phabib
I got this transfer switch with a Dayton brand and I'm planning to use it with my 13kw Generac. Can someone tell me what Generac switch I've got? Based on the age of the generator this switch was hooked up to, I'm guessing its from the mid '80's.

The connections are named alike, N1/N2, L1/L2, and 194/23.

When I flip it using the bar on the side it moves the connection between one of the two ends to the center and the indicator window red/green switches places.

From my checking continuity between a few points, I think the generator goes to the bottom 2 lugs, the house in the center and the utility should go to the upper 2 lugs. Is that correct? It would make me feel better to get confirmation before I test it using the smoke method.

Also, are the L1/L2 on the small screw terminals required, or are they just used for running some indicator that the generator is supplying power, or for some other reason?



Here is a link to the photo of the switch in question: [url]http://www.flickr.com/photos/phabib/5621094154/sizes/m/in/photostream/[/url]
Thank you
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Skip Douglas SkipD
Do you have a schematic diagram for the transfer switch and an installation document with schematic for the generator?

What model generator are you using?

What brand/model transfer switch are you attempting to use? Can you provide a high resolution photograph of the WHOLE transfer switch?

What's your background in electrical work?

Do you have a full understanding of the appropriate electrical codes?

There's a very real possibility that the transfer switch you have may not be appropriate for your application, as the transfer switch appears that it may be designed for a "whole house" backup application and your generator is probably not sized appropriately for that sort of service based on current electrical codes. It might help if you describe the overall scenario of how you intend to use the generator.
Skip Douglas
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phabib
Thank you for taking the time to answer. I'll do my best to respond to all of the questions you raised.

Since I'm not sure what Generac model switch this Dayton branded one matches up to, I don't have the switch's schematic. By knowing what Generac model this is, I hope to get it.

I'm not able to provide more photos right now since this is at a second home where I'm not.

In terms of background, I've built two house an did all of the electrical including bringing in service from the pole for both. I'm an engineer and I work with electrical devices so my understanding is good.

I'm probably weakest on code related stuff. I've talked to my inspector and looked here and other places for information.

I'm aware of the sizing but I'm not worried about it. This is a new house with extremely light electrical use. The combined use of every light in the house is about 1kW, all appliances are gas, there is no AC. If required, I will run the 30 day test for sizing.
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Skip Douglas SkipD
phabib;8816 wrote:
Since I'm not sure what Generac model switch this Dayton branded one matches up to, I don't have the switch's schematic. By knowing what Generac model this is, I hope to get it.
I'm not a Generac tech, though I installed mine back in 2008 with the aid of a hired electrician and my background in industrial control systems makes it easy for me to understand and troubleshoot mine.

My transfer switch, by the way, is a service-disconnect type, meaning that the utility service is wired from the meter directly to the transfer switch's 200A utility disconnect breaker. There is a similar 200A disconnect breaker for the generator feed. There are no branch circuit breakers in my transfer switch as the transfer switch powers the whole breaker panel for the house.

I have not dealt with transfer switches built back in the 1980s but I'd bet that several of the folks here have and they may recognize yours from the photographs.

The N1/N2 wires are typically connected to utility power 240 VAC in the transfer switch and each of the two lines is typically fused at 5A in the transfer switch. The N1/N2 circuit tells the controller in the generator that utility power is present. Different generators use the N1/N2 differently, so I cannot explain how your generator might be set up.

The typical generator/transfer switch that I've seen info on uses the 194/23 circuit from the generator's controller to activate a relay in the transfer switch which has a 12V coil when the generator wants to power the backed-up circuits. The 194 circuit is typically held at +12 VDC constantly and the 23 circuit is pulled to ground by the generator's controller to activate the relay. What the contacts in the relay do varies with the transfer switch design.

I don't see an L1/L2 in my more modern system so I won't even guess as to how those wires are used.

My transfer switch has the utility input labelled N1/N2. The generator input to the switch is labelled E1/E2. The output of the switch is labelled T1/T2. Neutral is common to both inputs and is, of course, wired to the load panel.
Skip Douglas
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bronco
You are correct on the placement of the utility, load and generator wire's. if you unit is a new one with the Nexus panel then you would use L1 for the battery charger that is labled T1 in the generator, if you don't have a T1 in the gernerator then L1-L2 are not used. If you give me the dayton number I can look it up. Tha bad about your switch is if the contactor goes bad you can't get a new one it has been out of production for some time.
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phabib
Thank you for the confirmation about the wire placement and the offer to look up the Dayton numbers. I was hoping they'd be visible in the photo, but it looks like the last digit or two is obscured.

I'll take you up on the offer to look up the Dayton number in a couple of weeks when I get back to the house and can read it.

I hope I don't have to swap out the switch for a long time to come. So few companies really keep making stuff forever and I know it doesn't happen at the lower end of the market where Generac lives.

In the computer biz, I've often had to explain to clients that they need to spend twice what a complete computer costs on just the board and that what they're getting for their money is the commitment to keep making it for several years and to pre-announce its being discontinued by at least a couple of years so they can plan accordingly.
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phabib
Bronco, I got some numbers off the transfer switch. If you're able to look up the Dayton number that would be great.

There is a paper sticker that says 93Y1082 I suspect this is a date or manufacturing code.

Then are also a couple of proper plastic labels. The first says

Dayton Transfer Switch
Part #62677
Rated Voltage 250VAC
Rated Current 200Amp

There is one that describes the coil
Coil 230V
MAC-DT

Then this one says what its supposed to work with:

Ass'y 89736
This transfer switch is for use with control module assembly #79844 - #75595 and 83494

Thank you for your help.
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bronco
Ok those numbers are not the model number the 62677 is the contactor the others mean nothing toward looking it up. The dayton model number will look something like this 4w117or 4lm*** it will have letters in it.
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phabib
I don't have anything that looks like that on this switch. I suspect the label with that number on it did not last until I got the switch.

Thank you for taking the time to look up this stuff.

I'll make the connections and hope that only modest amounts of smoke are released.
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