Connected my MEP-803A the proper way as my home standby generator... Install pics...

[Glockfan]

Nice installation Glockfan! Thank you for documenting and sharing too! What gouge wire you have used between the generator and the manual switch?

I believe I used 4AWG copper...

 

[lonesouth]

Nice installation Glockfan! Thank you for documenting and sharing too! What gouge wire you have used between the generator and the manual switch?

I used 4awg for the hots and neutral, and 6awg for the ground. Depending on run length you may need to size up.

 

[Guyfang]

I put up photoelectric, (among other things) for a living. When the Master Tech figures cable size, and a 6 AWG is good, we use 4 AWG. The extra cost, is easily justified by the peace of mind of the owners, and our company. The first tine I saw this in action, I knew I had found a new home. My kinda people. Every place I had worked before, had always cut corners. I hate it.

 

[Glockfan]

Mine sits about 30' from the transfer switch. I have load tested my particular generator to produce 15,200 watts for about twenty minutes before going out on an overload switch. I figure that's about 63A doing the math. These units will produce more power that folks give them credit for and they are not nearly as loud as the old air cooled Onans. I am a big fan of the water cooled Lister Petter diesels. We ran these things in the desert dirt nonstop only shutting them down once a month to change the oil...

The crazy thing is, I have lost power here for about four hours since installing my setup... I fire it up now about once every five or six weeks and let it run up to operating temperature then shut it down... It's comforting to know my A/C will still be running if we lose power. It's hot down here.

 

[CJU]

I decided that this is going to be my 15 year home and that we are done moving so I wanted a more permanent installation of my 10kW MEP-803A. I wanted a safe and legal means of connecting it directly to my service panel so that my wife can just throw one lever to restore power after starting the generator up. It made the most sense to me to go with the DPDT safety switch. The county inspector and GA Power were actually surprised to see that I went this route and actually left here smiling... Here are some pics of the finished job.

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Thanks for the great info. I am setting up a home power unit and leaving the unit on my trailer so I can use it at my farm also. I will just hook it up when Power is out. The electrician didn't unhook the bar from ground to neutral... I do have a ground rod I hook it to when parked for home power. Should I unhook the bar ( G to N) when using gen for home power? Also, do your Hertz drop when you turn on a large draw like a dryer? I think my Hertz drops to 57 or 58. Is this okay? I trust the electrician, but he had never seen a MEP 803a before. So not sure if he knew all the little issues. Great job on your set up.

 

[Glockfan]

Thanks for the great info. I am setting up a home power unit and leaving the unit on my trailer so I can use it at my farm also. I will just hook it up when Power is out. The electrician didn't unhook the bar from ground to neutral... I do have a ground rod I hook it to when parked for home power. Should I unhook the bar ( G to N) when using gen for home power? Also, do your Hertz drop when you turn on a large draw like a dryer? I think my Hertz drops to 57 or 58. Is this okay? I trust the electrician, but he had never seen a MEP 803a before. So not sure if he knew all the little issues. Great job on your set up.

I usually purposely keep mine adjusted up to about 62 Hz in anticipation of load draws like the heat pump, etc. once I am running at 50%-75% load then the Hz normalizes to around 60 but it fluctuates with varying current draw. Most modern electrical devices will function fine at 50-60 Hz.

Regarding the ground bar, somewhere back in this thread we talked about creating a ground loop and it was suggested that I not use a ground rod in a permanent installation like mine, therefore, I have since removed my connection to the rod and also isolated ground from neutral by removing the copper bar between "N" and "G" to prevent a loopback. My setup used the homes existing ground rods. In your case, as long as your setup is temporary (on the trailer), I would use the rod and keep the neutral and ground bound.

Please chime in, those of you that do this for a living... My advice should be considered "tips" and that's about it. I could be wrong.

 

[lonesouth]

here is a good write up on grounding

http://www.ecmweb.com/content/bringing-grounding-down-earth

 

[DieselAddict]

From a code perspective it's not allowable to have the neutral and ground connected in more than one location (temporary or not). From a practical standpoint it's a very low probility it would ever be the source of a problem.

 

[CJU]

Thanks for the tips. It helps reduce the unknown for a newbie like me. You started a great thread here. Lot of info in one place. I will set the Hertz at just above 60 and watch it with a big pull on it. There seems to be no pull on the engine. The unit is much stronger than I thought. The electrician was impressed.

 

[Another Ahab]

Thanks for the tips. It helps reduce the unknown for a newbie like me. You started a great thread here. Lot of info in one place. I will set the Hertz at just above 60 and watch it with a big pull on it. There seems to be no pull on the engine. The unit is much stronger than I thought. The electrician was impressed.

When everything is hitting the fan, you want ALL your hardware operational:

- It's MilSpec, so it sure BETTER be robust.

Right?!

 

[jimbo913]

Each line on the Hz gauge represents 0.5 Hz. Did you think each line was 1 Hz?

 

[Daybreak]

Howdy,
You are probably better off running you house as you would and then set it to 60Hz. That way the swing will be in your sweet spot of use. When no power draw is there, you might be around 61.5Hz running with no draw. If you look at any of my videos, you will see at first start, and no-load, I have all mine around the 61-62Hz. I try to keep a average percent used anywhere from 50%-100% usage. Always double check the gauge with a real multi-meter to insure its reading correctly volts and Hz

Grounding=
in the middle of a field, ground rod in the ground and wired to ground lug. Bonding strap in place.

connected to house electrical system, 4 wires connected from house to generator lugs, bonding strap disconnected. You are using the house electrical panel ground.

 

[jimbo913]

"connected to house electrical system, 4 wires connected from house to generator lugs, bonding strap disconnected. You are using the house electrical panel ground."

I believe this is where you have to be careful as some switches disconnect the neutral. It is my understanding that the statement is true provided that the wires run uninterrupted to the panel/breakers, like a typical interlock setup.

 

[Another Ahab]

Howdy,
You are probably better off running you house as you would and then set it to 60Hz. That way the swing will be in your sweet spot of use. If you look at any of my videos, you will see at first start, and no-load, I have all mine around the 61-62Hz. I try to keep a average percent used anywhere from 50%-100% usage. Always double check the gauge with a real multi-meter to insure its reading correctly volts and Hz.

Is that kind of the rule-of-thumb for optimal (+/-) generator use:

- To be running (ideally) at 50% of the unit capacity?

 

[ELPasoTom]

Good advice on the load and frequency

When my 803A is running our house it is typically at 75% and sometimes will use 100% for a small time. My hertz does drop a bit under load, so I may too take it up to 61% unloaded. Sounds like reasonable advice although none of my household appliances complain at 57-58Hz. Here is a typical load:



Thanks
Tom

 

[rustystud]

Is that kind of the rule-of-thumb for optimal (+/-) generator use:

- To be running (ideally) at 50% of the unit capacity?

Actually the closer you are to 100% the better. Diesel engines perform better when they are running at their factory designed peak for ultimate performance and economy.

 

[Another Ahab]

Rustystud, Brother, you are a wise man and have darn near seen it all.

It feels sort of like sitting in a classroom with a front-row seat in these threads sometime.

It's great to have you (and the many other "battle-hardened" old hosses like you) around here.

 

[steelydan]

Hi.
So if it's a 10kW generator, then my math is telling me that at max (10kW) usage, I'd need a ~85A wire (10,000W/120V = 83.33A) If so, for a distance of about 20 feet from my generator to the connector on the house, what wire should I use? My Google-fu is finding that it should be 3GA wire. Is that what you guys are using, in anticipation of max loads?
TIA!

 

[mingram]

So I power the house with 242volts as that is what FPL provides to my box. I use a 4 core 6 ga wire (L1, L3, Neutral and Ground). The spec for the wire was 600v/45amps. Hope this helps. These Generators can actual produce more than 10KW for brief periods I have seen it push 14KW on occasion when the AC cuts in.
Here is the link on Amazon if this helps:

https://smile.amazon.com/gp/product/B00LI4I5JU/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

This just ran for 7 days straight as we lost power due to Hurricane Irma. It had no issues with the load on this cable. Powered the whole house must have had 10 neighbors asking about the MEP-803a and how to get one.
good luck.

m

Hi.
So if it's a 10kW generator, then my math is telling me that at max (10kW) usage, I'd need a ~85A wire (10,000W/120V = 83.33A) If so, for a distance of about 20 feet from my generator to the connector on the house, what wire should I use? My Google-fu is finding that it should be 3GA wire. Is that what you guys are using, in anticipation of max loads?
TIA!

 

[Glockfan]

So I power the house with 242volts as that is what FPL provides to my box. I use a 4 core 6 ga wire (L1, L3, Neutral and Ground). The spec for the wire was 600v/45amps. Hope this helps. These Generators can actual produce more than 10KW for brief periods I have seen it push 14KW on occasion when the AC cuts in.
Here is the link on Amazon if this helps:

https://smile.amazon.com/gp/product/B00LI4I5JU/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

This just ran for 7 days straight as we lost power due to Hurricane Irma. It had no issues with the load on this cable. Powered the whole house must have had 10 neighbors asking about the MEP-803a and how to get one.
good luck.

m

I ran mine on a load bank for 20 minutes at 15,400 watts. Wired for 240 volts, a 6 ga. wire will suffice. It’s what I am using...