Recent Posts

41

Renewable Energy Q&A / Re: Max winding temp

« Last post by lighthunter on August 10, 2022, 08:19:05 am »

Ha! I was way off. Looks like i need 17 in hand, 23 turns = 391 total for primary, the 120v will need 2 in hand x97 turns=194 total for 120v. Thats a total of 585 additional turns. Wonder if theres a formula for hole size required?? Seems like that will be hard to do with a 63.5mm hole.  Cross section of 14awg is 2.08mm so 585x2.08 is 1217 sq mm 63.5mm circle is 3167sqmm so it should fit. The thing is already very heavy.😁

42

Renewable Energy Q&A / Re: Max winding temp

« Last post by lighthunter on August 08, 2022, 06:21:57 pm »

Hey Pete! Am beefing this up for a friend. How many 14awg in hand for 100A, seems like 5 is right number but if i remember pj formers had more than 5 i dont wanna go too short. The original is a 2kw 120/240 and i need to lay on the low v primary and another 120 to stiffen it a bit more and make it true split phase. It should make 5kw continuous if i do it right. Yep it will b an 8010 inverter Hope you and everyone is doing well.

43

Renewable Energy Q&A / Re: Max winding temp

« Last post by lighthunter on July 25, 2022, 09:19:35 pm »

Hi all! The compressor has been behaving well with winding temps that peak around 190F 88C, i cant say it works constantly flat out at 3590rpm but it does what needs to be done.

Another question about windings, hopefully an easier one HA,  Im planning to make a large boost converter. If i use a laminated core from a toroid power transformer as an inductor, how high can i go with frequency?  Or is that totally not a good idea? Ive some E55 ferrites i could use too but im looking to get a couple kw with an 8 to 1 ratio so id likely need to parallel a few. An 8 to 1 is tough to achieve anyway and i may need to series two windings on the same core to get the lift i need at that power level so the donut just gives lots more room to do it. Thanks in advance for any ideas.

44

Product Reviews / Re: Mini Split

« Last post by dang on July 03, 2022, 10:49:39 pm »

https://ashp.neep.org/#!/

45

Renewable Energy Q&A / Re: Max winding temp

« Last post by rossw on June 29, 2022, 07:31:31 pm »

Spray drift

nowhere is safe from chemical sprays.

It can be a real problem.
I'm on a modest 22 acres. We moved here 20 years back and one of our conscious decisions has been to use mechanical and biological weed control measures - we cut and dig out blackberry roots and all, we encourage the Chrysolina beetle to control St John’s wort, slash and leave Pattersons Curse, and over-graze some areas where the sheep and alpacas can control nuisance weeds.
The amount of bird life here has increased by an order of magnitude both in diversity and quantity, we have heaps of frogs and lizards and other critters that were virtually absent when we got here, and lots of sensitive native flora like various insectivorous plants, kangaroo grasses etc are re-establishing.

We have neighbours who still choose to spray poisons around, and the council, but all are well aware of our concerns and "organic" status and most do actually make a decent effort to ensure we get no spray drift.

46

Renewable Energy Q&A / Re: Max winding temp

« Last post by Pete on June 29, 2022, 06:53:22 pm »

Spray drift eh. I was talking to a beekeeper years back and he was totally confused because he lost something like 100 hives and could not work out what caused it.
I asked him where they were and if there were any tree plantations nearby. He told me and I knew his problem straight away.
Spray drift from the plantations was it.
The plantations were sprayed regularly with a chemical called Alphacypermethrin. It is used to kill the eucalypt beetles that eat the trees.
Well as we know if it kills one insect it kills them all and the bees were not far from the plantations.
I had a friend who had his whole crop of Flowers that he had been selectively breeding for 20 years wiped out by the farmer next door spraying 2-4-D.
The farmer denied it but also happens to run a dairy and has a well frequented cheese factory. Unfortunately for my friend and his 20 year Hellebore  program the farmer was from a rich family with political connections and nothing was done about the spray drift.
Our state claims to be a Clean Green state, but nowhere is safe from chemical sprays.
Glad the documents are helping and hope the problem with the motor stays fixed
Pete

47

Renewable Energy Q&A / Re: Max winding temp

« Last post by rossw on June 26, 2022, 03:41:49 am »

Crops are doin great

Hah, you're lucky.
Where I am, the *WEEDS* are doin' great. Other things ok, but weeds are going bonkers!

48

Product Reviews / Re: Mini Split

« Last post by lighthunter on June 25, 2022, 09:57:30 pm »

So, weve added two more of these units to the house. Now the solar panels can heat or cool the house and the garage for very low cost and the solar takes care of most if not all of the day use. The two 9ks were installed in march i think. The calculated usage to cool the house in 90F weather is about 315 kwh per month. Thats under $30usd/mo at our rates, much less with solar. With 7kw of solar one 3kw array doesnt even turn on when its sunny. These last two models are hyperheats wheras the first one was just the plain version. If anyone is confused about all the seers, hspfs, eers, 9k, 12k etc, there are so many things to consider, just go to a website called NEEP. Its like AHRI but way better. These guys do tests and record data for you to see. The COP heating performance at 5° tells the story. So any machine that can get close to 2.0 COP at 5° is very efficient at heating. The hyperheat version isnt necessarily more efficient, but it can hold the btu heat capacity output at 5° wheras the nonhyper models decline to 50% btu output at that temp. Colder than 5°F they will continue to decline output but hypers will just produce more heat at that temp and also use more electricnpower to do it, so long as COP stays above 1.5 or so its still a win. Ive been exposed to several brands now and ive not seen or heard of anyone that had a problem. Not sayin it couldnt happen but seems like a mature product, they have it figured out how to build em. Im not the kind to spend a lot on things. They dont give the things away but they werent too bad either if you put them in yourself. No higher cost than any other heating system and this does both. Its just such a great compliment to solar.
We are very happy so far. Cleaning cotton fuzz from radiators with garden hose has been only maint so far. The two 9ks are usually running 1.3 to 2.5 amps 240AC during the 90 degree weather.

49

Renewable Energy Q&A / Re: Max winding temp

« Last post by lighthunter on June 25, 2022, 07:05:10 pm »

Hey Pete, that Heco document is wonderful.  We still have no email service where i work so have not gotten info on winding class yet. Because the alarm temp control i put in only has a max setting of like 209F thats what i set it to. It runs at about 185°F so am real happy with it now. The motor current at 60 hz 3600ish rpm is 200A, nameplate is 166A, thats a bit concerning but it doesnt have to run there very often.
Again that heco document is better than any i had found on the subject.

 The heat here is crazy lately like near 100 with high humidity but it rained last night so its been nice today. Crops are doin great. Its hard to make it through June without your garden being wiped out by drifting farm chemicals but this year is a bit better, lost some peppers but the rest pulled through. Even the apple trees have leaves still looking like a leaf rather than the gnarled curled shape they usually get from sprays. Ha for years i thought it was cedar apple rust until i finally caught on to it. Hope everyone is doing well!

50

Renewable Energy Q&A / Re: Max winding temp

« Last post by Pete on June 15, 2022, 05:42:10 pm »

Hi Lh, well that was a novel solution.
Here is a link to a page about winding insulation temperature ratings.
A H class winding will have White Nomex slot insulation. The rest of the insulation will be mica or fibreglass for phase insulation and leads.
Pity that Siemens pack the motors windings in too tight and fit too big a motor into a small frame.
Gone are the days where open frame motors could be run at double their ratings. Nowadays the ratings are absolute max.
I hope you are well and that the workaround stays working.
I guess some sort of air dryer like spray painting sets have could work but sounds like you are putting a lot of air into the motor.
Cheers
pete
https://www.hecoinc.com/blog/electric-motor-insulation-class-what-is-it