I picked up an antique Homelite 120 volt DC generator yesterday. The whole rig looks to be complete minus a cord to pull start it with. The guy said he wasn't sure if it ran or not and I haven't had a chance to do anything to it yet. If I do get it running, what would I be able to use it for?
What to do with an antique 120volt DC generator?
- Thread starter 55Test
- Start date
- Status
Would be good for lights. Some equipment with internal rectifiers would probably work too. Problem is there's a lot of equipment I'm sure would get fried by it, too, so I would say it would be safe for lights. Simple heaters, too, stuff like that.
Originally Posted By: RiceCake
Would be good for lights. Some equipment with internal rectifiers would probably work too. Problem is there's a lot of equipment I'm sure would get fried by it, too, so I would say it would be safe for lights. Simple heaters, too, stuff like that.
As long as the simple heater did not have an AC fan.
Would be good for lights. Some equipment with internal rectifiers would probably work too. Problem is there's a lot of equipment I'm sure would get fried by it, too, so I would say it would be safe for lights. Simple heaters, too, stuff like that.
As long as the simple heater did not have an AC fan.
JHZR2
Staff member
120V DC Generator? you sure?
I don't know the model number, it looks to be worn off of the tag. I just typed in 'old homelite generator' on Youtube and saw a few videos of Homelite generators that look quite a bit like the one I have, and the people who made those videos say it's a DC generator. I suppose if I could get the model number, I'd know for sure.
I have a friend that still using a kohler light unit, four cylinder flathead liquid cooled 4hp, 1500watt, 120volt dc.
Ken
Ken
Some lights won't be compatible with DC. No traditional florescents, no sodium vapor, i.e. basically nothing with a transformer or ballast. Some of the compact florescent and LEDs might be OK, others not OK. All tungsten will be fine.
Last edited:
Power your plain (non LED) Christmas lights.
Until a couple of years ago ConEd (NYC) use to also supply some older buildings in NYC with DC power. Mainly for elevator motors I believe. They still supply steam in addition to electricity.
Until a couple of years ago ConEd (NYC) use to also supply some older buildings in NYC with DC power. Mainly for elevator motors I believe. They still supply steam in addition to electricity.
Originally Posted By: JHZR2
120V DC Generator? you sure?
In New York (I think) there was an entire city block that used DC electricity up until a few years ago (2007).
http://cityroom.blogs.nytimes.com/2007/11/14/off-goes-the-power-current-started-by-thomas-edison/
You might be able to connect some type of square sine wave generator to the DC generator. You could look for an old UPS (uninterpretable power supply) that converts DC battery to sine wave AC current and use the circuitry.
120V DC Generator? you sure?
In New York (I think) there was an entire city block that used DC electricity up until a few years ago (2007).
http://cityroom.blogs.nytimes.com/2007/11/14/off-goes-the-power-current-started-by-thomas-edison/
You might be able to connect some type of square sine wave generator to the DC generator. You could look for an old UPS (uninterpretable power supply) that converts DC battery to sine wave AC current and use the circuitry.
Those of us who remember the old "America"s Sweetheaart" AC - DC five tube radios recall they would only work on DC with the plug insewrted the proper way for correct polarity. The DC systems in New York go back to Edison and the battle with Westinghouse.
JHZR2
Staff member
Yes, DC still was used in NYC and all that. But for the common homeowner, running common store-bought applicances and using a generator for what they use generators for, 120VDC is an uncommon supply voltage, to me at least.
>60VDC goes through the skin's dielectric so you will be electrocuted and clamped in one position.
12VDC is a common one because of vehicle accessories
120VAC is of course our normal power.
Im not denying that one could notionally make a 120VDC generator, and there may be some positive sides to it... But it strikes me as far more of a specialty item than something that a manufacturer like Homelite would sell.
More of a surprise to me than anything.... Be careful.
>60VDC goes through the skin's dielectric so you will be electrocuted and clamped in one position.
12VDC is a common one because of vehicle accessories
120VAC is of course our normal power.
Im not denying that one could notionally make a 120VDC generator, and there may be some positive sides to it... But it strikes me as far more of a specialty item than something that a manufacturer like Homelite would sell.
More of a surprise to me than anything.... Be careful.
The history channel recently had a piece about Edison's DC vs Tesla's AC. Edison was backed by the second generation Morgan, and Tesla was backed by Westinghouse.
There was some history between Edison and Tesla that was not shown in detail in the history channel clip, in that the younger Tesla had worked for Edison, and Edison had promised Tesla a significant sum of money (I think the figure was $50,000) a huge sum in those days, if Tesla could complete the design of a certain electrical item (I think it was a motor but I am not sure). Anyhow Tesla made the item and Edison reigned on the promise saying something like " you have to learn when I am joking". This resulted in Tesla quitting his job with Edison and taking a job as a ditch digger. Also interesting that while Tesla was working for Edison he dabbled in his design of an AC motor. Edison told Tesla that DC was the way to design things, and that AC was not the way to do it.
Tesla end up being backed by Westinghouse. Then Westinghouse had trouble getting investors because of the large royalties due Tesla for his designs. Tesla gave away the right to the royalties to Westinghouse so there were no longer any road-blocks to Westinghouse getting investors to get those inventions into production.
Since New York City is where this battle between Edison and Tesla took place, there is a very good chance (though I do not have any thing to prove it) that the DC block of buildings was a left over from Edison and the application of his work.
There was some history between Edison and Tesla that was not shown in detail in the history channel clip, in that the younger Tesla had worked for Edison, and Edison had promised Tesla a significant sum of money (I think the figure was $50,000) a huge sum in those days, if Tesla could complete the design of a certain electrical item (I think it was a motor but I am not sure). Anyhow Tesla made the item and Edison reigned on the promise saying something like " you have to learn when I am joking". This resulted in Tesla quitting his job with Edison and taking a job as a ditch digger. Also interesting that while Tesla was working for Edison he dabbled in his design of an AC motor. Edison told Tesla that DC was the way to design things, and that AC was not the way to do it.
Tesla end up being backed by Westinghouse. Then Westinghouse had trouble getting investors because of the large royalties due Tesla for his designs. Tesla gave away the right to the royalties to Westinghouse so there were no longer any road-blocks to Westinghouse getting investors to get those inventions into production.
Since New York City is where this battle between Edison and Tesla took place, there is a very good chance (though I do not have any thing to prove it) that the DC block of buildings was a left over from Edison and the application of his work.
JHZR2
Staff member
Sounds about right. Edison was pretty bad to Tesla in some of the stories. An electrocuted elephant in an AC vs DC movie also comes to mind from this.
But I'm still confused why anyone would want a 120vdc generator made by homelite. It's not like its an industrial thing, and there just aren't many 120vdc loads.
But I'm still confused why anyone would want a 120vdc generator made by homelite. It's not like its an industrial thing, and there just aren't many 120vdc loads.
Many of the larger electric substations with big high-voltage breakers and big transformers, use a bank made of 60 huge wet cells. At 2 volts per cell, that bank of batteries makes 120 DC. Each of those wet cells are huge. Just a rough guess but I would say that each cell weighs about 300 to 400 pounds.
When the substation is opening and closing the huge high voltage breakers during power outages like during a thunderstorm, the 120 Volt DC bank of batteries supplies power for the breakers, and all the electric controls within the sub-station. Usually the breakers are powered directly from the 120 DC, and much of the controls withing the substation are also powered directly by 120 DC, though if required an inverter that converts 120 DC to 120 AC can be used.
However I do not recall ever seeing any gasoline powered 120 DC generators at any of those substations. The 120 DC bank of batteries is on constant trickle charge from a charger powered by 120 AC when the substation is in normal operation.
When the substation is opening and closing the huge high voltage breakers during power outages like during a thunderstorm, the 120 Volt DC bank of batteries supplies power for the breakers, and all the electric controls within the sub-station. Usually the breakers are powered directly from the 120 DC, and much of the controls withing the substation are also powered directly by 120 DC, though if required an inverter that converts 120 DC to 120 AC can be used.
However I do not recall ever seeing any gasoline powered 120 DC generators at any of those substations. The 120 DC bank of batteries is on constant trickle charge from a charger powered by 120 AC when the substation is in normal operation.
Jim is that still true today? pretty cool. I recall the local telco where I grew up had a gymnasium-sized room filled with wet cells, each cell about the size of a 7 gallon bucket. It was impressive.
Can you imagine a 3.5HP gennie trying to recharge a 3,600AH 120V pack?
Can you imagine a 3.5HP gennie trying to recharge a 3,600AH 120V pack?
It has been a few years since I have been in those sub-stations, but as far as I know they are still using the same design.
One interesting history about these batteries is that while these huge batteries have an amazing long life expectancy (something like 20 years) there is a limit to how long they last. In general the rule of thumb is supposed to be that when one cell goes bad replace it and take note of it, but when a second cell goes bad replace the entire pack.
The interesting history is that in one of the sub-stations in the North Hills of Pittsburgh many years ago the pack was requiring distilled water to be added to several of the cells at a rate that was alarming, and some cells had been replaced. The person in charge of the crew that among many other jobs also maintained these batteries, had put in a request to have these batteries replaced, but the people who controlled how the money was spent did not OK the spending. So he put in another request along with stronger language about how important these batteries were, and it still was not approved. This request and rejection went on each month. Then one day there was a storm and of course as often happens during a storm a fault on one of the main lines caused a huge surge in power being drawn. The breaker (thing something about the size of a refrigerator) tripped, and as usual after the breaker is tripped sectionalizers that can not break fault current but can open the circuit once no power is flowing, sectioned off some of the line, then the breaker closed to pick up the line and see if the fault was still on the line. The fault was still on the line. Normally the breaker at the substation would of opened again, and then additional sectionalizers would disconnect more section of the line and the circuit breaker would close to try to bring up the line again. However the battery back failed (one of the cells failed open) and therefore the breaker in the substation would not open again. The fault was still on the line, and with the huge current flowing (think the equivalent power of several diesel locomotives at full throttle) the big electric buss bars in the sub-station began to melt, the huge insulators were over heated inside where the conductors were and began to explode, and the huge transformers began to melt internally.
If someone would of been in the substation yard there life would of been in jeopardy because the insulators exploded like grenades, and the bus bars melted down. When other sub-stations finally dropped the load, six of the seven transformers costing about one-million-dollars each, were damaged beyond repair.
The North hills had to put up with rotating blackout for weeks while these transformers, breakers, buss-bars, and batteries were replaced.
They tried to go after the foreman in charge of the group that maintained those batteries. He provided copies of each months request for batteries to replace the entire battery pack, and the rejections he got back each month. And he was able to keep his job. AND for some reason, from then on he had no problem getting request to replace other battery pack approved, in fact the people who approved such things suggested that he replace those battery packs in all the substations that used them.
One interesting history about these batteries is that while these huge batteries have an amazing long life expectancy (something like 20 years) there is a limit to how long they last. In general the rule of thumb is supposed to be that when one cell goes bad replace it and take note of it, but when a second cell goes bad replace the entire pack.
The interesting history is that in one of the sub-stations in the North Hills of Pittsburgh many years ago the pack was requiring distilled water to be added to several of the cells at a rate that was alarming, and some cells had been replaced. The person in charge of the crew that among many other jobs also maintained these batteries, had put in a request to have these batteries replaced, but the people who controlled how the money was spent did not OK the spending. So he put in another request along with stronger language about how important these batteries were, and it still was not approved. This request and rejection went on each month. Then one day there was a storm and of course as often happens during a storm a fault on one of the main lines caused a huge surge in power being drawn. The breaker (thing something about the size of a refrigerator) tripped, and as usual after the breaker is tripped sectionalizers that can not break fault current but can open the circuit once no power is flowing, sectioned off some of the line, then the breaker closed to pick up the line and see if the fault was still on the line. The fault was still on the line. Normally the breaker at the substation would of opened again, and then additional sectionalizers would disconnect more section of the line and the circuit breaker would close to try to bring up the line again. However the battery back failed (one of the cells failed open) and therefore the breaker in the substation would not open again. The fault was still on the line, and with the huge current flowing (think the equivalent power of several diesel locomotives at full throttle) the big electric buss bars in the sub-station began to melt, the huge insulators were over heated inside where the conductors were and began to explode, and the huge transformers began to melt internally.
If someone would of been in the substation yard there life would of been in jeopardy because the insulators exploded like grenades, and the bus bars melted down. When other sub-stations finally dropped the load, six of the seven transformers costing about one-million-dollars each, were damaged beyond repair.
The North hills had to put up with rotating blackout for weeks while these transformers, breakers, buss-bars, and batteries were replaced.
They tried to go after the foreman in charge of the group that maintained those batteries. He provided copies of each months request for batteries to replace the entire battery pack, and the rejections he got back each month. And he was able to keep his job. AND for some reason, from then on he had no problem getting request to replace other battery pack approved, in fact the people who approved such things suggested that he replace those battery packs in all the substations that used them.
Originally Posted By: JimPghPA
Many of the larger electric substations with big high-voltage breakers and big transformers, use a bank made of 60 huge wet cells. At 2 volts per cell, that bank of batteries makes 120 DC. Each of those wet cells are huge. Just a rough guess but I would say that each cell weighs about 300 to 400 pounds.
All of our switchgear buildings at the plant I work at have that for power to some of the main breakers. I don't know how many individual batteries there are in one bank, but each bank takes up about ~4ft by ~20ft rectangles and have vent hoods over the top. They do last an incredibly long time, but are kept nice temperature controlled environments.
Regardless, 120VDC is scary. I know years ago I used to work in a test shop where we had to test high voltage DC (back up power) lube-oil pumps for turbine skids. We had a whole test rig setup with piping and a massive in the floor heated oil sump. The wiring and how we controlled the RPMs of the motors was different. I wish I remembered.
Joel
Many of the larger electric substations with big high-voltage breakers and big transformers, use a bank made of 60 huge wet cells. At 2 volts per cell, that bank of batteries makes 120 DC. Each of those wet cells are huge. Just a rough guess but I would say that each cell weighs about 300 to 400 pounds.
All of our switchgear buildings at the plant I work at have that for power to some of the main breakers. I don't know how many individual batteries there are in one bank, but each bank takes up about ~4ft by ~20ft rectangles and have vent hoods over the top. They do last an incredibly long time, but are kept nice temperature controlled environments.
Regardless, 120VDC is scary. I know years ago I used to work in a test shop where we had to test high voltage DC (back up power) lube-oil pumps for turbine skids. We had a whole test rig setup with piping and a massive in the floor heated oil sump. The wiring and how we controlled the RPMs of the motors was different. I wish I remembered.
Joel
ok that is both fascinating and scary. big power is not to be messed around with.
i wonder if that failure mode in the substation systems was ever dreamt up by the design engineers. It's a perfect cascade of failures with a catastrophic end. Ugly. Also suggests either an unforseen failure mode, or a gross disconnect between decision policy and technical/safety requirements. Fascinating, and I don't wish to be anywhere near it!!
A lot of those open-cell batteries can actually be drained and dismantled for manual cleaning, extending their years. Old cells can sometimes be purchased as scrap, and rehab'ed by folks that like to live off-grid. Simple, simple technology.
thanks for the story!
M
i wonder if that failure mode in the substation systems was ever dreamt up by the design engineers. It's a perfect cascade of failures with a catastrophic end. Ugly. Also suggests either an unforseen failure mode, or a gross disconnect between decision policy and technical/safety requirements. Fascinating, and I don't wish to be anywhere near it!!
A lot of those open-cell batteries can actually be drained and dismantled for manual cleaning, extending their years. Old cells can sometimes be purchased as scrap, and rehab'ed by folks that like to live off-grid. Simple, simple technology.
M
- Status
Similar threads
