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

[ZackMan]

Glockfan,

I believe the copper bar I refrenced was the 90 degree angled bar attached to the bottom of the neutral and ground generator terminal lugs. However, upon further research I believe I found a "vertical" copper bar attached on right-side of the terminal lug plate at the bottom; therefore, it would not be the one I earlier described.

ZackMan

 

[mrheiser]

You may want to check the NEC on grounding of generators. Your transfer switch doesn't switch the neutral and with that you don't bond the equipment ground at the generator end with the system ground. You should remove the ground rod wire at the generator end from the GND terminal and connect it to the equipment frame only. Also check to see if there is continuity between the GND term and the equipment frame. If so you need to remove the internal jumper to isolate the GND term from the equipment frame.

Looks great otherwise.

I'm a little confused with the wiring configuration regarding ground and neutral. Right now my home electric panel has ground and neutral bonded. I wired in my 803A generator to my home using two 60 amp breakers and an interlock kit. The neutral and ground inside the electric panel aren't switched when going from commercial power to generator power. How should my generator look regarding the bus bar and also the ground? Should I remove the bus bar on the generator bonding ground and neutral? Also should I have my grounding rod wired to my generator frame or the ground lug? Just a little unclear on this. Thanks for your help.

 

[DieselAddict]

I'm a little confused with the wiring configuration regarding ground and neutral. Right now my home electric panel has ground and neutral bonded. I wired in my 803A generator to my home using two 60 amp breakers and an interlock kit. The neutral and ground inside the electric panel aren't switched when going from commercial power to generator power. How should my generator look regarding the bus bar and also the ground? Should I remove the bus bar on the generator bonding ground and neutral? Also should I have my grounding rod wired to my generator frame or the ground lug? Just a little unclear on this. Thanks for your help.

Since you already have a ground/neutral bonding point in your home system you would remove the bonding bus bar in the generator. You are now required to do a 4 wire hookup from the generator connecting both hots, the neutral, and the ground to the corresponding conductors on the house.

Its OK to drive a ground rod at the generator but its not specifically required by NEC. Local codes may or may not require it. You'll have to find that out from the local inspector.

 

[tim292stro]

Neutral is bonded to ground in one place only on an NEC compliant residential/commercial electrical system. This single bond is to ensure that any faults will clear when either the current from line-to-neutral via ground is too high in a non-GFCI circuit (overcurrent), or by ground fault (rating of the GFCI breaker 6-20mA depending on application) when GFCI is applicable under NEC.

The system ground rod is intended to pull the neutral line of the secondary side of the power company's transformer to a safe local level - without any ground, the secondary side could float to a voltage where line-neutral is 120V, but line/neutral to earth upwards of >1kV (zap) as air moves over the wires giving them a charge (just like ragging your feet in wool socks over a carpet).

This is completely separate from a lightning ground system... That requires being bonded to the system ground to prevent lightning from jumping into the home's power system, but it also requires its own ground array and conductors separate from the rest of the electrical system ground.

Having many ground rods on a system ground does not "hurt" the fault clearing effect as the earth does not create a meaningful effect on the power circuit, since the circuit is completed from line to neutral, not line to ground. The only circuits that are completed from earth to an electrical system is ambient air charge (static/lightning) and RF. If you have your generator any appreciable distance from your house and its system ground, an extra ground rod at the generator will help with dissipating lightning strikes on the generator, near the generator.

If you're worried about multiple ground rods on your home's system, think about this - each of your neighbors are also required to have a system ground rod and neutral bond at their main point of entry under NEC, and power poles will have a ground rod to neutral every so often. The system is already done this way as the power company does not distribute "ground", only power

 

[mrheiser]

Thanks for all the information guys. I really appreciate it. Got all the wiring done and tested it out. Works like a champ. I used 50' of 4 gauge 4 conductor wire for the hookup. Also drove an 8' grounding rod and hooked it to the chassis ground lug.

 

[tim292stro]

...an extra ground rod at the generator will help with dissipating lightning strikes on the generator, near the generator...

I realize I should also caveat, that it won't make enough of a difference having a ground rod near the generator if it is directly struck by lightning - anything attached to the generator's electrical system will be cooked. For true lightning protection, you want to look at installing a lightning protection system (and that's only if you have a good reason to due to site risk).

 

[DieselAddict]

Thats the trick with lightning protection.. If you are directly stuck you are uh.. What rhymes with struck? Oh yea, Screwed..

The best you can do is to make it harder for it to get inside if you take a strike nearby. I have an arrester on my panel outside and I know it has saved my bacon more than once.

My advice - Buy one. Buy it now. One of the best $75 (or so) you can spend to protect the stuff in your house.

 

[CT-Mike]

Chris,

Can you provide a link to the arrester you have?

Thanks.

 

[DieselAddict]

Well, Classic Medico Overkill being what it is I doubt you want to follow me down that rabbit hole!

Something like this is a decent practical unit:
http://www.amazon.com/Square-Schnei...d_cp_23_2?ie=UTF8&refRID=0R6B4JXFBDRMWP0KTH7R

BUT - If you want to join me and bathe in the overkill:
https://www.platt.com/platt-electri...ount/Eaton/CHSPT1MAX/product.aspx?zpid=848498

 

[CT-Mike]

I don't mind overkill, if I did I would've went with a Generac from Home Cheapo instead of the -803.

Considering the the amount of money I have in computers and home theater equipment I don't mind spending a little extra for peace of mind.

Thanks for the link.

 

[DieselAddict]

I do most things to industrial standards. I don't apologize for it as much as I used to.

 

[CT-Mike]

The one you went with appears to be rated for 45 kAmps, whereas the Square D is rated for 80 kAmps. What makes your choice better?

Thanks.

 

[DieselAddict]

That's a really good question. When you are looking at a surge rating there are a couple of numbers to consider together. One is the Surge Current Per Phase. On that one the Square-D looks good at 80kA where the Eaton is a little lower at 50kA (the Ultra is rated at 50kA where the MAX is 45kA). The second number to consider is the SCCR which is the total amount of (short circuit) energy the unit can handle. The Square-D here is spec'd to handle 25kA. To me this says that the true limit of the device regardless of the single phase current rating is 25kA. The Eaton on the other hand is spec'd to handle a SCCA of 200kA. That is a benefit especially if you are getting a surge on multiple lines at the same time which is most certainly going to be the case.



https://images-na.ssl-images-amazon.com/images/I/31p-7-nTLPL.png

Edit - Both provide protection across all lines and multiple modes (current paths). That goes into the plus column for both.

 

[Guyfang]

Chris, here in Germany, almost EVERY roof has a lightning arrester system, and it does indeed help a lot. BUT, if you DON'T have one, the insurance will not pay a dime. No ifs, ands or buts. So most people install one just to make sure that the insurance pays off. When we install a photo electric system on a roof,we avoid bonding to the existing roof top lightning arrester system. My old master electrician always called lightning arrester systems, a lightning ATTRACTING system. He claimed that your chances of getting hit were higher then if you didn't have one. And the grounding of everything in the house (like water pipes, heating pipes, etc.) with the lightning arrester system simply made it easier for you to destroy EVERYTHING electrical in the house. Having said that, I have a lightning protection system also.

 

[CT-Mike]

Thanks for the additional info Chris.

 

[AOR]

Nice Job! Sorry if I missed this but I just purchased one of these this week without doing much research. All this is new to me. What gauge wire was used from the Generator output? Based on some load test videos I have been watching it seems that these can put out over 100 amps when combining the output amp readings taken from the leads. Do you think the MEP-803A would run an electric heat pump? According to the information on the heat pump the heater grid alone uses 9.6 KW. I am not sure if that is a spike load or continues load for defrost and emergency heat. Looks like I should have done more research and purchased a larger generator.

 

[jimbo913]

The 9.6kw would be resitive load for the inside emergency heat strip. The generator would power it and provide another 5k watts max. I think they load bank right around 12kw at 100% and 15kw at 125%.
I ran 4AWG from my generator to the distribution panel.

 

[DieselAddict]

Its common to install a defrost/emergency heat bypass relay for when you are on generator power. That relay will block the signal to the contactor coil that energizes the heat strips.

My HP has 2 sets of heat strips. One set is used for emergency heat and one set is used for defrost. They are split across 2 sets of breakers )one 50a, one 60a). The 60a breaker powers the fan. On that circuit I disconnected the coil lead for the heat strips. That leaves the other set for use for defrost/emergency. I did a minor modification which merged those two signals so either mode (defrost or emergency) pull in the one set of heat strips. So for me when I don't want the heat strips to run I simply turn off the breaker for that circuit.

I leave the breaker off unless I know I'm going to need AUX heat. The balance point on my HP is around 10 degrees due to the amount of insulation I have in the house.

 

[jimbo913]

I would also turn off the outside units, but I dont really worry about it because my emergency heat is a wood fueled stove which draws <200w. My first backup to that is propane and third is the heatpump.

 

[Another Ahab]

I would also turn off the outside units, but I dont really worry about it because my emergency heat is a wood fueled stove which draws <200w. My first backup to that is propane and third is the heatpump.

Is the power to the stove just for a blower?

What is the electric element to your wood-fueled stove?