It is currently 29 Mar 2024, 10:55

Generator advice please

This is the place to go with all your issues, questions or handy hints on all things related to motors, electrickery, engineering, metalwork etc...

Generator advice please

Postby AJB Temple » 21 Jul 2021, 08:33

I am considering buying a 240v generator but know little about them apart from sales pitches online.

Can anyone advise me from experience please. Domestic, not massive thing that I can tow.

Reason: in the last 6 weeks we have had three power cuts, two of which lasted 10 hours. We live 20 miles from London but the power and phone network is almost 3rd world. Yesterday we had another dramatic thunderstorm (had one the previous day too) and a terrace area which has a sump pump was overwhelmed in 15 minutes of tropical downpour.

If I get a lot of rain and a power cut together, we have a flood risk for part of the house. I also do not like having 10 or 12 hour power cuts killing all the filtration and air in the Koi pond, or having the router go down endlessly.

I am aware that you can get petrol, gas or dual fuel.
Inverter technology is more expensive for same output, but has smooth sine wave and is fine for TVs and laptops.
Some have large fuel tanks (25 litres) and will run for up to a day.
Instinctively I tend to think more capacity is better. Decent inverters can be had for £300 but limited to around 2.5Kw
Or I can get around 8.5Kw in an electric start non-inverter for about £600.
More power seems to mean more noise.
Engine reliability would seem key as use will depend on power cuts, which I hope will be infrequent.
Lack of smooth sine wave seems irrelevant for running pumps, a heater, lights etc. I can live without TV and laptop.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby SamQ aka Ah! Q! » 21 Jul 2021, 10:48

I'll add my plea to Adrian's; my situation is similar: freezer, gas heating boiler would be my priorities.

S.
A pragmatist inside a perpetual optimist, heavily influenced by an experienced cynic, wrapped around by an aging relic.
SamQ aka Ah! Q!
Old Oak
 
Posts: 1030
Joined: 21 Jul 2014, 23:06
Location: High above the Aln.
Name: Sam

Re: Generator advice please

Postby novocaine » 21 Jul 2021, 10:57

before doing anything, figure out how you are connecting in to you house network.
you will need a transfer switch that completely isolates you from the grid before the generator starts. you really really really don't want to push back to the grid out of sync. for some reason, they get annoyed about it. :lol:
Carbon fibre is just corduroy for cars.
novocaine
Old Oak
 
Posts: 2560
Joined: 26 Nov 2020, 10:37
Name: Dave

Re: Generator advice please

Postby Jonathan » 21 Jul 2021, 11:21

Adrian, for the last 16 years I've had a Honda EX10D, I bought it second hand and if I was to sell it I could probably get money back.
We are off grid and only use the generator when we get 3 or 4 days with no sun, so it's probably used 3 or 4 times a year.
I went for Honda as I knew there reliability

Noise is not a problem if you get a silenced one....friend has a cheepo petrol generator, they tend to be super noisy.

When I was in UK I had some dealings with Stephill generators, they are generator specialist and where good.....



Sent from my Redmi Note 9S using Tapatalk
Jonathan
Sapling
 
Posts: 294
Joined: 26 Jul 2017, 06:44
Name:

Re: Generator advice please

Postby 9fingers » 21 Jul 2021, 11:43

As Novocaine says, isolation from the grid connection is VITAL

Non inverter generators have to run at constant speed usually 3000 rpm for petrol & gas and 1500rpm for diesel

Inverter generators will vary the engine speed and all other sound reductions being equal, will be quieter unless run at full output and use less fuel. These are by far and away the biggest advantages of inverter generators as well as the more pure sinusoidal output

For reasons too complex to go into here, the generator rating measured in kVA, should be about 1/4 to 1/3 greater than the sum total of your appliances wattages.

If you are only going to have a few things connected to the generator, think about how you will achieve this with your existing wiring.
1) you will have to cut off the grid connection (so you won't know when the grid comes back up)
2) you will have to religiously turn off all other loads to prevent overloading the genny

NEVER NEVER EVER put a 13 amp plug on the genny and plug into a wall socket.

Alternatively have enough extension leads from the genny to the various things that need powering which will be messy but avoids all the above issues.

Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
User avatar
9fingers
Petrified Pine
 
Posts: 10039
Joined: 21 Jul 2014, 20:22
Location: Romsey Hampshire between Southampton and the New Forest
Name: Bob

Re: Generator advice please

Postby AJB Temple » 21 Jul 2021, 12:11

Thanks guys.

I am aware that a transfer switch is needed to connect to the house. That is not my plan though. I am aware that electrical sockets are not for pumping power in - but thanks for the warning as I accept this is the internet and has a few idiots.

I want to be able to plug a handful of things directly into the generator (within its load capacity obvs) not have a standby for the whole house.

So, likely candidates are: sump pumps (two) if we have rain and power goes down at the same time.
Koi pond filter and air if we have a power cut longer than say 8 hours.
Fridge/freezer if we have a long cut.
Maybe a bit of emergency lighting.
Charge phone and laptop to keep us going in an emergency.

These things can be run off my heavy duty extension leads.

Probably 3Kw output would be sufficient. Inverter technology is appealing as I like the idea of it throttling down to meet lower load, and they will run for quite a while on a single fill. Friend of mine who works for Mercedes has said get one with either Honda or Hyundai motor. Reliability is key as a dead generator is no use in an emergency.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby Woodbloke » 21 Jul 2021, 12:30

9fingers wrote:As Novocaine says, isolation from the grid connection is VITAL


If you are only going to have a few things connected to the generator, think about how you will achieve this with your existing wiring.
1) you will have to cut off the grid connection (so you won't know when the grid comes back up)
2) you will have to religiously turn off all other loads to prevent overloading the genny

NEVER NEVER EVER put a 13 amp plug on the genny and plug into a wall socket.

Alternatively have enough extension leads from the genny to the various things that need powering which will be messy but avoids all the above issues.

Bob


I have very little expertise here, but I think that Bob & Dave’s advice is to be taken seriously. Were it me, I would isolate from the incoming mains supply by simply switching a very large ‘On/Off’ switch in the consumer unit but I don’t know whether that would be sufficient.

Extension leads from the generator to all the essential items that need power would seem to be eminently sensible; in my case it would be the cooker (only using the induction hob, not sure how that could be done; we like salads though :D ), fridge/freezer, washing machine (questionable) ‘pooters, pond (uv, pump), workshop (lighting only to be used) and one or two lamps (inspection type jobbies with a cage and hook). Cold showers work well in this weather :lol: - Rob
I no longer work for Axminster Tools & Machinery.
User avatar
Woodbloke
Sequoia
 
Posts: 5866
Joined: 22 Jul 2014, 10:06
Location: Salisbury, UK
Name:

Re: Generator advice please

Postby 9fingers » 21 Jul 2021, 13:20

If you are looking at diesels Kubota and Yanmar engines (please not motors!) are good.

For petrol engines stick to 4 strokes and drain all fuel at the end of the run and empty the carb by running the engine until it stops.
Look after the battery with a smart charger and be prepared with appropriate leads to jump it off a vehicle if needed.
Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
User avatar
9fingers
Petrified Pine
 
Posts: 10039
Joined: 21 Jul 2014, 20:22
Location: Romsey Hampshire between Southampton and the New Forest
Name: Bob

Re: Generator advice please

Postby novocaine » 21 Jul 2021, 13:41

9fingers wrote:If you are looking at diesels Kubota and Yanmar engines (please not motors!) are good.

For petrol engines stick to 4 strokes and drain all fuel at the end of the run and empty the carb by running the engine until it stops.
Look after the battery with a smart charger and be prepared with appropriate leads to jump it off a vehicle if needed.
Bob

spoil sport. who doesn't love the dulcet tones of a 2 stroke Robin beating it's tinny little 2 pot in to non existence at 8k rpm.

Kubota diesel unit would be a good call, diesel tends to last for ever, especially with the current ethanol blugh.

I got shut of the big Honda 3kv unit a few years ago. I've got a tiny little clarke 700w unit for running tools away from home but it rarely gets used.
Carbon fibre is just corduroy for cars.
novocaine
Old Oak
 
Posts: 2560
Joined: 26 Nov 2020, 10:37
Name: Dave

Re: Generator advice please

Postby AJB Temple » 21 Jul 2021, 13:55

Hardly any small gens run off diesel. Obvs much cheaper as can use red.

It is both impractical and unnecessary to try to have a switchover to try to replicate the house supply, so I am not considering that in any way.

What I was really looking for is recommendations for specific gens suitable for home use. The trade offs seem to be:

High power 8Kw at sensible price£600 = erratic sine wave and consumes a lot of fuel +noisy
Inverter - quieter, efficient, will run computers etc fine, but much more expensive at circa £800 for 3.8Kw
Some claimed inverters are not really apparently
50% premium for Honda or Hyundai motor v pretend branded Chinese
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby Guineafowl21 » 21 Jul 2021, 14:00

Note that there is a difference between running a single, earthed power tool on a portable genny and running an entire house on one, where earthing is concerned. The earthing will have to be matched and depends on your existing set-up.

As above, you’ll need a break-before-make genny/mains changeover switch, and to switch off heavier, un-needed loads while it’s running.

Best thing is a laminated sheet with switch-over procedure, hung in a convenient place. Also nice to have is some means of indicating when the mains is back on, conveniently located.

Before you call in a sparky, work out exactly what appliances are needed, and so total load, and your sparky will be able to spec the genny for you, taking into account headroom, turn-on surge and power factor.

EDIT: post crossed with above.
Guineafowl21
Sapling
 
Posts: 289
Joined: 15 Dec 2020, 17:11
Location: Inverness
Name:

Re: Generator advice please

Postby novocaine » 21 Jul 2021, 14:06

treadmill? :lol:

for emergency use, as said, reliability is king. I've never had an issue with the little clarke, but it isn't for emergency use (it used to power the race trailer but if it went out it didn't matter).

depending on the length of time, i'd be tempted by UPS instead of generator. you aren't going to get 8 hours of running everything, but a couple of hours could be achieved with a dedicated battery unit and an inverter.
Carbon fibre is just corduroy for cars.
novocaine
Old Oak
 
Posts: 2560
Joined: 26 Nov 2020, 10:37
Name: Dave

Re: Generator advice please

Postby AJB Temple » 21 Jul 2021, 14:24

UPS is not viable. Computer UPS for an office set up say has a run time measured in minutes. 5 Kw wall battery UPS for a house (ie not very big output ) will cost about £8000 to install. Not worth it for me.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby 9fingers » 21 Jul 2021, 14:27

Talk to pete power here https://petepowerblog.wordpress.com/
What he does not know aint worth knowing. I bought a used 1000w Honda inverter from him for odd job use and it has been faultless.
Something like a Honda EU30is should suit your application.

Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
User avatar
9fingers
Petrified Pine
 
Posts: 10039
Joined: 21 Jul 2014, 20:22
Location: Romsey Hampshire between Southampton and the New Forest
Name: Bob

Re: Generator advice please

Postby Andyp » 21 Jul 2021, 15:02

Adrian,
Have you had an explanation form the National Grid, or whoever is responsible these days, for why you are getting so many power cuts? Is it the whole town/area or just very local to you?

Different scenario I know but we live 1km from the local village. A small hamlet of just 21 dwellings fed from one transformer type thingy at the end of the road. Like you every time we get very heavy rain we are likely to get a power cut. The village, we know, is unaffected. We have tried, admittedly without success so far, to find out why.
I do not think therefore I do not am.

cheers
Andy
User avatar
Andyp
Petrified Pine
 
Posts: 11721
Joined: 22 Jul 2014, 07:05
Location: 14860 Normandy, France
Name: Andy

Re: Generator advice please

Postby AJB Temple » 21 Jul 2021, 15:11

Bob, just PM'd you.

My search is over. Thanks muchly. Adrian

Andy: yes, the "reasons" are per Southern Power for all of the events this year. We had an inspector come to check us out as we have three high voltage line going over part of our garden.

Traveller (they actually said Pikey) hit overhead line with tipper truck and brought it down, along with pole which the repair engineer said was one of the most stupid he had ever seen) (it was a mile from us in our rural lane)
High voltage line failure (twice) 2 miles from village
Component failure in local sub station (took 12 hours to locate and rectify, affected 1200 houses and we were in the last 20 to come back on)
Network rail sub contractor accidentally cut through underground supply cable linking two pilons. This took 8 hours to fix.
Weather related incident
Person operating a digger in a field caused damage to a pole carrying a transformer.

We have several villages around here and some of them are missing their idiot.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby MattS » 21 Jul 2021, 15:28

Have you considered a renewable system with battery storage? Sure it would cost more that a generator but will reduce costs the rest of the time.

Tesla do one don't they?
MattS
Nordic Pine
 
Posts: 771
Joined: 04 Jul 2016, 10:05
Location: In the Weald of Kent
Name:

Re: Generator advice please

Postby novocaine » 21 Jul 2021, 15:31

I think you should be the test mule for the rest of us and by a hydrogen fuel cell. :D
Carbon fibre is just corduroy for cars.
novocaine
Old Oak
 
Posts: 2560
Joined: 26 Nov 2020, 10:37
Name: Dave

Re: Generator advice please

Postby AJB Temple » 21 Jul 2021, 15:38

See above re UPS Matt. Not viable.

Battery system that will connect to the house work out at about £8,000 to £10,000 for the first 5 Kw and then around £5,000 to £7,000 for each additional 5 Kw.

There is a degree of uncertainty about battery life as these systems for domestic use are still quite new.

They are reckoned to add minimally to house resale value. I think they might be viable for a properly designed new passive house, but otherwise the payback period is immense.

My ex-wife has a Tesla wall system. But she lives in Gibraltar where they can utilise ample solar and also access a wind generator. They key though is it was designed into the house which was finished a year ago and so they avoided the cost of other fuel systems being installed.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby RogerS » 21 Jul 2021, 18:21

Glad you're sorted, Adrian.

We've got a 6KVA Honda powered generator. It's noisy but does the job. I've not had call to use it as yet up here. Of course, TOAS - my neighbouring idiot of a subsidy farmer has threatened to cut off our electricity in the past.
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Generator advice please

Postby AJB Temple » 21 Jul 2021, 18:48

Cutting off your electricity might be a gift if he is stupid enough to do it. May well be a criminal matter. Expect he is just a bully full of hot air.

I've gone for a Honda GX390 with wheel set and large tank. Less than 100 hours on it, fully refurbed and serviced. Rated at 7000Kw continuous and 8750 starting. Pete describes these engines as "immortal" if the oil is changed every 100 hours.

This was the larger of two offered to me that met my needs, and I went for it because it has sufficient kick to start and run two heavy duty 2" pumps, plus Koi pumps and UV and I can if I want rig a separate supply to my kitchen building, which is easily isolated from the rest of the house (if I install the necessary switchgear) as it has two independent sub CU's (one does lighting and fish ponds and external sockets, the other does the actual kitchen appliances - so various ovens, refrigeration and induction hobs) in an emergency.

I will probably get a small inverter unit to do computers as well, which we can also use on a boat.

I've learnt a lot and Pete was very helpful indeed. Sent me useful stuff and lots of advice.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby RogerS » 21 Jul 2021, 21:39

AJB Temple wrote:.... May well be a criminal matter. ...

...


It is. I ring the police, get a crime number then give it to NorthernPowergrid who then take over. Job done.
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Generator advice please

Postby Dalboy » 22 Jul 2021, 09:12

I know that older generators produce what we called dirty electricity which mans that they are not suitable to run sensitive equipment with circuit boards. They were really designed for site work things may have changed since i was working in the tool hire business.
Dalboy
Old Oak
 
Posts: 1267
Joined: 29 Aug 2014, 11:16
Name:

Re: Generator advice please

Postby AJB Temple » 22 Jul 2021, 10:01

It is still true. But my main requirement by far is running pumps.
Don't like: wood, engines, electrickery, decorating, tiling, laying stone, plumbing, gardening or any kind of DIY. Not wild about spiders either.
User avatar
AJB Temple
Sequoia
 
Posts: 5433
Joined: 15 Apr 2019, 09:04
Name:

Re: Generator advice please

Postby Andyp » 22 Jul 2021, 10:42

Anyone like to explain dirty lecky? And can it be cleaned for aforementioned sensitive equipment?

At I guess I would imagine that TVs would be classed as sensitive.
I do not think therefore I do not am.

cheers
Andy
User avatar
Andyp
Petrified Pine
 
Posts: 11721
Joined: 22 Jul 2014, 07:05
Location: 14860 Normandy, France
Name: Andy

Next

Return to Engineering - Electrical/Metalworking

Who is online

Users browsing this forum: No registered users and 3 guests