HVAC advice - 10kw Heater kits and MEP803

[spotrep]

Howdy gents!

I want to prod the clever guys on this forum for advice.

I have an 803 im using for home backup. Im in Texas, and like many we suffered through the terrible winter storm in 2021 that led to the death of people and caused 195 billion + in property damage.

Because of this experience (and 2 young children and a wife in my house) I decided to ensure that my family would be comfortable while the world around burned (of froze).

The MEP is all ready to go an powered the home for 12 hours after a bad wind storm already (wife was happy).

HOWEVER, my concern is winter and how im going to keep the home cooled. The generator runs the heatpump with no problems, but im sure the 10kw heat strips, on top of other household loads will be difficult for the MEP.

Do any of your have a solution to this problem? Of course i could run a few space heaters. But id like a more permanent solution. The home is 2400 sqft. I considered reducing the size of my heat kit to an 8 or 5kw kit, i considered a 2 stage heatkit (running on 5kw while on gen and 10kw on grid), or have an appropriately sized additional heat kit and design the system to switch over seamlessly.

Let me know what yall think!

 

[spotrep]

also for those interested here is the heatkit i have installed now: https://www.grainger.com/product/CA...suggestConfigId=7&ts_optout=false&tier=Tier+6


the air handler is: pf1mna048 Im unable to find info on it online

 

[LuckeyD]

Good Day: Not intelligent, but here are a few tips. MEP803 is just a 10KW gen. If everything is 120/240 in your house, set it on that. You get the full 10KW but be careful not to load only one hot too much. Causes many things to occur that are not good. A MEP-1041 is an AMMPS gen. It is rated at 10KW but it uses the same main gen as a 15KW. During a class and after we built it back up from the skid, we put a 12.5 KW on that main gen and engine at it held for 45 minutes before we cooled it down to shut down. A 10 Gal bucket holds 10 Gallons. May want to look into solar panels and battery storage with inverters for a lot of small stuff while the 10K gen runs the heavy stuff. A 15KW will do all of it, but you got to budget.

 

[spotrep]

Good Day: Not intelligent, but here are a few tips. MEP803 is just a 10KW gen. If everything is 120/240 in your house, set it on that. You get the full 10KW but be careful not to load only one hot too much. Causes many things to occur that are not good. A MEP-1041 is an AMMPS gen. It is rated at 10KW but it uses the same main gen as a 15KW. During a class and after we built it back up from the skid, we put a 12.5 KW on that main gen and engine at it held for 45 minutes before we cooled it down to shut down. A 10 Gal bucket holds 10 Gallons. May want to look into solar panels and battery storage with inverters for a lot of small stuff while the 10K gen runs the heavy stuff. A 15KW will do all of it, but you got to budget.

thanks for the reply!

I’ve since discovered diesel heaters, commonly referred to as parking heaters. I’ve fashioned 2 to enable me to deploy them outside and have flexible ducting for the return and supply pipes through a window. I think those along with load balanced space heaters will enable me to keep the home at a safe temperature. Luckily I haven’t needed to use any this winter!

however, batteries are in the future. I’m liking all the eg4 stuff right now. Just not ready to spend money on it yet

 

[swbradley1]

MEP803 is just a 10KW gen. If everything is 120/240 in your house, set it on that. You get the full 10KW but be careful not to load only one hot too much. Causes many things to occur that are not good.

Not sure how they do it in Germany but every panel I have worked on as an adult splits the load for you. The lines come into the panel at the top and get distributed via the metal tab bars coming out the bottom of the top breaker.

You can see it in the pic below. The breaker at the bottom is plugged in and pulls from each side of the line. That being said I guess it would be possible to use every other breaker slot going down and unbalance the load. Not likely though.

They way they are setup you can put breakers all the way down one side and the load would still be balanced for the most part. Elegant design to prevent people like me from screwing it up.

 

[LuckeyD]

Good Day: There is a manual Guyfang posted in Tech Manuals, Power generation in the Theater of operations. Recommend reading it a bit. 2nd year EE courses when you design gens is where we touch on this. On the 5 and 10KW Gen sets there is a voltage selector switch. TQGs call it S8. It does wonderful things if you set it up before you start the thing. Here is an example of what it does: On 120VAC, (Delta configured main gen) all power is sent to L3 and Neutral so you get all 10K on these. If in 120/240VAC you get 5000 wats on L3 and L1 to neutral each. So on your Square D panel, if you put the water heater and Stove on one leg,(L3 as an example), you come real close to overload on that leg at dinner time with baking going on and the water heater is in full swing. The regulator only senses L3 to Neutral so ensure your max load is there or you get brown outs if max load is on L1 and a 60W light is on L3. If you use 120/208VAC setting you get about 3.3KW on each leg and the main gen is in the Y configuration. The main gen does not compensate, but gets real warm if you get close or overload one leg. This causes a winding swell, which gets that winding real close in the space between the rotor and stator and causes a birds nest of copper to form and possible generator lock up. So a panel does not always split things up evenly, but the one operating the gen, or installing the panel must do a little math of the over the thumb type stuff. I used an AMP Probe a lot and found many systems unbalanced and having issues. Moving loads around a bit and proper setting of the S8 and they even had enough left over to run the laptop, game, or even the coffee pot. MIL STD gens were designed at about 80% of the electrical machine production, but the TQG did not have this and when it says it is a 10K Watt, that is all there is, and coil heating does occur if overloaded. I do not recommend relying on a very old k8 to save you. It probably has many trips to the wash rack behind it.

 

[msgjd]

View attachment 941454

Just a note of detail , the "F12" Bonding Bushing (aka "grounding bushing") is only required on concentric/eccentric knockouts when using metallic raceways, ie; steel or aluminum conduit

During my years as a contractor occasionally tasked by mills to troubleshoot/repair, I had seen a few instances where a GB was not used and a phase fault occurred , which burns out the KO rings.. On 480V, the arcing and smoke must've been spectacular to see .. The scarier part was a time this happened and I discovered the steel building's skeleton (to which all the conduits are basically secured to and run along) was not directly grounded (bonded) with its own bonding conductor

If one is going to use SE cable, MSHA-type flexible cable etc, or pvc conduit to feed the panel, a GB would be totally redundant (thus silly )

Section 250 ("Grounding & Bonding") of the NEC covers this and much more, Particularly 250.9x onward. IMO, Section 250 is the most important section of the entire code book

 

[LuckeyD]

Good Day: Most folks don't have conduit in their homes or even in their barns. Fun stuff to work with. What most folks do not know is the ground lug on Military gens is bonded to the gen set frame, engine, and the main gen on most gen sets they get from military sales. This has been in place since the Steward-Stevens 45KW days and is a public law PM MEP has to follow in spec requirements documents. The neutral to ground bond is there because some systems needed this broken so it did not cause issues in the power systems for that system. Usually it is in place unless that system states to remove that link on dedicated power, and a note is in there not to connect other power requirements to this dedicated system. Power companies install at the transformer a ground and it is bonded inside the transformer to the neutral for homes. State dependent, small installations like homes may or may not require a bond in the main breaker panel. Va, Maryland and DC required it when I had a license there years ago. Resolves the floating neutral issue. This issue pops up frequently in lose soil that is dry and causes power issues such as one I had in Turkey at a FOB there. A star ground and a #6 run to the light pole and fence pole brought things to a point the commo site could be hooked to the power network from prime power. It is also found in large parking lots.

 

[msgjd]

Good Day: Most folks don't have conduit in their homes or even in their barns.

If you mean metallic conduit, you are correct ..

Here in the rural/ agricultural areas of Northeast US, Non-metallic conduit is found on services to about 50% of homes and a higher percentage at barns, garages, and small businesses. Metallic conduit is primarily found on most services to larger businesses, and some small businesses.. Metallic conduit can also be found as part of a residential service conduit installation in certain situations

The use of conduit and whether it shall be metallic or non-metallic does not care whether it's residential or larger. It depends on the NEC, AHJ, and the risk of physical damage at the location

I was pointing out that the illustration shows a metallic conduit installation but it does not say it. Pointing this out for the few, if any, who might think the illustration is a fit-all example