MEP-802A electrical output hookup

[sl33k3r]

Good day!

My wife and I live off-grid on a 30 acre spread that has three out buildings. Until we have the means to build a single large building to house all our equipment, each building has it's own purpose (woodworking, garage, metalworking). Our house is photovoltaic with a large battery bank with 2kw inverter generator for backup and charging. For the purpose of this post, all electrical association is with the out buildings and field work. Each out building has it's own small photovoltaic and battery supply for lighting and other low current demand tools.

I have a MEP-802A that is to be truck mounted as is an air compressor, welder and a box of tools so all are mobile and can be used at any location on the farm.
I have no trouble with single phase power but three phases appears to have me guessing a bit and I don't like to guess with something that has the potential to kill me.

Please let me know if I am wrong. And feel free to guide me in the right direction.

Three phase equipment will not work on single phase without a converter.
Single phase will work on three phase but load balancing should be a concern.
I am most likely the only person to be using tools so balancing may not be an issue, but I want to be prepared in case I do have others there who may be using tools while I am working as well.
I want each building to have a single connection for electrical and air where each will be distributed to where it's needed.

This is where I need advice. I'll have a ground rod at each connection. Should the building's distribution box be grounded or should I connect ground rod to the generator on the truck?

Also, what is a good connector pair for such a connection of the building/discribution box to the generator?

 

[155mm]

The way I translate NEC, which means..... in my own opinion, which is only worth what you paid for it...... ground box, ground generator, but only bond neutral to ground at 1 point. Grounding points must be more that 6' apart.

Electricity is always looking to return to the source, so my choice would be bond the ground to neutral at the generator.

Second question, I like the 50amp RV plugs, easy access to parts

 

[Coug]

you have the 3 phase/single phase accurate, unless you have some type of 3 phase equipment you plan to run with it, you'll likely put it into 120/240 mode and never touch it again. The only time I ever do mine in 3 phase is to run a 3 ton ECU with some of the heater elements disabled ( it's 9kw with all 9 elements, I disabled 3 to bring it to 6kw) as a load bank to burn off any wet stacking.

The distribution box should always be grounded, and the generator should be grounded by itself if possible, so as 155mm just stated, make sure only one spot has the ground/neutral bond. It should normally be inside the distribution box, but because everything is off grid and distributed like this, and you are going to be using the generator when it's not hooked to a box, you might be better off just leaving the generator neutral/ground bond attached and disconnect inside the boxes. I'm not up to 100% on NEC for your particular situation though, so same caveat, use my opinion at your own risk.


if the 5kw is the largest gen you ever expect to hook up, they make a 30 amp twist lock inlet box specifically for generators. If you're never using anything larger than the MEP-802A at 5-6kw, then 30 amp is all you need. The 30 amp gear is less expensive (not by a whole lot, but still a bit) easier to find in stores (Home Depot usually has 30 amp inlet boxes in stock, 50 amp are usually special order) the cables are smaller gauge, wiring is lighter, so the cost savings add up, especially if you are doing multiple buildings.

Reliance Controls 30 Amp Power Inlet Box PB30 - The Home Depot

The Reliance Controls 30 Amp Power Inlet Box is designed for outdoor use and can be hardwired directly to a manual transfer switch or transfer panel, eliminating the need for cords running through windows

www.homedepot.com

 

[sl33k3r]

Thank you for your input.

Looks like I need to drive 2 ground rods more than 6 feet apart at each building location. One for the distribution box and one for the generator/truck combination

I am going to have three phase equipment. Planers, saws, mills, lathes and such. The equipment I'm intending on using is industrial or commercial machinery. I can buy this type of equipment at auction for a fraction of new lighter-duty single phase residential/consumer level equipment. Or if the price is equal for the single vs three phase, the power/quality/durability is much more desirable for the used commercial three phase machines. They will be a part of my source of income after our building projects on the farm have completed. And I am fortunate that my wife does not question that good tools are worth their weight in gold as she also uses them with pride.

I had looked at the prices for connectors and was shocked to see the difference between 50A and the 30A connectors. Supposing 6 kW (surge) / 208 V = 28.8 A maximum for a single hookup. But suppose 120 V. 6kW (surge) / 120 V = 41.7 A maximum current. That will not happen since the correct breaker (30 A master or a 20 A line breaker) will trip in the distribution box in the building so as not to overload the weakest link.

Also, considering a good maintenance schedule, what is the longevity of the MEP-802A. I was fortunate in my acquisition of my machine. I purchased one with over 1,200 hours and thought I got it at a good price. But when I showed up to pick mine up, it was nowhere to be found. I was instead brought a machine with 2 1/2 hours on a fresh rebuild...complete with the test paperwork. I was pleasantly pleased. I would like to have an idea of how long I can enjoy this machine before I should be looking for its backup or a rebuild.

 

[smokem joe]

Be aware that the motor startup on the 3 phase equipment may draw more than the gen set can put out. Electric motors have a huge draw when trying to start

 

[Coug]

208 3 phase uses a different connector than 120/240, and they are not interchangeable. There are some that are similar, and some people wire the plugs for 3 phase on 4 wires, but in reality you need a 5 conductor wire for correct hook ups, the 4 wire makes you give up either the ground or the neutral.

Also, the math for 3 phase is different than 120/240, so that 6kw of 3 phase is actually only at 16.6 amps.

Kilowatts to amps (A) conversion calculator

Kilowatts (kW) to amps (A) conversion calculator.

www.rapidtables.com

The big problem I see is 3 phase hookups are more commercial/industrial, and usually much higher amperage. Finding a weatherproof inlet box for 3 phase 20 amp will be near impossible, or if it does exist extremely expensive. About the smallest I found were 30 amp flanged male inlets at over $350 each. I bought a connector on ebay to wire onto a pigtail for my generator on ebay, but it was still $100 for a used one.

Hubbell HBL560B9R 60A 120/208V 3PH REVERSED SERVICE Male Flanged Inlet

Hubbell HBL560B9R 60A 120/208V 3PH REVERSED SERVICE Male Flanged Inlet

www.robsindustrial.com

My suggestion for this would be if you are serious about it, get yourself a 10 or 15kw generator and hardwire it into a 3 phase panel in whatever building you are going to have the 3 phase equipment in, and leave it at that. You might actually come out cheaper in the long run with a dedicated setup than if you have multiple wires you have to buy connectors for with each thing, and you eliminate the risk of destroying anything by not having the correct setting for power output on the generator. (the MEP-804 is 3 phase only, so you're likely to find a little better deal on one of them than a 10kw, as lots of people want the 10kw for the 120/240 out, but not many people have use for 208V 3 phase)


As for how long before needing rebuild, depending on how well you take care of it it could be 10k or more hours. Having a backup is never a bad idea though if you can find a good deal on one. There are guys with the MEP002 generators pushing 25-30k hours on them without rebuild. Diesel engines last a very long time.


Since it's new to you you'll want to look through a couple of threads on here.
The quad winding fuse mod is very important, protects the gen from getting toasted if the regulator dies (post #19 has a picture of it, if you don't see the fuse in your unit you should add it ASAP)

Military MEP generator reset information

Howdy, This Technical Bulletin has all the information regarding what happens to a Tier I and Tier II reset. It's a good read to understand what happens and what gets changed, inspected and/or replaced. Covers 2kw to 200kw

www.steelsoldiers.com

and parts and other good information here

MEP-802A MEP-803A Filters and Parts

Howdy, MEP-802a and MEP-803a use all the same filters and such MEP-802A ONAN DN2M 2-cylinder engine (Lister-Petter LPW2) Liquid cooled diesel, aluminum housing MEP-803A ONAN DN4M 4-cylinder engine (Lister-Petter LPW4) Liquid cooled diesel, aluminum housing Oil Filter Spin-On (FILTER ELEMENT...

www.steelsoldiers.com

 

[sl33k3r]

I tell ya. I definitely am glad I asked this question. It is much more involved and expensive than I had originally thought. So far, I do not have any equipment here for building 3 (metal working). My lathe and mill are at another location with grid power. They will stay there for a while. Building 2 is currently a garage with it's own 6.5k Onan gasser. Building 1 is the woodworking shop that is powered by the MEP-802A.

Your recommendations are accepted without reserve. I believe I am going to wait until my large multipurpose shop is built to combine all of my tools and equipment. Buying the necessary wiring, boxes and rods to properly route, connect and ground all buildings and truck/generator for safely being able to use the 802A to power each building separately just doesn't make financial sense. The accountability department/wife, as lenient as she is, might balk at the bill because the buildings will be disassembled once the large shop is built. Throwing away ( or selling on classifieds ) all that material invested in would be a big red flag and a big black hole in the wallet. I will wait.

I was unaware of the different math for three phase power. The results are quite different. While I am not using large motors. Currently, the largest three phase motor I have is 3 HP on my thickness planer. I have no experience starting three phase motors with my generator. It would be nice to hear from others who have experience with three phase motors, the motor's HP rating and the MEP-802A. I frequently come across larger 15-25kW diesel three phase generators and will be looking much more intently for the opportunity to get one and use the MEP-802A as the backup. I was hoping to use the efficiency of the MEP-802A as a power source, but if I may damage it or the motors from motor starts, any money saved in efficiency goes out the window when I have to rebuild or replace equipment.

 

[Coug]

One of the reasons that 3 phase is used a lot in commercial/industrial is lower start surge compared to 1 phase. It's still there, but because you're spreading the load across 3 different circuits that are offset from each other, it's not as high overall.

A lot of industrial and commercial power is billed on 2 different meters rather than 1. The standard power used like in residential, but also a peak meter. While the overall amount of power used might be the same, with the 3 phase the bill will be a lot lower.

The only 3 phase motor I've used with mine is in a 3 ton ECU for the blower fan, and that is negligible power use compared to the heating coils (don't have the aircon side of things recharged yet)

 

[Guyfang]

I love 3 phase. Its all we have here in Germany, and its what the Army wanted for its equipment. It easier on start ups, like Coug wrote. If your buildings are not installed yet, wait, have a competent person install the 3 phase set up and then you get 100% out of your gen sets. If the buildings are not too far apart, I would install a centrel power "Building" and a D-Box to power the whole thing. If its a bit bigger, you could install a back up machine. With larger sets, even parallel them.

 

[sl33k3r]

I really appreciate your input. I'm glad I'm not in a hurry to do anything. I have much to do before I need to make a decision.

I talk to a home shop machinist and he says his power bill is comparable to other home owners power bill and he uses mush more power. He says the USA is messed up because we do not use 220 in all our appliances/tools and possibly should be as GuyFang says about Germany, use 3 phase. It's more efficient.

When we build our house and other buildings, even being off-grid, I think we will be at a minimum 220 V and quite possibly, 3 phase throughout. More expensive to deploy, but I think I will be better off in the long run since I need to be the most efficient as I can being that we are battery powered and solar, be it photovoltaic or wind. I always look for tools and equipment at auction what noone else wants that I can use to my advantage.

 

[Coug]

I really appreciate your input. I'm glad I'm not in a hurry to do anything. I have much to do before I need to make a decision.

I talk to a home shop machinist and he says his power bill is comparable to other home owners power bill and he uses mush more power. He says the USA is messed up because we do not use 220 in all our appliances/tools and possibly should be as GuyFang says about Germany, use 3 phase. It's more efficient.

When we build our house and other buildings, even being off-grid, I think we will be at a minimum 220 V and quite possibly, 3 phase throughout. More expensive to deploy, but I think I will be better off in the long run since I need to be the most efficient as I can being that we are battery powered and solar, be it photovoltaic or wind. I always look for tools and equipment at auction what noone else wants that I can use to my advantage.

Throwing solar/battery/inverter into the mix changes things a little.

With the U.S. residential standard being 120/240V, most of the off grid inverter systems are 120/240v. There ARE 3 phase units available, but they are less common. This means it will be higher priced, and if anything decides to stop working you're unlikely to find anything local to get it up and working quickly.

I'd say keep all the appliances 120v or propane powered whenever possible, because you can run 120V gear off of a 208 3 phase setup (any phase to ground will be 120V), but not every piece of 240V equipment/appliances will work on 208v (some will, going between 2 of the 3 phases to get single phase 208, but not all).


If you don't plan to do the solar/battery/inverter install yourself, I'd recommend finding whoever does it in your area and discussing it with them, to see what is actually available and what type of pricing it will be.


On a side note, the reason for using higher voltages isn't efficiency, it's the fact that a smaller wire can handle the same amount of amperage no matter what the voltage is (as long as the insulation is good) so a 220v system uses smaller wiring, and copper is expensive when you have to run a lot of it. The overall efficiency of single phase is the same at either 120v or 220V (or close enough not to matter much). It's the Watts that do the work, the volts and the amps are just how you make the Watts.

 

[Guyfang]

Throwing solar/battery/inverter into the mix changes things a little.

With the U.S. residential standard being 120/240V, most of the off grid inverter systems are 120/240v. There ARE 3 phase units available, but they are less common. This means it will be higher priced, and if anything decides to stop working you're unlikely to find anything local to get it up and working quickly.

I'd say keep all the appliances 120v or propane powered whenever possible, because you can run 120V gear off of a 208 3 phase setup (any phase to ground will be 120V), but not every piece of 240V equipment/appliances will work on 208v (some will, going between 2 of the 3 phases to get single phase 208, but not all).


If you don't plan to do the solar/battery/inverter install yourself, I'd recommend finding whoever does it in your area and discussing it with them, to see what is actually available and what type of pricing it will be.


On a side note, the reason for using higher voltages isn't efficiency, it's the fact that a smaller wire can handle the same amount of amperage no matter what the voltage is (as long as the insulation is good) so a 220v system uses smaller wiring, and copper is expensive when you have to run a lot of it. The overall efficiency of single phase is the same at either 120v or 220V (or close enough not to matter much). It's the Watts that do the work, the volts and the amps are just how you make the Watts.

Got to agree with this info. And its gotten so bad with copper prices, that the copper usage in the PF, (Photoelectric world) has gone to about 0% here in Germany. Aluminum, that's about all that's used now a days. We used to make fun of the East Germans for using mostly Aluminum, but the jokes on us. It takes a while to get used to be good at hooking up Aluminum cables, (I am not talking about small wires) but once you get the hang of it, I like it better. You have just never lived until you have run 300-400 meters of 240 mm (600 MCM) through a building and then hooked it up! Go to the gym for a work out? Not even close!

 

[DieselAddict]

At my place the MEP831 is now all I need. The solar/battery system provides the surge loads and the short term high power loads. The 831 just recharges the batteries when the power demand is below its max output.

Total game changer.

 

[Daybreak]

Howdy,
3 phase note:
You need to ensure the rotation of phase. You don't want your stuff running backwards and blowing up.

 

[sl33k3r]

Northern NY in summer, with a 1800 photovoltaic watt system providing electric cooking and AC during the day (with vigilant timing) to keep our camp cool enough until dinner time. Induction cook tops are wonderful! Winter is another story. We receive little sun, a good little generator is a necessity. I currently run a 2k Honda for the camp to charge batteries and use another 2.3kW portable gasser for tasks about the property. I would love a little 2-3kW diesel generator for charging camp batteries when the sun isn't behind cloud cover. I do have a masonry heater to provide for heat and cooking in the winter to alleviate the electrical demand.

I'm looking at auction a couple older military generators. I'm unsure of the model as it's not stated. But they are single cylinder Yanmar diesel with 24 VDC start which pairs well with my battery arrangement. The issue I may have with those would be the cold starts. I don't have room for the batteries or the generator inside. Like last night, it was -11 when I had to start my Honda. With three pulls, it was going. It runs for just over eight hours on a bit less than a gallon of gas. Maybe I'm better off with gasoline generator for winter battery charging. They start easy and are pretty economical. I'm just unsure of longevity. I change the oil regularly and use synthetic oil. Plus, I can easily carry them wherever they are needed. Also, my wife can carry them...even if I don't put them on wheels.

As far as US standards, it's not local availability that concerns me. This is a poor rural area half a day drive to anywhere that may have solar equipment. When I want solar related equipment, I have to order it. I can order them from anywhere in the world. If I have an item that is crucial, like an inverter, I double what I need and use the same inverters in more than one place so I have a backup. Just be sure to get the right size for the larger demand. I currently have two 3kw inverters supposedly capable of 6kw surge (I have not tested it's limits). I most likely can use smaller inverters fall through spring to be more efficient since my current requirements are far less than when I purchased these. My current inverters use 25 watts standby. Current usage is about 400 watts with everything on that we use in the winter. A much smaller inverter will be more adequate for this type of demand.

But I am getting away from the reason of this post.

Currently, I have no plans for three phase inverters. I do go back and forth with the idea, but I don't have a desire to purchase new retail systems for three phase inverter power. I do, though, look for three phase commercial battery backup systems in the 10-15kW range that are being replaced and auctioned. Typically, these systems are for buffer power to clean electricity and provide power in the event of power outage until generators can start. The designed battery capacity of these systems is not to sustain power supply for long periods of time.

Even if I could find one of these backup systems, I would still have to source adequate potential difference storage, be it chemical as in a battery or a elevated mechanical storage where a solid could be dropped in a controlled fashion which would turn a generator head. The backup system then provides a buffered, clean supply of power. In the case of the mechanical storage, if power was a high priority, batteries would still be required to supply power for short-term power until the mechanical system could take over. But for my purpose, provided I have adequate potential difference storage, to eliminate the battery cost, I'm sure I could wait until the mechanical generator could engage. This system would take a LOT of material and a large tower to fulfill my requirements.

If you cannot tell, I am quite a bit scatter brained. I'm all over the place with my thinking. But it does allow me to review many hair-brained schemes and take what I need from each to satisfy my needs.

To review my current and most lucid plan:
The multiple hookups are prohibitively expensive and my buildings are too far apart to economically wire together. I am keeping the current multiple generator scheme as it is. After the house is built, the single large workshop to locate my woodworking shop, metalworking shop and garage is to be built. I will likely purchase a 10-15kW three phase generator and use a 2001 F350 4x4 to mount the backup MEP-802A, a 1944 Lincoln 250 A DC welder powered by a Wisconsin VF4D, a 60 gallon 2 stage Brunner air compressor powered by a 12 HP B&S donated from a snow blower (I wanted the 12VDC and 120VAC electric start) and a well stocked tool box. This truck will allow me to go anywhere make repairs.

 

[sl33k3r]

I see a trailer mounted 30kw military generator . This is much larger than I need, but was wondering what the fuel consumption of such a generator would be at say 1/4 load? It's current bid of $1,500 seems very reasonable if you need a generator of that size. AND a trailer.

EDIT:

Sorry, a quick search and I found what I might be looking for. I'm not sure if it's the identical unit, but it cannot be far off. 2.6 gal/hr must be full load,

 

[Zed254]

Read up on Wet Stacking of Diesel Engines: https://www.ckpower.com/wet-stacking-avoid/ and https://www.wpowerproducts.com/news/diesel-engine-generator-wet-stacking/ .

I was able to observe evidence of wet stacking my 802 in 65 hours of run time at around 20% load with my camper. I bought too much generator and did not realize the camper was 120 v single phase, NOT 240 volts. I'm delivering 52 amps to a small camper. After 65 hours I noticed a wet fuel stain on the top of the unit next to exhaust stack. My solution....and it works well.....was to add 2 electric space heaters of 12.5 amps/each that heat up the winter nights. This loaded the diesel engine up to 60-70% and all is as it should be.....now.

I'm suggesting that you buy the right sized generator so you don't wet stack the engine.

 

[sl33k3r]

...I'm suggesting that you buy the right sized generator so you don't wet stack the engine.

Thank you for your post. The more I read, the more I understand. I just finished a post about fuel consumption between the 802A and 803A. in this post,
Korgoth1 in another post that states:
"In my experience, the gallon an hour for every 10kw load has been very close. So close in fact you can take the price per gallon, say $1.95 for example, and know that it is going to cost you $.19 cent per kilowat to produce your own power at that fuel price.
People here get wound up thinking a larger unit will bleed them dry, if you pull a 2kw load overnight, it is going to use very close to .2 gallon per hour regardless if it is the 02 or the 05 units, with the 05 using just alittle more(it would take a month of running to notice a difference)

Bottom line, load=fuel
The only problem is ensuring you do not wetstack."

By this reasoning, the 803A wouldn't necessarily cost me more to operate as the fuel demand for my electric demands will be negligible between a 805A ( one of my previous posts) and 802A as the cost of fuel is on a per kW basis.

While this leads one to believe the larger generators (within reason) can be as efficient as smaller ones, the caveat is wet stacking. My generator has perhaps 30 hours on it now and I know I have not hit 50% load yet over perhaps 2 dozen starts. I need to have a more strict regiment to ensure my generators longevity.

Wet stacking makes me rethink my generator size requirements or my method of using the capabilities of the generator. I find load banks (to my understanding) wasteful as they don't appear to use the heat they produce. We will heat with water. Even in the summer, I require warm water. If I am to need to use a load bank to exercise my generator(s), I might as well heat my water. I have two 5,000 gallon tanks to hold warm water for my house and greenhouse heat. The water is heated by solar collectors and occasional firings of a large wood boiler. Our hot water needs need to be met year 'round but I believe between our wood boiler and the solar collectors will provide enough hot water. If I have more hot water than I require, maybe I can use the extra heat to warm the earth under the greenhouse. While I'm not saying that the generator would provide a significant amount of ground warming, but if I had the system built in prior to building, it will be easy to "plug into" the system by using the occasional wet stack prevention procedure to warm the water and eventually the earth under the greenhouse year 'round. I don't want to heat the ground under the house since our root cellar is in the basement. Most likely, I should warm the earth beneath the workshops as the costs incurred will be much less than the wire to transfer the electricity or pipe and insulation to move the heated water to the greenhouse.

Now I don't feel so bad about using a larger generator than I need for my needs since I may have ample power when I need it and can use the anti-wet stacking maintenance procedure to provide a service for me without believing I'm just sending the heat created by load banking into the air. Though, I'm mostly thinking a 803A or 805A might be most suitable if not another 802A. I believe I can set up an automatic timer and shut-down electronic controlled shut-down procedure with a reasonable effort. All I would need is a good water heater and circulatory pump. I am currently looking at a used three phase 45kW 208V heater that can draw up to 125 Amps. Granted, I don't need that full draw. Like Coug, above, I can use only the proper number of the twelve circuits to get the proper amount.

Sound reasonable?

 

[Zed254]

I found my 803 is a little large for my home backup unless I'm running my clothes dryer but I'm more worried about damaging my equipment than calculating the per Kw cost to run a generator. With my camper and 802 it costs me $1/hour in fuel to stay warm and cozy on a cold night. And that's with those 2 extra space heaters warming up the woods. Tally your expected loads to determine required generator size needs. And I really wish I did not need to run my clothes dryer to get that 803 into the engine's 'comfort range'. I am confident that with load management my 802 would do just fine as a home back up generator.

I run a 2 or 3 hour test every 3 months with an electric stove (my load bank) at around 95% power factor on my 803 to make sure all is well. I don't really worry about the loss in energy of a 3 hour run heating a stove in my driveway. I look at it as a cost of maintenance.....like changing the oil and filter every 250 hours.

Your building project's capital costs need to be factored into your $/kw calculations, too. 3 phase 30kw generators take larger copper conductors and more of them than an 803 or 802 operating in single phase. And you will be heating up a lot of water during your quarterly machine exercises (think blowing out all that wet stacking) to maintain that big generator. I'm guessing that you are thinking of running water pipes under ground to "warm the earth beneath the workshops ". This will require capital spend on a pump, a spare pump, electrically heated water tank, lots of pipe, and labor to install it all. Interesting project but I think pretty expensive to satisfy the need to use up power.....like I do with my 2 space heaters when camping.

One large generator to power your entire facility - home, work shop, out buildings - may be cheaper than multiple generators. However, 3 ea MEP802s will give you the flexibility of moving one machine out for maintenance while replacing it with a good runner. I like redundancy.....and I really don't know squat about 3 phase power. Keep us posted on how it all turns out.

 

[Coug]

It takes something like 16k BTU of energy to make 1KW of power (at least for natural gas and propane generators). The main reason why fuel use increases with size is the amount of fuel burned just to keep the heavy mass of the engine crank, pistons, flywheel, generator rotor, and accessories/parasitic loads moving. The bigger the unit, the more fuel used just to keep things moving.

If you're going to run it for long periods of time with minimal load on it, you are better off with a smaller generator sized just to your needs.
If a little wastefulness isn't a big issue, getting a gen a bit larger than your potential max load isn't going to be an issue. That being said, it's usually better to have a little too much generator than not enough, and I don't know how big or how much equipment you are planning to have in your shop, so a little bigger than needed might be best for later on if you pick up some equipment that needs more power just because it was less expensive than a smaller unit (surplus gear can be funny like that sometimes)

Since you are planning on a shop with a bunch of equipment, consider how many things might be operated at the same time. I know for our wood shop here (hobbyist/semi commercial) we could have as many as 4 or 5 things running at once with 2-3 people in the shop, because of things like dust collector, joiner, table saws, radial arm saw, planer, as well as all the smaller equipment. Some equipment is used enough that it doesn't get shut down to use something else for a couple minutes, just because it takes a little bit to get up to speed.

It's not like you're going to start wet stacking immediately when running it under a light load. It can take many hours or even days worth of running before it becomes noticeable. At that point you run it under heavy load until it clears off, then go back to whatever load you want until it happens again.

One thing to consider for the MEP-803 though is it uses a lot of the same parts and filters as the 802 does, so that gives you some redundancy right there, and fewer parts you have to stock.