Generator Load Bank questions

[Bowtiepower00]

IMO you’re overthinking this. Take the thing out occasionally during desert season and power your camp with it like you mentioned earlier. Or plug your RV into it at home. Turn on the A/Cs for more load.

 

[Blackmagic94]

load bank for 1-2 hours every 1000 hours, it’ll be fine. That’s a 3 phase gen, so you’ll need a 3 phase load bank, ideally.

I have this one-

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The load bank mainly enables the gen exhaust to hit target temps, or hot enough to burn off all the crude in there.

When we got that one a year ago small load banks were hard to get your hands on, ended up drawing it out of government stock.

I was just talking with Cummins trying to find out the target exhaust temp for a small diesel gen, they couldn’t tell me, but for their big gens it’s like 900 degrees I believe.

It’s wired up in single phase. You can run either way so he doesn’t need a 3 phase

 

[hallett21]

IMO you’re overthinking this. Take the thing out occasionally during desert season and power your camp with it like you mentioned earlier. Or plug your RV into it at home. Turn on the A/Cs for more load.

Even at 24/7 he’d only have to do that every 6 weeks if 1,000 hours is the number.

 

[Dalton]

It’s wired up in single phase. You can run either way so he doesn’t need a 3 phase

When it’s wired up for single phase it’s just using 2 of the 3 phases. A 3 phase gen can do single phase, but a single phase gen can’t do 3 phase.

Powering single phase items off a 3 phase gen technically is creating an uneven load, and it’s recommended to use L1 and L3 when you need to power single phase items.

Now, in deployed environments these gens will run for years powering something like 2 radios that pull 500 watts and never get a load bank. So even a single phase load bank would probably be better than no load bank.

Also, the rating of these things degrades the further you go over 100 degree ambient, the recommended minimum load is something like 30%, so in the summer it may be hitting that regularly.

It’s easy to go down a rabbit hole with these gens.

 

[Taboma]

When it’s wired up for single phase it’s just using 2 of the 3 phases. A 3 phase gen can do single phase, but a single phase gen can’t do 3 phase.

Powering single phase items off a 3 phase gen technically is creating an uneven load, and it’s recommended to use L1 and L3 when you need to power single phase items.

Now, in deployed environments these gens will run for years powering something like 2 radios that pull 500 watts and never get a load bank. So even a single phase load bank would probably be better than no load bank.

Also, the rating of these things degrades the further you go over 100 degree ambient, the recommended minimum load is something like 30%, so in the summer it may be hitting that regularly.

It’s easy to go down a rabbit hole with these gens.

If he were only using 2 of 3 available

When it’s wired up for single phase it’s just using 2 of the 3 phases. A 3 phase gen can do single phase, but a single phase gen can’t do 3 phase.

Powering single phase items off a 3 phase gen technically is creating an uneven load, and it’s recommended to use L1 and L3 when you need to power single phase items.

Now, in deployed environments these gens will run for years powering something like 2 radios that pull 500 watts and never get a load bank. So even a single phase load bank would probably be better than no load bank.

Also, the rating of these things degrades the further you go over 100 degree ambient, the recommended minimum load is something like 30%, so in the summer it may be hitting that regularly.

It’s easy to go down a rabbit hole with these gens.

Here, this might help you understand how Dave has chosen to configure this generator to best serve his needs --- which are not 3 phase and he's not creating an unbalanced WYE phase.

 

[Mikemo_SDS]

load bank for 1-2 hours every 1000 hours, it’ll be fine. That’s a 3 phase gen, so you’ll need a 3 phase load bank, ideally.

I have this one-

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static-gcs.edit.site

The load bank mainly enables the gen exhaust to hit target temps, or hot enough to burn off all the crude in there.

When we got that one a year ago small load banks were hard to get your hands on, ended up drawing it out of government stock.

I was just talking with Cummins trying to find out the target exhaust temp for a small diesel gen, they couldn’t tell me, but for their big gens it’s like 900 degrees I believe.

I have multiple customers that run into wet stacking after 200 hours or less of unloaded runtime on stand by gensets that are 10-250kw. We provide a service that load tests your standby genset at 25, 50 and 85% load for 2 hours annually.

 

[Dalton]

If he were only using 2 of 3 available

Here, this might help you understand how Dave has chosen to configure this generator to best serve his needs --- which are not 3 phase and he's not creating an unbalanced WYE phase.

View attachment 1433389 View attachment 1433390

I’ll have to get into the wiring diagram, but I imagine the 3rd phase in the alternator still exists

 

[Dalton]

I have multiple customers that run into wet stacking after 200 hours or less of unloaded runtime on stand by gensets that are 10-250kw. We provide a service that load tests your standby genset at 25, 50 and 85% load for 2 hours annually.

Dave may be doing more load banks than oil changes at this rate. I kid. lol

 

[Dalton]

If he were only using 2 of 3 available

Here, this might help you understand how Dave has chosen to configure this generator to best serve his needs --- which are not 3 phase and he's not creating an unbalanced WYE phase.

View attachment 1433389 View attachment 1433390

I’m reading about this and you may be correct, I’ve been messing with civilian generators for a while where if it was 3 phase you wanted a 3 phase load bank etc… but I need to get into the wire diagram to see what it really does in this mil gen when you turn that switch.

 

[RiverDave]

So this is what the control panel looks like (note the knob that controls the outputs) and the wiring

As well as the electronics cabinet that I’d like to fit the load bank in.

 

[RiverDave]

What is running load of the trucks AV setup?

You mentioned the LED panels. Plus the rack of audio gear / amps, plus 2 air conditioners.......I would think you have to be pulling somewhere between 4000-5000 watts when it's all in use? Thats almost 50% load of a 10KW generator. That's not enough to prevent Wet Stack?

The screen can be run on two normal plugs the electronics take nothing.. the air conditioners are crazy efficient nowadays too..

It’s a bizarre problem to have

 

[RiverDave]

When everything is running the % rated current gauge is hovering just above zero.. as an fyi.

When it was running it definitely smells like diesel fuel so I’m thinking this wet stacking is gonna be a problem at a lot less than 200 hrs let alone a 1,000.

RD

 

[Blackmagic94]

Install a fridge and ice maker to make drinks lol

 

[Your ad here]

Where is there a reported case that wet stacking cause a generator problem?

 

[Sharky]

Run a couple AC units. Offer a cooling station.

 

[Dalton]

When everything is running the % rated current gauge is hovering just above zero.. as an fyi.

When it was running it definitely smells like diesel fuel so I’m thinking this wet stacking is gonna be a problem at a lot less than 200 hrs let alone a 1,000.

RD

No fuel leaks from return fuel lines? Or leaks in general?

I think the oil changes are every 250 or 300 hours on that, you won’t need to shut it down before then just for a load bank. Get some run time on it and see how oily the exhaust actually gets.

 

[Dalton]

Where is there a reported case that wet stacking cause a generator problem?

Why does the term wet stacking exist lol

 

[Dalton]

If he were only using 2 of 3 available

Here, this might help you understand how Dave has chosen to configure this generator to best serve his needs --- which are not 3 phase and he's not creating an unbalanced WYE phase.

View attachment 1433389 View attachment 1433390

Thinking out loud, so the goal is pull MORE amperage, will he pull more amps using L1 and L3 with the gen set to 208 3ph or 240 1ph? Or the same?

Or a better way to put this, which configuration would put more load on the gen, because I believe in the 240 1ph configuration it’s rated for more amps than the 208 3ph configuration

 

[rrrr]

7500kw

It's some other number, 7500 kW is 7.5 megawatts. I know this isn't your area of knowledge. Is it 7.5 kW? 75 kW?

You could buy a couple of junk electric kitchen ovens on FB marketplace and hook 'em up. That'll produce a 5 kW load. But that's still not much if it's a 75 kW unit.

 

[hallett21]

It's some other number, 7500 kW is 7.5 megawatts. I know this isn't your area of knowledge. Is it 7.5 kW? 75 kW?

You could buy a couple of junk electric kitchen ovens on FB marketplace and hook 'em up. That'll produce a 5 kW load. But that's still not much if it's a 75 kW unit.

10kW generator

 

[rrrr]

10kW generator

Well then, FB marketplace for the win!

 

[Blackmagic94]

Where is there a reported case that wet stacking cause a generator problem?

lol it’s a real thing. I’ve experienced it in person

 

[RiverDave]

No fuel leaks from return fuel lines? Or leaks in general?

I think the oil changes are every 250 or 300 hours on that, you won’t need to shut it down before then just for a load bank. Get some run time on it and see how oily the exhaust actually gets.

Eric redid the fuel system in the generator. I have not put fuel in the new external tanks yet to check for leaks. That will be happening tomorrow as soon as the insurance gets bound. .

Putting five gallons in each tank and checking for leaks then filling everything up.

RD

 

[RiverDave]

So if I’m reading this right I may not need a load bank at all.. but rather just run it hard by plugging into my motorhome once a week for a couple hrs?

 

[yz450mm]

Just install a 240v plug in one of the cabinets, buy a cheap resistive load like this shop heater, and plug it in every once in a while to have the generator do some work.

Any electrician can wire up the heater with a plug instead of being hardwired, FYI.

 

[hallett21]

So if I’m reading this right I may not need a load bank at all.. but rather just run it hard by plugging into my motorhome once a week for a couple hrs?

Yep!

 

[RadMan]

Dude….

 

[Ladsm]

Install a manual transfer switch at the shop and run the shop off of it occasionaly. All a load bank is a giant heater. You just need to load it up occasionally. On commercial office buildings we used a load bank once a year.

 

[Bigbore500r]

So if I’m reading this right I may not need a load bank at all.. but rather just run it hard by plugging into my motorhome once a week for a couple hrs?

If its a 10kw Gen, thats 10,000 watts. If your video / AV setup pulls near 1000 watts, and your 2 ac units pull 2000 each (an AC unit that can run on 2000 watts is pretty efficient...) that would be 5000 watts, or 50% of your generators capacity. You need to add up the running load of what everything pulls that you are hooking to the generator that's being used simulateously, and see where that puts you. If its somewhere near that number, I can't see why you would need to do anything but run the generator powering that setup as it is. Why the gauge would read 0% load - I have no idea, possibly because its not measuring the leg(s) your hooking into ?

 

[hallett21]

Install a manual transfer switch at the shop and run the shop off of it occasionaly. All a load bank is a giant heater. You just need to load it up occasionally. On commercial office buildings we used a load bank once a year.

Also put one in at your house @River Dave

Perfect way to make sure you’re always covered.

 

[Bajastu]

When everything is running the % rated current gauge is hovering just above zero.. as an fyi.

When it was running it definitely smells like diesel fuel so I’m thinking this wet stacking is gonna be a problem at a lot less than 200 hrs let alone a 1,000.

RD

Correct, if you are wet stacking, the cylinder washdown is always happening. Load banking it occasionally does not solve your long-term problem of continuous engine wear.

Either your gage is off, or its not measuring the leg load. You need to find a way to load the generator while in use. Proper load or downsizing is ultimately the solution. At CAT we would load bank our gensets but not continuously. Constant high-level load at breakpoint peak is not good for the generator neither is continuously running a load bank going to last long.

 

[Taboma]

Correct, if you are wet stacking, the cylinder washdown is always happening. Load banking it occasionally does not solve your long-term problem of continuous engine wear.

Either your gage is off, or its not measuring the leg load. You need to find a way to load the generator while in use. Proper load or downsizing is ultimately the solution. At CAT we would load bank our gensets but not continuously. Constant high-level load at breakpoint peak is not good for the generator neither is continuously running a load bank going to last long.

How does Cat build Marine engines that spend the vast majority of their life cycle at far less than 70% or higher throttle ?
Most sportfishers or even larger yachts don't perform a day fishing or long range transits at more than 30% throttle, often far less. So in terms of % of hours, 70+% throttle time was rather insignificant.
Or do they just suffer the consequences of a diminished life-cycle and higher maintenance ?

 

[hallett21]

How does Cat build Marine engines that spend the vast majority of their life cycle at far less than 70% or higher throttle ?
Most sportfishers or even larger yachts don't perform a day fishing or long range transits at more than 30% throttle, often far less. So in terms of % of hours, 70+% throttle time was rather insignificant.
Or do they just suffer the consequences of a diminished life-cycle and higher maintenance ?

Magic!

 

[Maw]

How does Cat build Marine engines that spend the vast majority of their life cycle at far less than 70% or higher throttle ?
Most sportfishers or even larger yachts don't perform a day fishing or long range transits at more than 30% throttle, often far less. So in terms of % of hours, 70+% throttle time was rather insignificant.
Or do they just suffer the consequences of a diminished life-cycle and higher maintenance ?

I don't know about modern marine engines, but on my older two-stroke Detroits I make a point to run fairly hard after a weekend spent trolling for tuna. On the way back in I get on top and run the engines for at least 30 minutes with the EGT pyrometers up around 900F.

The same for the generator, 15kVA/12kW rated Onan that only gets to 2kW max on a weekend out at San Clemente Is. The boat was originally a Fort Lauderdale charter boat with five chillers, all got stripped and pitched when we bought it, no need in SoCal waters plus I could use the space in the engine compartment. We don't have enough load aboard to make it sweat so I lug a load bank from the shop down to the dock a few times a year and make it work for an hour or two.

 

[Taboma]

I don't know about modern marine engines, but on my older two-stroke Detroits I make a point to run fairly hard after a weekend spent trolling for tuna. On the way back in I get on top and run the engines for at least 30 minutes with the EGT pyrometers up around 900F.

The same for the generator, 15kVA/12kW rated Onan that only gets to 2kW max on a weekend out at San Clemente Is. The boat was originally a Fort Lauderdale charter boat with five chillers, all got stripped and pitched when we bought it, no need in SoCal waters plus I could use the space in the engine compartment. We don't have enough load aboard to make it sweat so I lug a load bank from the shop down to the dock a few times a year and make it work for an hour or two.

You're making my exact point, this is how it's commonly done in the marine environment.
When fishing, as you do, we'd run them up returning, or maybe chasing birds mid-day to blow em out (As we all say over brews ).
Same with gen sets, we have them sized for loads we only use on occasion, so again, the majority of their life cycles are not spent at optimum RPM.

When I was on LCM's in the Army, the Quad 6-71's were exercised in a similar manner when rivers and territory, some requiring slow, others push the sticks baby.

To answer Dave's question of how often he needs to load it up to optimal RPM, depends on a number of variables which I believe will require a learning process in order to see how the engine responds and make adjustments accordingly.

In this regard a transfer switch at home or using it to power his RV to occasionally load it as you use your temporary load bank, or maybe he could figure out how to install two 240V 25,000 BTU AC units and provide a cool zone at the shows giving free blow jobs to those standing there watching his screen.

 

[Cray Paper]

I am just a dumb carpenter but have experience with the exact same issue you are experiencing but at a scale most people cannot fathom. Accurately predicting intended loads seems the most difficult thing for owners to determine.

You not being an engineer or experienced in building something like you have happens way more than you think. A certain software company in Redmond WA spent more than 500 Million on a geothermal cooling system and totally miss calculated the loads that system was designed to cool. That huge investment in a system costs them several times more to cool their buildings then the system it replaced. They have to heat the water that is coming out of the thousands of 600' geo wells before it goes to the buildings, BOD was taking much hotter hydronic water from the buildings and cooling it, but the heat load from the campus was far less than anticipated.

Log story short, figure out your electrical loads at your intended usage and buy the right genset to power them. Adding a load bank to get the genset in to it's efficient operating range is just not very efficient or smart. You will be turning diesel in to heat, that is exactly what load bank testers are, heaters.

 

[Dalton]

How does Cat build Marine engines that spend the vast majority of their life cycle at far less than 70% or higher throttle ?
Most sportfishers or even larger yachts don't perform a day fishing or long range transits at more than 30% throttle, often far less. So in terms of % of hours, 70+% throttle time was rather insignificant.
Or do they just suffer the consequences of a diminished life-cycle and higher maintenance ?

It’s not really about throttle position, it’s about load, just because your throttles are at 70 or 100% doesn’t mean the engine has the proper load. Also- diesel gens live their whole life at 1800 RPM, 60 hz models anyways.

 

[Eliminator21vdrive]

^^THIS^^

 

[Taboma]

It’s not really about throttle position, it’s about load, just because your throttles are at 70 or 100% doesn’t mean the engine has the proper load. Also- diesel gens live their whole life at 1800 RPM, 60 hz models anyways.

Agreed
But come on
Let's not argue that throttle position, whether controlled by the hand, foot, governor, or ECU, isn't relative to achieving adequate engine RPM to manage various loads under varying conditions ?

Allow me to assure you, I wasn't referring to something like this

The vast majority of 3/4 ton to 1.5 ton pickups, capable of towing 12-25K lb trailers or more, spend 75% of their life-cycle, if not more, running empty and towing nothing and I can easily think of entire marinas filled with various diesel powered recreational pleasure boats that only rarely get properly exercised and various rental equipment that's abused daily in that regard.
Somehow, perhaps not ideally, but they do survive. Ideally we should have run our Army LCM-8's with a M-60 Tank in the hold, or carrying 80,000 lbs of cargo, but we didn't, we often ran them empty to get back to port.

But relative to this thread, that's all irrelevant, the only thing that is, is what does Dave's MEP-803A require and how frequently and what's his most reasonable course of action to achieve it. Perhaps a MEP-802A would have been a better choice, but that ship has probably sailed.

So, run it and find out, unless he's already done so and hence this thread.

Regardless, he's made it clear, he's hoping to use the truck in varying capacities, lightly loaded, but also capable of powering additional loads as the occasion demands. Ideally he'd have a variable load bank capable of being adjusted to optimum engine loading, but that's not going to happen.
Hopefully he can find a reasonable priced 4-6 KW 240V single phase load bank --- or go buy two Home Depot 240V 25,000 BTU AC's and blow cold air out one side and hot out the other.

 

[lbhsbz]

Find a couple guys with food trucks in town and arrange to park together...run the food trucks off the sign truck. Bonus is you'll probably get free lunch everyday

 

[yz450mm]

Find a couple guys with food trucks in town and arrange to park together...run the food trucks off the sign truck. Bonus is you'll probably get free lunch everyday

At the RDP Mobile Cafe', we bring the China Buffet experience to you!

 

[RiverDave]

So I ran this last night at my house for like eight hours.. while cleaning out the exhaust once in awhile is great in terms of functionality this thing is throwing diesel particulates in the air.. as in it’s a stinky diesel.. lol.

It’s out in my driveway and when there is no wind after an hour you don’t want to be within fifty feet from this thing.

 

[oldman]

A Fluke clamp amp on the load lugs will tell you right away.
Fire it up 100% and clamp your leads to see what your load is and help out with the gauge.

I know it's probably already been said though.

 

[oldman]

So I ran this last night at my house for like eight hours.. while cleaning out the exhaust once in awhile is great in terms of functionality this thing is throwing diesel particulates in the air.. as in it’s a stinky diesel.. lol.

It’s out in my driveway and when there is no wind after an hour you don’t want to be within fifty feet from this thing.

That sounds like something other than a loading issue, how much fuel did it burn?

 

[hallett21]

So I ran this last night at my house for like eight hours.. while cleaning out the exhaust once in awhile is great in terms of functionality this thing is throwing diesel particulates in the air.. as in it’s a stinky diesel.. lol.

It’s out in my driveway and when there is no wind after an hour you don’t want to be within fifty feet from this thing.

Maybe try it tied into the RV now.

 

[RiverDave]

A common theme in this thread is “why the f did you buy a generator that big?”

The answer is I wanted to power my motorhome and race trailer while we were camping..

I had no idea they couldn’t just idle with small loads. I just thought it was like my motorhome generator that can idle or run everything and back etc..

I’d really like to keep this generator because it’s already painted and installed l.. to do it over again I’d get an Onan out of a motorhome..

 

[RiverDave]

That sounds like something other than a loading issue, how much fuel did it burn?

That I don’t know.. I’ll know when I fill the tank up today

 

[RiverDave]

Maybe try it tied into the RV now.

The 50 amp out will be installed next week sometime

 

[RiverDave]

Find a couple guys with food trucks in town and arrange to park together...run the food trucks off the sign truck. Bonus is you'll probably get free lunch everyday

lol not a bad idea!

 

[c_land]

A common theme in this thread is “why the f did you buy a generator that big?”

The answer is I wanted to power my motorhome and race trailer while we were camping..

I had no idea they couldn’t just idle with small loads. I just thought it was like my motorhome generator that can idle or run everything and back etc..

I’d really like to keep this generator because it’s already painted and installed l.. to do it over again I’d get an Onan out of a motorhome..

Can you add a motorhome generator to one of the cabinets at this point? Seems like a drop in the bucket compared to what you have into this project.