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Posted

Well, this is a first for me: I'm looking at two, side by side, Siemens 200 AMP breaker panels in the garage. There is no main breaker in either panel.

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Behind these panels on the outside wall are two side by side Automatic Transfer Switch Boxes.

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Yet, there is no generator or apparent hookup for a future generator. There isn't even the slightest indication there ever was a generator.

Each of the transfer switch boxes had covers hinged at the top and secured at the bottom with thumb-screws that were rusted fast to the box. I suppose they could have lifted up to reveal a generator plug in each box, but I've never seen a transfer switch built in to the hookup.

The panels are setup to be subs, with segregated neutals and grounds.

Even if the Transfer switch boxes to have plugs, what about main disconnects?

I'm stumped. Any insights?

Posted

OK, pictures and additional notes have been added to the original post.

Class is in session...

I can only guess that had I been able to get one of the covers up, I'd have found a generator hook up. But, that means that every circuit in this entire 6400 square foot home is generator ready.

Posted

It looks like they are "Generac 200 Amp Outdoor Automatic Transfer Switch w/ Service Entrance". See http://www.everygenerator.com/Generac-R ... N1030.html .

I can't find a photo of the interior, but my guess is that the "w /Service Entrance" bit means that there is a service disconnect under that cover. I think the generator (it would be a big one) would be hard wired from a remote location (was there a pit somewhere?). In other words I doubt that there will be a socket under the cover.

I'd call out the rusted screws as a safety issue and suggest the client gets more info on the set-up from the seller and/or a sparky.

Posted

I'm guessing that the enclosure in the 2nd photo which is situated to the left of the transfer switches has the main disconnect or disconnects within it. That would explain the separated neutral/grounds in the panelboards. I'm also guessing that this installation is meant to rely on portable generators which are wheeled up to the transfer switches in times of need. Any size power plant up to the transfer switch rating could be attached. Loads which are too large for the generator capacity to serve are switched off at the panel breakers. As for why 2 transfer switches are present instead of one, it's easier to get more power plant capacity to the site if you can accomodate two units. The presence of two panels makes that easily done. You could also hook up a single power plant to both transfer switches simultaneously if you wished, as long as you adjusted the connected load to match the KW and KVA capacity of the plant.

Marc

Posted

Marc, the edge of the box that is immediately to the left of the two transfer switches is the meter base.

Any way I look at it, there's no single throw disconnects for the two sub-panels. It's screwy.

I'll be checking out your links shortly Richard.

Posted

I'm not saying it's the correct move, but I definitely would have tried to pull the screws out of the transfer boxes so I could take a peek inside.

Posted

Yeah, Bain, at the time, it didn't enter my mind I would see much mor than wire connections, if I had, so when the thumbscrews woulddn't turn I didn't press the issue. Plus they weren't very hefty screws so I thought it easy to accidentally snap on off.

Now on the way home, I realized that what I didn't do and should have is look up under the covers and see if the bottom of the box was cut out to accomodate a generator cord with the cover closed. Too late now, but I surely should have done that.

I've never seen an entire home generator ready. Usually it's a sub panel with selected circuits.

Posted

In all my experiences in hurricane country, I've never seen an all electric single family dwelling with sufficient standby generator capacity to cover all loads. Last one I inspected was a 4 banger, propane powered stationary unit. It doesn't make much sense anyway. My own diesel portable is a 4 KW and that keeps my home reasonably cool in August via an 18,000 btu/hr window unit, that's with all light fixtures and general purpose outlets operational. That's all I need. An additional 4 KW, if I had the luxury of it, would give me hot water for showering and perhaps one element on the electric range.

Marc

Posted

Who's Tom? The generators in the 40KW to 60KW range that you would likely need to power the entire house, assuming the 400-amp service is justified, weigh in at 1300 -1500 lbs. Not exactly something you would wheel around and plug in.

I had something similar a few years back in a 7000+ sf hi-tech-everything home. The generator was in a large pit covered by metal grating.

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I swore off mega homes after that one. It was a confusing nightmare of multiple appliances and electronic systems.

Posted

It looks like they are "Generac 200 Amp Outdoor Automatic Transfer Switch w/ Service Entrance". See http://www.everygenerator.com/Generac-R ... N1030.html .

I can't find a photo of the interior, but my guess is that the "w /Service Entrance" bit means that there is a service disconnect under that cover. I think the generator (it would be a big one) would be hard wired from a remote location (was there a pit somewhere?). In other words I doubt that there will be a socket under the cover.

I'd call out the rusted screws as a safety issue and suggest the client gets more info on the set-up from the seller and/or a sparky.

That certainly seems to be the beast.

Posted

In all my experiences in hurricane country, I've never seen an all electric single family dwelling with sufficient standby generator capacity to cover all loads. Last one I inspected was a 4 banger, propane powered stationary unit. It doesn't make much sense anyway. My own diesel portable is a 4 KW and that keeps my home reasonably cool in August via an 18,000 btu/hr window unit, that's with all light fixtures and general purpose outlets operational. That's all I need. An additional 4 KW, if I had the luxury of it, would give me hot water for showering and perhaps one element on the electric range.

Marc

String drift. Forgive me, Mike, but I have a question for Marc.

We had an ice storm two years ago, and lots of folks were without power for a week or so. I connected a couple of gas furnaces to generators for friends, but the furnaces wouldn't work UNTIL I bonded their electrical-circuit ground wires to copper water pipes, which I wouldn't have known I needed to do without researching the internet. My question is, how do the furnaces' circuit boards sense that the electrical circuit isn't grounded and then prevent the furnaces from firing?

Posted

A bit more for you to peruse...

If you go to http://www.generac.com/Service/ManualSearch/ and enter RTSE200A3CSA in the search box, it will take you to a pdf manual. There are some photos of what is behind the front cover. It seems there is a "Utility Service Disconnect" there...and no socket.

Richard, in keeping with the manuals:

Thanks a lot. That was very helpful.

Muchos gracias, Eso era provechoso.

The bottom line for me is 1. they need to find out from the seller, who is also the home builder, what they've got here and more importantly, in an emergency, how do you shut it down in a coule of throws?

Posted

John, That was a smart move to try grounding the board. A lot of HVAC guys would've missed that. It was likely an issue with certain of the electronic components on the board, not a feature that senses something askew. MOSFET devices are charge driven devices and they are a big reason why the marriage of electronics and electrical power circuits has often been a rocky road. Heat, vibration, errant magnetic fields and RFI are often created by electrical power generators or loads yet are not tolerated well by most electronic components. I suspect that if the generator chassis had been grounded to the same ground rod which served the dwelling, the issue may not have occurred in the first place. Manufacturers of portable generators always recommend this in the manual but most people, including myself, don't bother with it. Generators often come with a chassis mounted lug for this purpose.

Just my opinion.

Marc

EDIT: Clarification

Posted

That was a smart move to try grounding the board. It was likely an electronics issue, rooted in the sensitivities of the electronic devices on the circuit boards. Perhaps some static charge was imparted to the electrical installation by the generator chassis. The marriage of electronics devices and electrical power circuits has often been a rocky road. I suspect that if the generator chassis had been grounded to the same ground rod which served the dwelling, the issue may not have occurred in the first place. Manufacturers of portable generators always recommend this in the manual but most people, including myself, don't bother with it. Generators often come with a chassis mounted lug for this purpose.

Just my opinion.

Marc

Those, definitely, aren't situations that lend themselves to textbook installations. It was something like 15 degrees outside, and my fingers stopped functioning after about ten minutes of exposure. One thing I did learn is that the generator needs to be at least twenty feet away from the house or the exhaust fumes seep in around the windows. Once I fired up the generator, I got a reading of about 30 ppm of CO with a Monoxor II.

Posted

I think someone wanted to have an option to add a generator at some later date, and used these ATSs as service disconnects. Considering the difficulty in removing the covers, it seems like a very bad idea.

There would need to be two generators with this setup. You can't have more than one ATS on each generator. Each ATS includes sensing circuits that periodically start the generator. In a utility outage, the ATS waits for the utility to prove power before transferring back from the generators to the utility. You can't have two sets of controls doing those things to one generator.

Having two generators is also a bad idea. If there is any cross-connection - even of the neutrals - between those panels supplied by separate generators, you can end up with some bizarre voltages and frequencies that will damage consumer electronic equipment.

A much better setup would have been to install a 4-pole transfer switch. Then it could be done with a single generator. 4-pole transfer switches are normally for 3-phase systems where the neutral is also switched, but they work fine in this application, with 2 pairs of hot conductors and the neutral not switched.

Richards links to the installation manual are very helpful.

It's too bad you weren't able to open these up. I wouldn't be entirely confident that all the parts shown in the manuals are actually there until I saw them.

I would have some concerns about the grounding of the ATSs. It is OK to have the grounding electrode conductor originate at the meter, upstream of these things, but I would try to find it. Next, the manual states that these things meet CSA requirements as "suitable for use as service equipment." To be approved for use in the U.S., they should be marked "suitable as service equipment" somewhere inside.

If they are going to install a generator, they should replace these ATSs with a 4-pole type. If they aren't going to install a generator, they should ditch these ATSs and replace them with a service enclosure that is easily operable.

Douglas Hansen

Posted

I think someone wanted to have an option to add a generator at some later date, and used these ATSs as service disconnects. Considering the difficulty in removing the covers, it seems like a very bad idea.

There would need to be two generators with this setup. You can't have more than one ATS on each generator. Each ATS includes sensing circuits that periodically start the generator. In a utility outage, the ATS waits for the utility to prove power before transferring back from the generators to the utility. You can't have two sets of controls doing those things to one generator.

Having two generators is also a bad idea. If there is any cross-connection - even of the neutrals - between those panels supplied by separate generators, you can end up with some bizarre voltages and frequencies that will damage consumer electronic equipment.

A much better setup would have been to install a 4-pole transfer switch. Then it could be done with a single generator. 4-pole transfer switches are normally for 3-phase systems where the neutral is also switched, but they work fine in this application, with 2 pairs of hot conductors and the neutral not switched.

Richards links to the installation manual are very helpful.

It's too bad you weren't able to open these up. I wouldn't be entirely confident that all the parts shown in the manuals are actually there until I saw them.

I would have some concerns about the grounding of the ATSs. It is OK to have the grounding electrode conductor originate at the meter, upstream of these things, but I would try to find it. Next, the manual states that these things meet CSA requirements as "suitable for use as service equipment." To be approved for use in the U.S., they should be marked "suitable as service equipment" somewhere inside.

If they are going to install a generator, they should replace these ATSs with a 4-pole type. If they aren't going to install a generator, they should ditch these ATSs and replace them with a service enclosure that is easily operable.

Douglas Hansen

Thank you Douglas. That was helpful. I haven't completed this report yet, and in light of all of the developing info and insights, I'm really tempted to go back out and get the ATs open. It's a vacant foreclosure, so it's not a problem. I believe I'll do that in the morning, so stay tuned and we'll see what gives.

Posted

I think someone wanted to have an option to add a generator at some later date, and used these ATSs as service disconnects. Considering the difficulty in removing the covers, it seems like a very bad idea.

There would need to be two generators with this setup. You can't have more than one ATS on each generator. Each ATS includes sensing circuits that periodically start the generator. In a utility outage, the ATS waits for the utility to prove power before transferring back from the generators to the utility. You can't have two sets of controls doing those things to one generator.

Having two generators is also a bad idea. If there is any cross-connection - even of the neutrals - between those panels supplied by separate generators, you can end up with some bizarre voltages and frequencies that will damage consumer electronic equipment.

A much better setup would have been to install a 4-pole transfer switch. Then it could be done with a single generator. 4-pole transfer switches are normally for 3-phase systems where the neutral is also switched, but they work fine in this application, with 2 pairs of hot conductors and the neutral not switched.

Richards links to the installation manual are very helpful.

It's too bad you weren't able to open these up. I wouldn't be entirely confident that all the parts shown in the manuals are actually there until I saw them.

I would have some concerns about the grounding of the ATSs. It is OK to have the grounding electrode conductor originate at the meter, upstream of these things, but I would try to find it. Next, the manual states that these things meet CSA requirements as "suitable for use as service equipment." To be approved for use in the U.S., they should be marked "suitable as service equipment" somewhere inside.

If they are going to install a generator, they should replace these ATSs with a 4-pole type. If they aren't going to install a generator, they should ditch these ATSs and replace them with a service enclosure that is easily operable.

Douglas Hansen

Thank you Douglas. That was helpful. I haven't completed this report yet, and in light of all of the developing info and insights, I'm really tempted to go back out and get the ATs open. It's a vacant foreclosure, so it's not a problem. I believe I'll do that in the morning, so stay tuned and we'll see what gives.

Pick up a little can of liquid wrench on the way.

ONE TEAM - ONE FIGHT!!!

Mike

Posted

Douglas,

Is it possible that one of the ATS's could be switched or modified to disable the generator test/start/stop functions, enabling the use of a single generator? The manual doesn't seem to suggest that but I suppose there could be different configurations or units under the covers. Not that I'm ever likely to see this particular set-up...just curious.

Posted

I made it out there and got the boxes opened.

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There are main disconnect switches inside each. They are identical. A toggle switch to turn off the AT feature is beside the main breaker.

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Here are the the most significant labels:

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I drove the perimeter of the property peering into the woods for any signs of a generator and scanned the outside of the home for any propane lines that might have been abandoned or roughed in for a generator, to no avail.

Posted

There is no generator. You would see the control wires and feeder conductors in your third picture, and they aren't there. Go back to the link Richard posted, and this time paste 0049451 into the search box. You will get a slightly different manual, one that matches this equipment exactly. I can't be sure from the photo, but it looks like the bonding jumper is missing at the neutral bus.

I suggest you call the Generac folks and ask them about this setup. It appears their equipment is suitable for use as service equipment. I would be curious what they have to say about installing two of them on one generator.

In a typical generator setup, the person who first turns it on is the installer of the transfer switch or a factory rep. The more complicated ones will have a lot of dip switches that must be set, and they want to program the timer for periodic startup and run it through its other tests.

One last note - even for large houses like this, a typical generator setup will be no more than 100 amps, if that. You don't expect to be able to operate everything; you do expect seamless transfer of power.

Douglas Hansen

Posted

Thanks again, Douglas.

I've seen a ton of generator panels and about 40% of the time they're done badly. But, I've never seen anything like this.

I've sent you the third photo so you can zoom in to confirm your suspicion that the bonding jumper is missing.

Kindly let me know here what you conclude.

Thanks in advance for your assistance.

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