Genset

you wont get very far with a system of discombobulated devices such as this.

How on earth is Hobart 800 amp Pipeliner welding machine a discombobulated device??

Second as an industrial tech I can assure you your peak load power levels are way past what a set of 48 volt 1000 amp cat batteries and any type of synchronous inverter you could possibly ever afford let alone synchronized to a mere 1500 watt base reference point will handle or work with.

Your understanding fails on this point again. The hobart welder can produce 200 amps per person and you will have 250 amp surge (1000 /4 )protection. That is 450amps. What on earth do you need to weld with 450amps. Per person?? The hobart machine is already designed for two welder capable of air arcing at 400 amps each.
Most welders (guys) have an 80 % efficiency rating. That means four guys will use a potential of 1800 combined amps ( battery and welder). 80% of the time So at an average of 120 amps x4 = 480 amps x 80% = 384 amps leaving 1416 amps for welding surge and/or auxiliary inverted power. You can weld with a car battery and an alternator so why would you have trouble with this? Besides 48 volts is more that you need. Dialed in at 36 volts that leaves you right there with 25% more voltage power.
I've already told u, I do not need to synchronize the inverter any more. U do not seem to be able to grasp that idea.
1000 amps translates to 100 amps of inverted ac power. No grid no exciter NO SYCRONIZER and that is very affordable. Ive already stated ...on ng power at 5.00 gj what's the problem?

For one the peak AC load demands being supplemented by a set of batteries and an inverter concept you are way off on your numbers in so many ways it bothers me.

How on earth can 4 guys use more than 100 amps of ac inverted power when they are welding 80% of the time. ??

To be honest if it was me trying this I would set up one dedicated welding station ran solely off of a stock NG fueled engine driven welder and see what the realistic operating costs plus inconveniences add up to for a month.

Like I said these are rough numbers. If my Hobart is designed for 2x400amps why can't it work 4x200 amps. Even if you realize 120amp has a margin of 80 amps extra. Further reduced by 80%=96amp usage. That leaves you with 104 amp extra with out the batteries. Add the surge protection of batteries 1000 amps divide by the unlikely hood all 4 guys all needing the surge protection at the same time , =1000divided by 4 is 250 plus the extra 104 amps, it is very unlikely all four guys will use all 354amps each all at the same time. This leaves lots of surge protection and power for the inverted ac off of the batteries. Does that not make sense?

When you are not using the full output of the co gen system the meter does run back wards but when you use more power than your co gen system produces the meter runs forward taking that power back you put on it earlier just like charging and discharging a battery but its being done with your full three phase AC power system

I understood you would need some pretty expensive switches in case the grid goes down and it's not easy to get commissioned to do that.

all the complicated batteries, inverters, control systems and what not costing you more operating money and loosing overall system efficiency.

That's the beauty of my system it is very simple, all you need is an inverter and 4 cat batteries. Ng is so cheap the loss of efficiency from the batteries (30 40% is more than compensated for with 200,000 btu of hot water. The coefficient of performance supplements any losses.
Thanks
H.

The history of the Hobart Pipeliner is that 4 of these machines would be jackshafted powered and mounted on a d9 and eight guys would all be welding at the same time. Sure as **** it wasn't discombobulated then when all were burning 1/4 inch rod for a pressure weld on a 72 inch line. Lol

It would appear that you are leaving out a lot of details on the whole concept. A Hobart 800 running as a dual output welder system for welding purposes works just fine and is not the discombobulated part of the system I am talking about.

The discombobulated part is the using the welder generator to charge a set of batteries to further drive a very big inverter to supply the 480 volts AC while still functioning as a welder is.

A 48 kilowatt inverter that changes 48 volt DC into 480 volt AC output is not a cheap unit plus that 100 amps at 480 volts is still single phase where as most large devices that need a 480 volt input take three phase.

The point I am trying to make is that if you are running the Hobart generator to power the guys welding with a NG fueled engine is fine and quite doable. However the part of using batteries and inverters and what ever else to run the 480 VAC powered other stuff off of it remaining output capacity is.

As far as four guys using over 48 KW of auxiliary power when welding is simple. Just start a large air compressor of motor and see what its peak input surge power is. Then again maybe you don't have any large motor loads. I don't know being you have yet to explain what exactly the 480 VAC 100 amp single phase power is going to run.

To further complicate things have you calculated out what your operating cost to run this system will be as in preventative maintenance possible break downs and the like? Big engines running big generators charging big batteries running big inverters do not run forever for free with no maintenance!

So what exactly are you paying for NG per unit of energy? You have yet to revile that detail so I can not confirm any of your calculations or estimations on this either. From what I can finding line bulk rate NAG is around $3.47 a MMBTU which is a million BTU hours or roughly 293 KWH's of electricity.

Here is what I get from those numbers. 1 million BTU of energy from NG cost $3.47 whereas 1 million BTU of energy from electricity costs about $67 at your price of $.24 per KWH.

Assuming 35% engine efficiency and 85% generator efficiency that works out to 1 MMBTU of NG will generate at most ~87 KWH of electrical power or roughly $20.90 worth of electrical power.
Now going from there I checked around and a good used low running hours 100 KW 480 VAC three phase gen set already built for NG or LPG operation is going for around $10,000 or less. But any industrial power inverter capable of 48 KW or more at 480 VAC three phase is pushing $40,000+ and all of them at that power level are running 96 volt to 280 volt Dc battery bank systems not 48 volt.

The way I see it is that going NG theoretically after conversion to electrical power may cut your electrical power costs down to around 5 cents a KWh factoring bare minimal gen set maintenance costs however to offset the cost of your design with the Hobart welder generator, battery bank, related components to hook all that up and make it work, plus near impossible and likely outrageously priced inverter I suspect your base investment would be $50K + or there which even if you are saving some 19 cents a KWh would take your system running approximately 50,000 / .15 = 333,333 running KWh hours (~4 - 5 working mans years) at 38 KWh per hour to pay for it self in savings on a 19 cent a kwh savings offset.

Thats the math I have issues with.

What did you come up with that made you think this was a cost justified way to go?

Now that I have had more time to research this and think about it given the present info implied I have came to the conclusion that since the NG source must be utility supplied its coming from a fixed point which means this whole concept is for a static setting such as a shop and not any reasonable form of portable welding or field service work.

From that its would make the most sense that all or at least most of the welding is done presently from electrically powered welding systems, not engine driven ones, most likely powered from a 277/480 volt three phase service. Given that estimation I would suspect that the main power source for the shop would be at minimal a 100 amp three phase service which puts its peak continuous working capacity at 80% of 3 x 100 x 480 = 144,000 which is 115 KW not 48 and sounds about right for what I would expect a small welding shop to be wired with.

Given the utility source of NG and the intentions of using the excess heat produced by the engine to heat the shop it does work out to initially be a cost effective way to run if a large 100 - 150 KW 277/480 VAC NG fueled gen set was used to power the whole shop. But the kicker here is realistic operating cost associated with gen set maintenance over the long run.

Given a 150 KW NG powered gen set costs around $15,000 - $20,000 and could be connected to the electrical systems plus heating systems for very little additional costs this concept could work cheaply for a while but........... The problem is run time life expectancy of any engine regardless of fuel source meaning that the gen set will not run indefinitely for nothing. Very few standard industrial engines will make it much past 20 - 30 thousand running hours before needing major rebuilds and all of them need regular oil changes and related maintenance. If continuously ran 30,000 hours works out to be about 3.4 years.

However that said assuming a 19 cent a KWh savings running an average 24 hour a day base load of 38 KW per hour a $20,000 gen set would pay for itself in around 20,000 / .19 = 105,263 KWh or roughly 2770 running hours or about 1/10 of its expected running life time and with near zero discombobulated set up or in conveniences to everyone else who works at the shop plus the shop itself gets free heat all winter!

I see this type of dedicated setup as being completely doable and cost justifiable in the long run and in fact many large businesses do run off of NG powered gen sets during peak load times during the days to avoid peak power usage charges from the utilities. By only using utility power during off peak times the customer qualifies for off peak power rates opposed to full rates and the NG fueled gen sets are automatically switched on and off line by the utility for peak load shedding without the customer ever needing to deal with it directly unless they want to run of the gen set on purpose during off peak load times.

The other option with a 150 KW capacity NG powered gen set is that by doing co gen and selling excess power back additional savings and possible profits could be had. Given a 100 KWh per hour sell back at even 5 cents per KWh that gen set could produce around .05 x 100 x 24 x 30 = $3600 in electrical resale per month on top of its cost saving figures. From that you get your $80,000 avoided electrical power consumption plus free heat for the shop and potently $3600 sell back profits every moth which could pay for much of the monthly NG bills alone!

That's what know about using NG fuel as a electrical power saver for commercial and industrial applications with larger power consumption issues. Its been done for decades and by 100's of thousands of large businesses and power consumers already. (But with simple solid well proven dedicated gen sets and off the shelf systems and designs.)

<The discombobulated part is the using the welder generator to charge a set of batteries to further drive a very big inverter to supply the 480 volts AC while still functioning as a welder is.>

Where did you get this information?..480 volts ac ?
I never said that. reread the layout.

I sourced an inverter. Its a 48 dc volts to 240 vac @100 amps for less than 5000.$ That is lots of amperage. More that four guys would ever use.

I told u lots. The price of the ng @ $5.00 per gj

Inverter~ $5000.00
2 x 24 volt Batteries @~ 450.00 =900.00
Total cash investment for the power and welding ~ $6000.00

<As far as four guys using over 48 KW of auxiliary power when welding is simple. Just start a large air compressor of motor and see what its peak input surge power is. Then again maybe you don't have any large motor loads. I don't know being you have yet to explain what exactly the 480 VAC 100 amp single phase power is going to run. >

I never said that. You did. You seem to be making things up to confuse yourself.
I've already explained this in my last post; (yet another way of saying this) : 4 welders would not even use half of the available 800amp capacity. I don't see any problem with a 22amp 5hp compressor starting up. ( an other way of saying this)
The Hobart puts out 38.4 kwh. Dc Per hr.!! IF half of that is welding, that leaves 19.2 kwh dc for auxiliary inverted power. Even with inverter losses it would be impossible to use up that power when the guys are welding. That's 50 amps for lights, radio and compressor. Add the battery back up...no problem! . I would really be surprised if the batteries would even get run down in the course of a 10 hr day.
My other welder is a Millar 302 with 10kwh of ac power. I can air arc all day long. the compressor is 240v , 3hp. Plugged to the welder. I have never run out of air nor ever had any issues.

A new engine for the hobart and related maintenance amortized over it's lifetime = $ 1.25 per hr.

Like I said; 10 hr per day, 20 days per month. For contracts only. I do not, nor do I have intention to be working more than 3 or 4 mo of the year. Welding that is. The rest of the time the Selectronic inverter automatically starts the genset to charge the batteries. If need be. ?

< From that you get your $80,000 avoided electrical power. >

??? Where on earth did u get that figure? I've ready corrected u on that one.

Post 21

1000 amps translates to 100 amps of inverted ac power. No grid no exciter NO SYCRONIZER and that is very affordable. Ive already stated ...on ng power at 5.00 gj what's the problem?

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What am I supposed to think? 1000 amps on a 48 volt battery system turns into 100 amps of AC power, to me the math suggests 480 VAC.

Now for the second part 5 gigajoules converts over to 1,388,889 Watt hours or 1389 KWh's or 4,739,124 BTUh's. https://www.rapidtables.com/calc/electric/Joule_to_Watt_Calculator.htm

From that I am assuming that you are using 10% of that to get your 38 KWH's of electrical energy assuming a roughly 27% conversion efficiency.

Now for the part of 50 cents worth of power equating to $400 profit do you not pay your guys anything and do you have zero cost outlay for your welding consumables plus zero maintenance or accessory costs in your welding shop operations?

Around here a good certified person doing a welding job makes around $25 an hour plus from personal welding experience I easily burn up at least $25 an hour worth of consumables plus my personal home shops general overhead is probably anther $25 on top of that when I am doing fabrication work. For an honest welding shop a $400 welding job may turn over $100 profit after all expenses are factored in.


We seem to have a failure to communicate in common terms of technical and true costs.

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Going back to your first post here is the answer I can give you. A 48 volt lead acid based battery bank will need around 56 - 58 volts to fully charge properly and around 53 - 54 volts to float charge. After that your surge capacity is only limited by what your inverters designed surge ratings are.

As far as welding off of one output while charging batteries off the other with a expensive inverter hooked up personalty I would not try it.

What am I supposed to think? 1000 amps on a 48 volt battery system turns into 100 amps of AC power, to me the math suggests 480 VAC.

You do not know how to convert dc amps to inverter power. My electrician/ electronic tech. told me what I told you and mean 240 ac volts 100 amps. I know the math suggest otherwise but he used a formula which I thought was well known in your gendra.


$ 5.00 PER GJ.

Re :Your next two paragraphs I've already corrected you on those assumptions. 400.00 profit.??? who said that? re read the post. FYI the welders are partners in this enterprise and after cost, split the income. (Any welder in my field normally make anywhere from 40.00 to 67.50 per hr.. By hand. )

<We seem to have a failure to communicate in common terms of technical and true costs. >

Mainly because u are making assumptions instead of reading the post.
"38.4 kwh = 400.00$ " means exactly that

<Going back to your first post here is the answer I can give you. A 48 volt lead acid based battery bank will need around 56 - 58 volts to fully charge properly and around 53 - 54 volts to float charge. After that your surge capacity is only limited by what your inverters designed surge ratings are. >

Yes thank you of coarse. That's already been reviewed and taken care of. But I will investigate the surge ratings for the inverter.

<As far as welding off of one output while charging batteries off the other>

The batteries will be on the same line hooked up in parallel between the generator and the remotes ( rheostat )

<with a expensive inverter hooked up personalty I would not try it. >

Ok I think we covered that. If I remember correctly the electrician/ electronic tech. are implementing filters.
I personally do not know exactly how that works. But apparently does not pose a problem on the other installation that we are copying.

And like I said the final draft will past an engineer. I'm not going to lift a finger before I know my machines will not be wrecked.

Thanks and happy new year.
H.

So you are making $400 profit after all other expenses off of $9.21 in electricity and thinking that's not enough?

As far as your wanting to run the shop and your house off of NG power that's fine but I still don't see the logic behind running a welding generator through a power filtering system then to a set of batteries then to a inverter to get your AC power.

Why not just run a dedicated second generator head on the system that puts out a normal 120/240 VAC power at what ever KW range you need and skip the batteries and inverter all together?

What I am finding online is any 48 volt to 120 VAC inverter that costs less than a good name brand 12 KW or larger 120/240 VAC commercial generator head (under $1500) is a cheapo Chinese unit with a modified sine wave output and at best around 6000 - 7000 watts output capacity.

BTW how old is your Hobart 800 pipeliner welder? I cant seem to find any references to anything like that is not at least 40 - 50+ years old? Just curious being I have welder and plasma cutter related service archives that cover around 10,000 different machines from at least 20 major world wide manufactures some going back over 80 years!.

So you are making $400 profit after all other expenses off of $9.21 in electricity and thinking that's not enough?

Again, who said anything about profit???
Read carefully
38.4 kwh = 400.00 $

I must respectfully request we terminate this conversation. I've explained this in several way and all I'm doing is repeating myself. I've explained this to several professionals in as little as 3 sentences and they all get it. You given me a couple of pointers and I thank you
Sincerely
Henri
Ps I feel obliged to leave you with these words
Human intelligence amongst of several things, these few are paramount..
- a repertoire of concepts
- a process of metaphorical abstraction
- the educational process that resolves problems, resolves the doctrine of men and traditions of men.
-never wasting your time trying to explain who you are to people who are committed to misunderstanding you.
- social responsibility, being a reflection of the entire heritage that came before and a reflection to all that follow

Sent from my iPhone

Again, who said anything about profit???
Read carefully
38.4 kwh = 400.00 $

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Well you got me there I have no clue how that adds up. So far 38.4 KWh equals 50 cents NG or $9.21 in utility electricity so yea I have no clue how you are getting $400 for it now turning NG into electricity thats only worth $9.21 utility rate but you say its not welding services profit or avoided cost being the numbers don't come any where close to adding up.

As far as engineers go if you are paying them well or they think you will be they will agree with anything after three sentences!

Anyone else following this thread got any clues how 38.4 KWh = $400 in all of this?

tcmtech said:

Well you got me there I have no clue how that adds up. So far 38.4 KWh equals 50 cents NG or $9.21 in utility electricity so yea I have no clue how you are getting $400 for it now turning NG into electricity thats only worth $9.21 utility rate but you say its not welding services profit or avoided cost being the numbers don't come any where close to adding up.

As far as engineers go if you are paying them well or they think you will be they will agree with anything after three sentences!

Anyone else following this thread got any clues how 38.4 KWh = $400 in all of this?

Click to expand...

I am somewhat loathe to interject anything into this thread, especially since the OP has opted out of further discussion, but...

Original numbers given by the OP in post #13:

Henrine7 said:

@tcmtech
38.4 kwh is worth about ~ $400.00 in welding income <My emphasis>
38.4 kwh is worth about $9.00 sold back to the grid.
Both cost about .50 to produce using natural gas.
These are just very rough figuring just to give you an outline of the cash flow and R.O. I .

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Don't have a clue to the veracity of the numbers given, but with regard to tcmtech's last post, I thiink the $400.00 figure is income genrated from the use of 38.4 kwh, income being what the customer pays for the finished product(s)/service(s) provided as opposed to the final profit (probably something on the order of 10% to 30% of the income).

That's my take on it, anyway...

Don't have a clue to the veracity of the numbers given, but with regard to tcmtech's last post, I thiink the $400.00 figure is income genrated from the use of 38.4 kwh, income being what the customer pays for the finished product(s)/service(s) provided as opposed to the final profit (probably something on the order of 10% to 30% of the income).

That's my take on it, anyway...

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That's just it. All the numbers given and the reasoning behind the designs have been very vague at best leaving me to speculate at a lot of it and fill in the blanks from there then get shot down for those assumptions.

The thing is when a person or company does work for a customer you don't factor one single item of the whole job outlay as being the sole point of the overall job cost s or profit.
Its like me saying that I built a custom boiler system that took $4000 in materials and $12 in electricity to build and then when I sold it for $7000 the electricity was responsible for the $4000 cost of the project or the $3000 profit at the end.
Nope. It was just one of many consumables and general expenditures that as measured by its market value was worth $12. No more no less.