Generator Load Bank questions

[Eliminator21vdrive]

Solar? Batteries and mini gen.

 

[SoCalDave]

I wish RD would just tell us the size of the generator and the load he's trying to support. That'd be a good starting point.

 

[Taboma]

I wish RD would just tell us the size of the generator and the load he's trying to support. That'd be a good starting point.

Ahhhh, well, it appears to this reader as though the "Starting point" ship sailed last summer along with the calcs for sizing a proper generator.
I'm going to guess the generator is 10KW and his running load is approx. 2.7KW max.
Seems odd to me that even a diesel generator can't withstand running at almost 30% load, as I'm sure there's job site gens performing duty this daily.
I thought the idea of powering the system off an invertor sourced by either batteries or the gen was a great idea, but is going to require a lot more coin than a load bank. The ROI, depending on actual usage should pencil out over wasting dollars producing heat.

 

[hallett21]

I wish RD would just tell us the size of the generator and the load he's trying to support. That'd be a good starting point.

I’m driving but it’s in the build thread

 

[DaveH]

He is using .4-.5 gph. Not really agreeing with the uneconomical way lol

sure it is. running up the hours on a generator that is more expensive to maintain and repair.

 

[RiverDave]

Tell me the kW rating and I can offer some suggestions for a load to stress the genset adequately.

@RiverDave

7500kw

 

[RiverDave]

Ahhhh, well, it appears to this reader as though the "Starting point" ship sailed last summer along with the calcs for sizing a proper generator.
I'm going to guess the generator is 10KW and his running load is approx. 2.7KW max.
Seems odd to me that even a diesel generator can't withstand running at almost 30% load, as I'm sure there's job site gens performing duty this daily.
I thought the idea of powering the system off an invertor sourced by either batteries or the gen was a great idea, but is going to require a lot more coin than a load bank. The ROI, depending on actual usage should pencil out over wasting dollars producing heat.

I’m not sure the wattage are pulling right now but I know with everything including to AC units it’s pulling 13 amps. There is a load gauge on the generator and it’s effectively at zero when everything is running.

 

[hallett21]

I’m not sure the wattage are pulling right now but I know with everything including to AC units it’s pulling 13 amps. There is a load gauge on the generator and it’s effectively at zero when everything is running.

3120 watts +/-

 

[RiverDave]

well then seems like a small genset to support the realistic load of the truck, wired to a x-fer switch, then run the big daddy when needed. very uneconomical the way its setup. like using a jackhammer to crack an egg.

We went with a big water cooled diesel because of the extreme heat we have in the summer. A harbor freight predator isn’t gonna last when it’s 120+ degrees out..

I wanted something that would be bullet proof regardless of weather.. I knew it was going to be overkill but I “assumed” it would be like my motorhome genset where it would be ok if nothing is on or if everything is on. That is not the case.. these big military generators you get a load on them and adjust the generator controls to the load.. (didn’t know that either at the time)

That all said I am perfectly ok with wasting energy. The generator is crazy efficient. At 100% load it burns a half a gallon an hour. We have 85 gallons of fuel on the truck total.

 

[Taboma]

7500kw

Then why is Blackmagic stating the gen needs to run at 7500-8000KW to prevent wet stacking ? He seems to be treating it as a 10KW unit.

2.7KW would be 36% of 7500 and would allow you to offer temp power to others, or your own RV if being used at an event.
This seems as if it should be a reasonable design spec so long as you occasionally run it up with some additional load.

 

[RiverDave]

3120 watts +/-

So we are using 3 of 7500 kilowatts?

 

[hallett21]

We went with a big water cooled diesel because of the extreme heat we have in the summer. A harbor freight predator isn’t gonna last when it’s 120+ degrees out..

I wanted something that would be bullet proof regardless of weather.. I knew it was going to be overkill but I “assumed” it would be like my motorhome genset where it would be ok if nothing is on or if everything is on. That is not the case.. these big military generators you get a load on them and adjust the generator controls to the load.. (didn’t know that either at the time)

That all said I am perfectly ok with wasting energy. The generator is crazy efficient. At 100% load it burns a half a gallon an hour. We have 85 gallons of fuel on the truck total.

I really think you could pull off the EV charging somehow.

Pad lock with a lock box? QR code you scan to make a payment to get the combo. Apparently everyone says there’s no charging out there.

Great advertising, make a buck or two and lead the generator Rev up a few times a month.

 

[RiverDave]

Then why is Blackmagic stating the gen needs to run at 7500-8000KW to prevent wet stacking ? He seems to be treating it as a 10KW unit.

2.7KW would be 36% of 7500 and would allow you to offer temp power to others, or your own RV if being used at an event.
This seems as if it should be a reasonable design spec so long as you occasionally run it up with some additional load.

Well I thought it was 7500? It might actually be a 10? I just shot him a text to verify. I honestly did not know that these things had to be loaded down when I bought it. I just figured the more power the better.

 

[RiverDave]

He responded it’s a 10kw..

 

[hallett21]

So we are using 3 of 7500 kilowatts?

3 of 7.5 if it’s a 7.5kw unit.

3000 watts is 3KW

 

[RiverDave]

3 of 7.5 if it’s a 7.5kw unit.

3000 watts is 3KW

Well
Apparently it’s 10,000 watts.

 

[RiverDave]

The issue with charging batteries is that once the batteries are charged there is no load

 

[Taboma]

He responded it’s a 10kw..

Well looking at your problem in a more positive light, with a disconnect switch on the dummy load, when you use this at an event, you'll have power to rent to other venues.

 

[hallett21]

The issue with charging batteries is that once the batteries are charged there is no load

Is an hour or two of “full load” not enough to stop the wet stacking?

I guess I don’t know how much idling is too much?

 

[RiverDave]

Well looking at your problem in a more positive light, with a disconnect switch on the dummy load, when you use this at an event, you'll have power to rent to other venues.

That was kinda the idea when we were building it. Power the vending trailer etc

 

[Taboma]

Is an hour or two of “full load” not enough to stop the wet stacking?

I guess I don’t know how much idling is too much?

Pretty much what they desired on the diesel boats I was on that either trolled or worked at reduced load the majority of the time. In other words, kick it in the ass on the way home or go chase a mid-day boil, blow-da-bitch out.

 

[Bigbore500r]

well then seems like a small genset to support the realistic load of the truck, wired to a x-fer switch, then run the big daddy when needed. very uneconomical the way its setup. like using a jackhammer to crack an egg.

Exactly.

 

[Bigbore500r]

I wish RD would just tell us the size of the generator and the load he's trying to support. That'd be a good starting point.

Generator - BIG
Load - YES

 

[RiverDave]

Exactly.

Not exactly.. they won’t survive the summer

 

[hallett21]

Not exactly.. they won’t survive the summer

Not to mention talk about making that rig look like cheap POS lol

 

[lbhsbz]

So we are using 3 of 7500 kilowatts?

13A @ 120V is 1560 watts

 

[Taboma]

13A @ 120V is 1560 watts

how's about if it's more in the 220-240v range ?

 

[McKay]

13A @ 120V is 1560 watts

I'm sure a 10K military generator is single phase at least. The few I have been around even have a 3 phase option. Guessing that's where the the 3120 watts come from.

 

[RiverDave]

how's about if it's more in the 220-240v range ?

I know nothing about electricity.. but I believe it’s single phase 220.

You can set it to whatever ya want though.. single phase three phase etc

 

[hallett21]

I know nothing about electricity.. but I believe it’s single phase 220

It is. Your load calc is correct.

 

[DaveH]

Not exactly.. they won’t survive the summer

dave we ran the piss out of cheap generac generators suppling power to cell towers here in vegas.....24x7 for months on end........it wasnt the heat that did them in here in the summer.

 

[Waterjunky]

Got to say Dave, I know lots of people running the hell out of the predator generators in stupid heat all summer long with less than idea airflow. They have no real issues. I think your overcomplicating this.

 

[Taboma]

Dave, if your gen is a Fermont MEP-803A, this link has several manuals available for download, one being for operation and maintenance.

https://media.greenmountaingenerators.com/wp-content/uploads/2012/09/02032607/MEP-803A-MEP-813A-Operators-Manual-TM-9-6115-642-10.pdf

 

[RiverDave]

dave we ran the piss out of cheap generac generators suppling power to cell towers here in vegas.....24x7 for months on end........it wasnt the heat that did them in here in the summer.

What did them in?

 

[RiverDave]

Got to say Dave, I know lots of people running the hell out of the predator generators in stupid heat all summer long with less than idea airflow. They have no real issues. I think your overcomplicating this.

To go back to a gas generator would be incredibly difficult at this point so we gotta make what we got work.

 

[DaveH]

What did them in?

abuse.

thats 720 hours a month. at 60mph......thats 43,000 miles in one month. needless to say they werent getting oil changes weekly.

 

[McKay]

I would still question if you will even have a wet stacking issue but if you believe you will I would look for a 4KW Rack Mounted load bank like used in data centers to test for cooling.

 

[RiverDave]

I would still question if you will even have a wet stacking issue but if you believe you will I would look for a 4KW Rack Mounted load bank like used in data centers to test for cooling.

Got a link?

The smaller the size the better

 

[McKay]

Here's a 10KW with channels so you could vary the load. Not sure what your sign truck looks like or if you could fit it.

Avtron SLS-10 / ASCO 2300 Load Bank, 10 KW rating for Generators and Data Center | eBay

Used Avtron SLS-10 load bank. I used these as generator load banks, but they will mount in a server rack to test HVAC load of a data center.

www.ebay.com

 

[McKay]

Here's a 4K.

4kW TDI Power SDL-1072 Rack Mountable Load Bank for Data Centers | eBay

4kW Data Center Load Bank. Rack Mountable Load Bank for Data Centers. • The modular 4 kWs are 19” rack mountable for direct substitution of a computer, data switch, modem bank or server. • Load banks can be assembled for 1–24 kW rack load simulation for front to back, hot aisle–cold aisle or...

www.ebay.com

 

[RiverDave]

Here's a 10KW with channels so you could vary the load. Not sure what your sign truck looks like or if you could fit it.

Avtron SLS-10 / ASCO 2300 Load Bank, 10 KW rating for Generators and Data Center | eBay

Used Avtron SLS-10 load bank. I used these as generator load banks, but they will mount in a server rack to test HVAC load of a data center.

www.ebay.com

If I could find one a little smaller I could fit it in the cabinet.. that might actually fit as well I need to look up the dimensions

 

[McKay]

See the 4K unit I posted next if smaller is needed. These are used to simulate cooling loads of servers before fucking up a spendy server.

 

[Mikemo_SDS]

If I could find one a little smaller I could fit it in the cabinet.. that might actually fit as well I need to look up the dimensions

Load banks are essentially just a blow dryer. They use energy by heating an element and blowing air across it to keep from overheating. Make sure it is ventilated wherever you mount it.

 

[lbhsbz]

Got room on the truck for an ice maker and refrigeration unit?

 

[Dalton]

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-

https://static-gcs.edit.site/users-files/b4b6b6b67fd0191802d72bbb861fd255/l-63-flyer-2.pdf?dl=1

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.

 

[Taboma]

If I could find one a little smaller I could fit it in the cabinet.. that might actually fit as well I need to look up the dimensions

That 4KW example is 208V, not 240 and I doubt this generator has the capability to output both 208 and 240 simultaneously as one is Wye and the other single phase, not 3 phase Delta.

 

[Taboma]

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-

https://static-gcs.edit.site/users-files/b4b6b6b67fd0191802d72bbb861fd255/l-63-flyer-2.pdf?dl=1

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.

Can he output both 3ph and single phase 120/240 simultaneously with this mil-spec gennies ?
Why would the electrical side load nature matter, so long as the engine was seeing the proper 75-80% load ?

 

[RiverDave]

See the 4K unit I posted next if smaller is needed. These are used to simulate cooling loads of servers before fucking up a spendy server.

These can be continuous use right?

 

[Dalton]

Can he output both 3ph and single phase 120/240 simultaneously with this mil-spec gennies ?
Why would the electrical side load nature matter, so long as the engine was seeing the proper 75-80% load ?

The main alt/gen is 3 phase, the stuff he’s powering is only single phase I’m sure, he’s probably using L1 and L3, which is fine, but for a full load I think you would want the phases loaded evenly- L1 L2 L3

 

[Bigbore500r]

Not exactly.. they won’t survive the summer

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?