Generator Transfer switch connection choices

[daybreak1998]

FYI, I asked both NYSEG and RG&E about this via their websites and I just heard back from NYSEG. Here is what they had to say:


Still waiting to hear back from RG&E (who actually owns the meter).

Aaron Z

Howdy,
I am only talking about the style of meter base. My local utility uses horn style ringless. There are many variations of the meter bases. Yes, UL approved, but you need to use the style and type that works with your utility. Yes, the utility will not move forward until the inspection is OK'd.

 

[aczlan]

Howdy,
I am only talking about the style of meter base. My local utility uses horn style ringless. There are many variations of the meter bases. Yes, UL approved, but you need to use the style and type that works with your utility. Yes, the utility will not move forward until the inspection is OK'd.

Good point. RG&E requires the same. Looks like GE 200 Amp 4-Space 8-Circuit Outdoor Combination Main Breaker/Ringless Meter Socket Load Center TSMR420CSCU at The Home Depot is the one that I would need (TSMR420CSCU). $108ish locally and takes the same interlock.

Aaron Z

 

[MNBobcat]

Howdy,
"The interlock"

The interlock makes it so only 1 breaker can be on. The main panel breaker, or the generator breaker. So, you turn off the main 200amp breaker, slide the metal interlock, and now you can turn on the generator breaker.
View attachment 272502 click on the picture to see larger, then click again to zoom in.


Your panel needs to have a interlock kit for it. It usually needs the 2 top right spaces for the generator breakers. If your panel is full, a lot of times you can get half breakers to help make some room.

I like this option a lot because I'm not spending a lot of money on a temporary transfer switch that would be unneeded some day when I get a generator big enough for the whole house. My thought was use one of these and then flip off all of the breakers I don't want to power before I start the generator. The one problem with this plan is this approach doesn't provide a meter that shows how much load I'm putting on the generator. Is there a way to put a meter on the panel that would be active when the the interlock is flipped and the generator in use?

 

[aczlan]

Is there a way to put a meter on the panel that would be active when the the interlock is flipped and the generator in use?

I am looking at getting something like this: Gen/Tran Remote Metering Kit RMK-15-I RMK-15-F RMK-15-O and mounting it by the inside panel where I can watch the current usage and balance usage between the legs ahead of time.

Aaron Z

 

[daybreak1998]

Howdy,
The interlock kit does not have a certain amperage limit. The limit will be the size of dual pole circuit breaker you can find to fit your panel. Most folks use a dual pole 30amp breaker.

 

[daybreak1998]

Howdy,
You can post questions here. That way everyone learns something... I don't mind the PM's, but the questions might be something someone else is thinking too.

Your service entrance load panel.
Not all load panels have interlock kits for them.

You can browse through these vendors (I have never used them, I do not know if they are any good, but the web site shows all the ones which they have interlock kits for)

National Ram Electronics
and / or
GenInterlock

The dual pole breaker for your generator hook-up can be any size. Standard dual 30amp for 8000w generators or dual 50amp for 10,000w generators, up to whatever size you can find and fit in your panel.

 

[daybreak1998]

Howdy,
Yes, I use the Tiger Power PTO generator 30kw to run the central farm distribution. The connection is with 350amp Anderson ends with 2/0 welding wire. The wire and connections can handle a lot more than what my 30kw puts out. The connection is called a full power plug. The transfer switch can handle 40kw continuous and 48kw peak.

Tiger Power 30kw PTO generator
30,000 prime duty running watts, 90,000 surge starting watts
here is a quick clip running drawing 18.0kw and then dropping to 15.4kw
[video]https://www.dropbox.com/s/d2g0zdbjdi83rd6/generator%20running.mp4[/video]

 

[daybreak1998]

Howdy,

PSP Products makes a few different sized items. I do not know if they are approved in your neck of the woods with your Utility. You would have to check with them. You would then need to talk with PSP Products about what equipment would work for you.

PSP Products Transconnect switch gear from this page you can see they offer a few styles.

good luck.

 

[bjmsam]

As mentioned here, I have a 400 amp service that feeds two 200 amp main panels.

I bought a TED 5002 to monitor my energy usage and confirmed that a 15KW PTO generator would suffice.

I bought two Square D QOCGK2C interlock kits and two 50 amp double-pole breakers to occupy spaces 2 and 4 of each panel:

I bought a Reliance Controls MB125 50 amp meter box to monitor load balance.

I bought a GE 50 Amp Twist Lock Power Inlet with L14-50 connector (larger and more robust than the popular Reliance Controls PB50).

I bought 3/4 in. Flex Aluminum Conduit and 8 gauge THHN wire (rated for 50 amps and much easier to work with than Romex 6/3 with ground).

I bought a Conntek 1450SS2-15 Temporary Power Cord with NEMA 14-50P Generator Plug to CS6364 Locking Connector.

Now I am trying to wrap my head around the parallel neutral path that this approach would introduce as discussed at length in this thread. The neutrals are presumably bonded at the meter and to ground at the disconnects between the meter and each panel. I don't yet understand 1) why a secondary neutral is unsafe if it's of the same gauge as the primary, or 2) why it would be unsafe to connect the generator neutral to only one panel to leverage the existing primary neutral connection to the other panel. Worst case I can order another inlet box and associated wiring to connect each panel separately, in which case the parallel neutral path would exist only when the generator is connected via a Y cable. Thoughts?





(edited to update broken links for reference)

 

[daybreak1998]

Now I am trying to wrap my head around the parallel neutral path that this approach would introduce as discussed at length in this thread. The neutrals are presumably bonded at the meter and to ground at the disconnects between the meter and each panel. I don't yet understand 1) why a secondary neutral is unsafe if it's of the same gauge as the primary, or 2) why it would be unsafe to connect the generator neutral to only one panel to leverage the existing primary neutral connection to the other panel. Worst case I can order another inlet box and associated wiring to connect each panel separately, in which case the parallel neutral path would exist only when the generator is connected via a Y cable. Thoughts?

Howdy,
I see you have been busy. I see exactly what you want to do. But, I am not sure it can be accomplished. That is also one of the reason I have the Transconnect unit. In my meter box, I use the feed thru lugs to feed 2 200amp panels, a 60amp well panel, a 100amp shop panel, and a 100amp barn panel. Being a central farm distribution, I can power whatever is needed when on generator power.

Because of the complexity of what you want to do. IMHO you should maybe get a local PRO in your area. I do not think you will get the best internet advice to be able to do it correctly and safely.

 

[bjmsam]

I see exactly what you want to do. But, I am not sure it can be accomplished. That is also one of the reason I have the Transconnect unit. In my meter box, I use the feed thru lugs to feed 2 200amp panels, a 60amp well panel, a 100amp shop panel, and a 100amp barn panel. Being a central farm distribution, I can power whatever is needed when on generator power.

I would really like to go that route, but at $4,333, the TC2OSM2LO is simply not an option.

 

[DJ54]

Here, they wouldn't let me use the two, 200 amp main panels for a disconnect. Had to be a manual, knife type. Absolutely no breakers. Engineer told me current can jump across a breaker. I'm thinking more of a safety factor for lineman, in case someone doesn't kick the main panel, and back feeds out on the main line. With a manual throw disconnect, there is no way that can happen.

Had a lineman here 5-6 years ago get electrocuted, about 5 miles away because of someone doing that. It stopped his heart, but paramedics got him revived... Seems after that, they really started pushing the manual throw disconnect.

 

[bjmsam]

Here, they wouldn't let me use the two, 200 amp main panels for a disconnect. Had to be a manual, knife type. Absolutely no breakers. Engineer told me current can jump across a breaker. I'm thinking more of a safety factor for lineman, in case someone doesn't kick the main panel, and back feeds out on the main line. With a manual throw disconnect, there is no way that can happen.

An interlock kit ensures that only the 200 amp main breaker xor the 50 amp generator breaker can be switched on at any one time. With the 200 amp breaker switched on, no power from the generator hots can reach the panel. With the 50 amp breaker switched on, no power from the generator can reach the main line hots. Breakers do not switch the neutral, so perhaps that is what the engineer meant by "jump across a breaker," though 1) I don't see how the number of panels involved makes a difference, and 2) I don't see how this is a safety concern for lineman considering the neutral is grounded before it leaves the meter.

 

[daybreak1998]

I would really like to go that route, but at $4,333, the TC2OSM2LO is simply not an option.

Howdy,
You talked it over with PSP Products? Which model would work for you? Do you have that much draw that you have 400 amp service? or is it 200amp service using feed thru lugs. The picture of your meter showed it was a 200amp meter. I would think the model retro-fit meter collar style with a 50amp generator plug would work.

 

[bjmsam]

PSP never responded to my inquiry. A 200 amp meter is often used for a 400 amp (320 amp continuous) residential service such as mine.

I sure wish this thread did "rehash the neutral-ground issue."

 

[DJ54]

Not arguing the point on the interlock, just they wouldn't let me use the 2, 200 amp mains for a manual disconnect. What times we did need a generator, we'd just kick the main out on the main breaker box, and feed back through the welder plug in the shop. That's where the problem was, when people start their generator's, and forget to flip the main on the breaker box, doing like we did, feeding back out on the line.

I removed the one panel in the middle in the second pic, but left the other since it already had wire running to the house, waiting to be switched.

On the inside of the shop is the transfer switch. Picked up off of both sides of that switch in the trough over head. One going into the 200 amp. breaker box in the shop, and the other going out through the wall, into the 200 amp disconnect to the house.

There was some miscommunications between the electrical contractor, and the engineer as to a disconnect. So there shot about $600.00 for a box, & labor. Finished the rest myself changing it out & the manual transfer switch.

I did get flamed on here pretty good about using the sch. 40 "water pipe" instead of the electrical conduit. But, they didn't have the 22-1/2º angle fittings I needed to make the softer turns to make what I already had work, in conduit fittings. And not enough room to use the long sweep fittings. From what I gathered on a couple evenings of seeing the difference between the two, it seemed to come down to, color was the only difference, which started another argument... No problem, I can live with it. There are a few runs here that have been in ground, and above ground for over 30 years, and no deterioration so far.

If you note the safety light up on the pole. that was the engineer's idea. It is wired into the utility side, so as to let you know power has been restored, IF you happen to remember to flip the switch, when going to generator power.

 

[bjmsam]

...and there's the rub. Some aspects of the code (typically later revisions) tend to push sensible risk management (things that may not be ideal but that are not dangerous to someone following basic safety procedures) too far toward risk prevention (insurance for Darwin Award candidates), often rendering compliant implementation prohibitive, thus compelling the un[der]qualified to come up with workarounds that are often downright lethal ("suicide cables" for dryer plugs), which defeats the purpose of such regulations to begin with. The electrician I consulted claimed that an inspector would fail any installation that involved powering my panels with a 15KW PTO generator because "it isn't powerful enough to run all conceivable loads." My TED tells me exactly what my load is, and shedding is easy, so I am not inclined to sacrifice the flexibility I need and am instead doing my best to find a solution that is safe, if not to code.

 

[daybreak1998]

Howdy,
I am sorry you have completed so much work already with your service upgrade and stuff. Not to take it lightly, but if things do not work out, you could remove the meter socket and the 2 200amp disconnects. There are some products which would replace all of them in 1 product. I was looking at them before working it out with my utility for the Transconnect product I am using now.

The Durham Company. 400 amp Standby Generator Transfer Switch
It would hold your meter, it has your method of disconnect, and it has your generator connection, all in 1 product.

 

[bjmsam]

Thanks! That would have been a better option during the heavy-up. Live and learn?

I bought a second GE 50 Amp Twist Lock Power Inlet and a Coleman Cable 50 amp Y adapter to finish things off.

 

[daybreak1998]

Thanks! That would have been a better option during the heavy-up. Live and learn?

I bought a second GE 50 Amp Twist Lock Power Inlet and a Coleman Cable 50 amp Y adapter to finish things off.

Howdy,
OK, some time has passed. How does your whole system work? It is working the way you want?