I'd say that in two years time there will be a world of difference between todays battery and future batteries.
I will add that I've been off the grid for over thirty years, I'll leave it to you to calculate the savings. Not to mention no blackouts or brownouts, and no powerlines coming down starting bushfires.

Originally Posted by HUON

As for batteries I'd say that in two years time there will be a world of difference between todays battery and future batteries.

We're still on LiIon tech from the 80s. In the past decade we've seen dozens of new battery types that promised to revolutionise the world, so far not one has become commercially available, so I'll believe it when I see it.

time will tell, but back to routers; Festool need to do something if they want more market share, dropping their prices wouldn't hurt either.

Festool products are probably a good reason for the phrase "You get what you pay for." I'm a dedicated Triton fan (and well-known for it) but I'd replace the lot with Festool if I was going to be around long enough to justify it.Their top-of-the-range router is a thing of beauty in the same way that Lamello's top model is in the biscuit-jointer field. They're fabulous, but I doubt that they have ever considered their off-the-grid performance - ever!

Ray

What happens when the router is run from a pure sine wave inverter? I heat my home in the winter (snowing as I type) with a compressed wood pellet stove. There are 3 "universal" motors in it, maybe 500W total during a loading pulse. Exhaust fan and heat exchange blower are the other two. Those motors will not run worth a dang with nearly 2X amps draw from a modified sine wave inverter. Why that is, I don't know. I only know what works with reliability. Square wave inverter and they won't even start. Only problem that I face is a need for more and expensive deep cycle batteries.
The pure sine wave inverter eats more juice to run, cost me more but it runs anything and everything ( just a little 1.2kW job) within reason when the grid goes down.

I just had a though, I wonder if you used a decent isolation transformer if that would help smooth out the bumps of a modified sine wave inverter?

I am probably no use to you, but I do have one here (I think its a 2.4kva) that I used for repairing VFD's and high powered switching power supplies. If anyone wants to test the theory I am happy to loan it out. The main issue I can see is the inverter may have trouble starting such a huge reactive load, I would imagine the inrush current for such a large transformer would be quite high.