Weather Warning for Hobby Machines

[Russell EberhardtParticipant @russelleberhardt48058]

There seems to still be a bit of confusion over what surge protectors and UPSs do.

Surge protectors, such as those sold in DIY shops to protect computers etc., are designed to protect against very short term surges. They use a semiconductor device called a varistor or VDR which will typically clamp the voltage at 650 to 700 V. They can absorb currents of thousands of amps but only for a few microseconds. They will definitely not protect against the overvoltage that occurs when for example the neutral is high resistance or open circuit at the substation. They will give a certain amount of protection against damage caused by lightning induced surges.

UPSs come in various forms. The simplest do not protect against overvoltage at all they only provide standby power. More sophisticated units are available that also give voltage regulation using a tapped transformer.

Having said that, I have had one of Ketan's SX2P mills for a couple of years and it is plugged into the mains nearly all the time. I have had no problems despite living in an area with a high incidence of thunderstorms and having had a strike within 100 m of the house which took out a computer and a router. However this area is very dry and I have never suffered from condensation in the workshop.

Russell.

[Gordon WParticipant @gordonw]

Would it be worth copying an old idea on modern control systems, ie. drill a small hole at the bottom of the enclosure to let moisture out ? Used to be common practice and worked, maybe modern stuff is too sophisticated, just like me.

[MuzzerParticipant @muzzer]

I've fitted data loggers to troublesome sites in different countries where industrial battery chargers were showing high incidences of overvoltage failure. These included Chinese building sites and exposed US golf courses etc where you tend to see large load transients and frequent lightening strikes – you don't get a lot more hostile in terms of environments. Almost invariably, the problems were down to poor infrastructure ie loose connections or in some cases connecting between phases rather than from phase to neutral.

You couldn't (shouldn't) design all products to withstand those conditions (or even worse, continue to operate) without an unrealistic and uncompetitive cost penalty. There is no call for such robustness – I know, having explored it with major OEM suppliers who carry the can for warranty costs.

By law, electrical equipment is supposed to be designed to withstand a variety of transient conditions but like a lot of products, there are good manufacturers (product developers) and poor ones. Having "benchmarked" a wide variety of products, I can attest to the fact that despite the legislation, there are some pretty fragile products out there. It isn't just a question of cost, as you can design to very low cost and still meet the field requirements.

The answer is to buy stuff that matters from reputable sources – suppliers that value their customers' safety and satisfaction – rather than from unnamed hawkers behind unknown shopfronts. There is a good variety of reputable suppliers advertising (and participating) on this site!

Murray

[MuzzerParticipant @muzzer]

Valve regulation (VRLA) isn't a protection mechanism.

With a flooded battery, any overcharging results in water being electrolysed into hydrogen and oxygen and lost. You have to overcharge lead acid batteries to some degree to ensure they are completely charged and all the cells are balanced. The result is that you have to periodically water flooded batteries.

With VRLA batteries, mild, controlled overcharging doesn't produce gassing, as they are recombined and retained within the battery – and some moderate heat is generated. If the charger within the UPS isn't very sophisticated and the battery is repetitively and/or significantly overcharged, a lot more heat is generated and the battery is easily damaged. The charger would ideally identify a damaged or aged battery and stop trying to charge it.

VRLA batteries are less robust and more expensive than flooded batteries – but on the other hand don't need to be watered and won't leak if they aren't abused. That allows them to be used in home, office, hospital and food manufacturing environments for instance.

Murray

[Michael HornerParticipant @michaelhorner54327]

I have a circa 15 year old Chester mini lathe from new. It has lived in an unheated concrete garage, unheated brick garage and is now living the life of luxury in a unheated integral garage. The motor control has worked fine, even abused it by fitting a 5" 3 jaw chuck. It plays up now and again by the motor still running slowly when it is turned off for a short while.

I don't know if the controller is an american designed one but I think it has thyrister control as opposed to FET control. Not been in the electronicics box for a long time, went into tweek the pots for low speed torque etc.

Just put this in for balance.

In my job as service engineer have known smpsu costing more than a minilathe go bang. We were told it was paper dust, then brand new new machines were going pop, hmm.

Cheers Michael.

[John Stevenson 1Participant @johnstevenson1]

Personally I don't know what was wrong with the old treadle lathe.

They used to sort the men out from the boys, especially when they got over 20" centres.

[Nick_GParticipant @nick_g]

.

Lets get back to our roots.

Steam engine and line shafts to power the whole show. – Wonderful sound so no need for a workshop radio and configured correctly could heat the workshop as a bonus.

Man and machines in perfect harmony.

Nick

[Russ BParticipant @russb]

What sort of affect do you think solar power systems are having to the grid…..

During the day, I'm relatively sure my dads 4kw system produces over 1kw excess on a cold bright January day (not really sunny, just bright) – during the summer over 2kw excess is more likely.

Now, on my street, I'm one of the very few people who don't have solar, I could count but I'd guess it's about 4/5th of houses have it.

Where is all this digital sine wave, domestic voltage power going to be going, can it go back through the transformers to high voltage?

Are the sine waves all in sync?

[Neil WyattModerator @neilwyatt]

> Where is all this digital sine wave, domestic voltage power going to be going, can it go back through the transformers to high voltage?

In principle, yes.

> Are the sine waves all in sync?

Yes, that's the really clever bit of the feed-in electronics.

The latest idea is setting up local smart grids so that, on a road like yours, you can buy and sell electricity within the community cutting out the middle man so you pay less when you buy but get more when you sell. You are still connected to the grid, of course.

Another new idea is smart gear that does things like switch off the freezers and fridges when there's a surge in demand (world cup half time or Corry tea break), as 15-20 minutes of downtime doesn't adversely affect them – dynamic load balancing..

Neil

[KWILParticipant @kwil]

The other new idea in the so called smart meter era is that the consumed power is measuarble in 30 minute intervals so you can be charged variable rates at high demand periods to persuad you to switch off items.

[John Stevenson 1Participant @johnstevenson1]

The only thing smart about them is the fact that everyone who has had them fitted now pay more.

It;s the old adage : follow the money trail.

[Gordon WParticipant @gordonw]

I worry more about the big wind generators, there are dozens of them around here and a new one 1/2 mile away. What happens when they kick in ? PS very few have been running this last couple of weeks, no wind or gales.

[Clive HartlandParticipant @clivehartland94829]

Gordon, if you want to know what is going to happen to the wind generators when they kick in is see if you can look for what has happened in the USA. There in California they are spread all over the hills facing the Pacific but now after a few years are at a standstill and derelict.

It seems they found that generating wind power was not viable but being paid rent to park it in that place was! Having seen the wind generators off Herne bay all in lines but all not rotating is just an eye sore and false economy I feel, no one wants one any where near them as they emit subliminal noise which is very disturbing.

PS. They fail spectacularly, sparks and flames with bits flying around.

Clive

[Mike PooleParticipant @mikepoole82104]

I drove the length of France a couple of years ago and must have passed 600 or more wind generators, I didn't see one turning.

Mike

[John Stevenson 1Participant @johnstevenson1]

If you do see one turning, and turning slowly chances are it's being driven from the grid as these things can't be parked too long in one spot or they brinnel the bearings because the weight is so high.

Another thing is the blades have to be heated in winter to prevent ice forming and putting them out of balance.

The only way these earn money is for whoever has them parked there, again follow the money trail.

in the recent high winds they have all had to be parked up as they can't run, too dangerous.

One thing that is overlooked in this country is tidal power. Whilst the moon is in the sky we will get two tides per day, 4 in some places. And when the tide is out on the west coast it's in on the east.

One company had a lot of success with tidal generation in the Bristol Channel and approached the government for a loan to follow thru but it wasn't forth coming, all the money had been put into wind generation.

Follow the money trail.

**LINK**

So Siemens bought them out for peanuts and are making a big success of it.

Energy costs in this country would be half what they are now if no grants were paid and it's us paying the grants to people like in the link above.

[Bob Brown 1Participant @bobbrown1]

If it goes to plan and the nimby's do not get in the way **LINK**

Bob

[Gordon WParticipant @gordonw]

I don't want to start a debate on renewables. But do wonder what is happening. I am generally in favour of renewables. The new wind gen. near me is on a large potato farmer's land, all the nearby ones are on the big farms, but I am not drawing conclusions. Before the first world war a hydro power station was built in the west of Scotland to run an aluminium smelter, closed down after about 50 years, the water is still running. Seems to me it would be more reliable than wind. But I am pleased to be helping the farmers thru' my electricity bills.

[Author]

Posts