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Author Topic: Voltage drop under load  (Read 18123 times)

guest23837

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Re: Voltage drop under load
« Reply #75 on: October 20, 2018, 12:25:14 AM »
>  is there any way to determine the uf rating on these

Capacitor meters.  Been around for years, and they should be more than enough to measure the cap.

Just remember, it may leave a charge on the cap, which can "bite" - sometimes fately .  Be careful.

hi Mike
I figured out how to use the meter its says 36uf the voltage is a little low at 200 volts. The alternator has been sitting for a while maybe the capacitor needs a bit of work? maybe its goosed? I was going to speed up the engine by 150 rpm but i might lose the frequency ???
Paul

guest23837

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Re: Voltage drop under load
« Reply #76 on: October 20, 2018, 08:18:27 AM »
Thanks glort. The capacitor fits inside the end cover is it possible to have 2 capacitors mounted outside? I didn't measure the frequency on this it was quite good on the last alternator and I didn't change the engine speed. I have several capacitors from previous experiments so a 20+15 uf wired in parallel could work? If there was a little more power then I can order a new capacitor that fits properly? My lights and TV would work on 200 volts anyway I think? Another question! There is no data label on the alternator is there a way to calculate the total output? The alternator fits on to the engine but it's shorter by over an inch.

guest23837

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Re: Voltage drop under load
« Reply #77 on: October 20, 2018, 05:13:04 PM »
Hey Glort
Again many thanks for your wise and useful input. These are the readings I'm getting with a 25 uf & 20 uf capacitor wired in parallel. The voltage does fluctuate by 2 or 3 volts but I'm happy with what it is for small money.  Photos attached.

guest23837

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Re: Voltage drop under load
« Reply #78 on: October 21, 2018, 08:55:29 AM »
thats 50 HZ mate

guest23837

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Re: Voltage drop under load
« Reply #79 on: October 21, 2018, 10:37:35 AM »
We have a nominal 230v power here. A lot of the electrical stuff comes from the UK and they use 240v -6% to +10%. The system of  230V +/-10% that is used in Ireland is pretty much the same. It was something to do with harmonising power supply across Europe. Usually only businesses here have 3 phase 415 volts supply. I have to do some tidying of wires today get it earthed and so on. I was going to speed up the engine to 3600 with the original capacitor to see if it was designed to run at a higher speed but then the frequency would be off. There should be a 5uf capacitor somewhere I could add but I think its ok as is. The cheapness appeals to me as well!

EdDee

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Re: Voltage drop under load
« Reply #80 on: October 21, 2018, 10:38:22 PM »
For my need it in a hurry with max output gennies, I set rpm to between 60 to 63hz, volts to 240... These are the little portables that I lug round the plot to do the odd bit of electrical needed in a remote corner type work... they seldom run more than an hour or two at a time, but are run hard...

The bigger, less portable standby units, I normally clock to 51hz unloaded, 230V, and they run at a lower percentage of total output, but much, much longer periods....

Both ways they seem to last well... but to run hot and fast and heavy for long ain't a good idea in my book....

Cheers
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
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guest23837

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Re: Voltage drop under load
« Reply #81 on: October 21, 2018, 10:45:56 PM »
For my need it in a hurry with max output gennies, I set rpm to between 60 to 63hz, volts to 240... These are the little portables that I lug round the plot to do the odd bit of electrical needed in a remote corner type work... they seldom run more than an hour or two at a time, but are run hard...

The bigger, less portable standby units, I normally clock to 51hz unloaded, 230V, and they run at a lower percentage of total output, but much, much longer periods....

Both ways they seem to last well... but to run hot and fast and heavy for long ain't a good idea in my book....

Cheers
Ed
Hi Ed
Thanks for the info all this stuff is stored for future reference, I will speed it up slightly tomorrow only need 60 more rpm. Power was off for an hour this evening and I ran a few lights and the television off it, wife didn't complain about flicker either. Now a question Ed do you know how I could find out the total output of the alternator using a multi-meter?
Thanks
Paul

EdDee

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Re: Voltage drop under load
« Reply #82 on: October 23, 2018, 12:56:09 PM »
Hey JD,

Not easy.... Need 2... one measuring current, the other voltage....Multiply the readings to get VA.... add up your totals every second or two, do it for an hour, you get KWH ....

Or....

Buy a cheapie VA meter off fleabay and throw away the pencil!

Cheers
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

EdDee

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Re: Voltage drop under load
« Reply #83 on: October 23, 2018, 03:41:24 PM »
Yep, that's pretty much it.... Load to start of black, make note of V/A/Kw.... Load to start of blue, note same..... A quick look at the exhaust emissions from a distance tells you approx how hard its running....except at night.....then you can only tell if its running hard if the exhaust glows orange....

Lol
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

guest23837

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Re: Voltage drop under load
« Reply #84 on: October 24, 2018, 09:55:34 AM »
Thanks Glort more stuff to think about more toys for me! I was looking at a Robin EY20 generator yesterday needs some work but interesting if I can get it cheap. I know I dont need it but I never had a Robin engine before something to play with over the winter.

guest23837

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Re: Voltage drop under load
« Reply #85 on: October 24, 2018, 11:02:22 AM »
Thats splendid news about the Robin. Seller said he put a new carb on it but it needs "adjustment" I checked and new carbs are pretty cheap and readily available. Of course people attempt repairs on things they shouldn't touch so if I get it might be a simple fix. Glort you repaired lawnmowers I sometimes buy them in winter and do them up, its a little source of income. The amount of mowers with the carb gummed up and all the little springs missing on the carburettor linkage is amazing. These simple engines are a big challenge for some people.

ajaffa1

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Re: Voltage drop under load
« Reply #86 on: October 24, 2018, 12:58:21 PM »
Hey Glort, there is still money to be made in servicing small engines. There is a company in Hongkong called Farmertek, they make very good reproduction parts for Stihl and Husqvarna machinery. A new cylinder, piston, crankshaft, all the gaskets and etc for a 48 cc chainsaw was under $100 delivered. Replacement chainsaw around $1000

Bob

guest23837

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Re: Voltage drop under load
« Reply #87 on: October 24, 2018, 01:12:37 PM »
I always find myself strangely attracted to Briggs side valve engines! Good Honda lawnmower engines are easy to get probably because the frames are rotten, nobody ever cleans them and they rust from underneath. The engines don't fit the aluminium mower bodies that the Briggs engines fit. My mower is a really old CastelGarden with an old Briggs Quantum side valve engine. It needs valve stem oil seals this last 5 years poor compression and smokey I really have to fix it for next year. It's got the wrong carburettor and cables made from old bicycle brake cables. You'd never see a 2 stroke mower here apart from on a hover mower. I know the Briggs OHV engines are crap so Im now on the hunt for a 5hp Quantum side valve