Installing Furnace Transfer Switch

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  #1  
Old 01-28-11, 07:03 PM
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Installing Furnace Transfer Switch

Hi,
I purchased the below device based on feedback from this forum. I was so excited to find something that met my needs. Basically I wanted to be able to power my gas, forced air furnace with a gas generator during a power outage.

After reading the directions I noticed it directs me to connect this directly to my electrical subpanel, something I'm not comfortable doing.

I was expecting that I could just splice into the electrical wire going into the furnace, the one that powers the fan unit. Is that not right? or is it a code issue?

Here's the device:

Reliance Furnace Transfer Switch — Single Circuit | Transfer Switches | Northern Tool + Equipment

As always, thanks so much for everyone's help!
 
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  #2  
Old 01-28-11, 08:19 PM
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It appears to me that the furnace circuit is redirected to this transfer switch and connected to the line terminals and the load terminals are then wired directly into the furnace. The extension cord from the generator plugs into the power inlet on the transfer switch. This is a one circuit transfer switch, I wouldn' think you would want to try to power the whole panel with it, but I haven't seen the instructions.
 
  #3  
Old 01-28-11, 09:06 PM
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What size generator you have with ya ??

That single circuit manual transfer swtich you slap it on next to the breaker panel { either main or sub panel } and you only control one circuit noting else in that panel at all during generator mode.

If you have pretty good size generator you can able get 6 circuit verison and use the inlet box somewhere else and with 6 circuit verison that usally plenty to handle almost anything as long you are under 5,000 watts.

Keep in your mind some gaz furance with electroic circuit boards some may not take generator power due either too high a HZ or voltage too high or dirty power { that one of few items that some generators delovep the issue and make your furance not work on generator power } unless you have Honda or other type of Inverter generators that those unit is very clean power source but very limited with surge rating.

Merci,
Marc

Merci.
Marc
 
  #4  
Old 01-29-11, 06:36 AM
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Hi all, thanks for responding. I'm sorry, I definitely didnt explain my question clearly

First, to your question, I have an 11,000w generator (6k starting).

I dont want to have to connect the transfer switch to my circuit panel.

Instead id like to just install it directly to the furnace. There's a wire coming out of the furnace that runs all the way to my panel. i'd like to install this new box right next to the furnace and just "splice" into the wire that powers the furnace.

Does that sound right?
 
  #5  
Old 01-29-11, 07:55 AM
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You can mount the single circuit transfer switch anywhere along the routing of the circuit, at the furnace will work just fine. But, you don't just splice into the existing circuit. The existing circuit will have to be routed into the transfer switch and properly terminated on the line side lugs. Proper terminations are also required on the load side lugs to continue power on to the furnace.
 
  #6  
Old 01-29-11, 12:06 PM
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ok definitely. poor choice of a word :-) As long as I can connect the transfer switch directly to the furnace, w/out going through the main circuit panel I should be fine.
 
  #7  
Old 01-29-11, 12:30 PM
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I have to look it up but I dont think you can do that. That transfer switch is made to bypass the breaker. When I did mine it was something like removing a leg of the existing breaker and tie the tranfer switch breaker to that Hot and a transfer swtch common to the common rail and such with ground.

Plus thats a 15 amp. What size breaker is in your panal for the furnace? Plus that transfer switch cant handle the watts of your gen. There is a max limit.

11000 watt gen. Wow you can do alot with that.

This one handles the wattage you need. Is outdoors, and run it to the panal correctly.

CSR302 Easy/Tran | Product Details | Reliance Controls Corporation

But with your gen why not use it. Get this.

R30310B Pro/Tran | Product Details | Reliance Controls Corporation



Mike NJ
 
  #8  
Old 01-29-11, 02:01 PM
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Mike, you're obviously a fine plumber but you are not an electrician. The proposed transfer switch is just fine for the proposed application. It doesn't have to handle the entire output of the generator, only the load (furnace) to which it is connected.

Beheron, follow the instructions of CasualJoe and you will be fine.
 
  #9  
Old 01-29-11, 02:28 PM
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Yes I am not an electrician and am using knowledge from when I installed mine. I am just trying to bring up points that some may have overlooked

He said he has a 6000 watt gen and that switch is only rated at 2500 watts. No one has told him if he can or cannot install it for that reason alone.

And I think I was trying to explain what Joe was saying, I dont have the electric lingo down.

Just try'in to help

Mike NJ
 
  #10  
Old 01-29-11, 02:32 PM
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I know that you are trying to help and I commend that action.

Yes, he CAN install that particular transfer switch for his furnace regardless of the size of the generator. The transfer switch is going to only carry the current drawn by the furnace and that will almost certainly be less than the fifteen ampere rating of the switch. It is no different than using a fifteen ampere switch on a twenty ampere circuit breaker fed from utility power. It is the size of the load that determines the switch rating, not the size of the source.
 
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Old 01-29-11, 03:31 PM
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Crude..I better stick to %&$# flows down hill and water seeps its level. (Two things plumbers need to know) LOL...

Mike NJ
 
  #12  
Old 01-29-11, 09:18 PM
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Originally Posted by bheron View Post
Hi all, thanks for responding. I'm sorry, I definitely didnt explain my question clearly

First, to your question, I have an 11,000w generator (6k starting).

I dont want to have to connect the transfer switch to my circuit panel.

Instead id like to just install it directly to the furnace. There's a wire coming out of the furnace that runs all the way to my panel. i'd like to install this new box right next to the furnace and just "splice" into the wire that powers the furnace.

Does that sound right?
I just want to clear up one misunderstanding here the generators the starting or surge wattage is always higher than running wattage so if you have 6,000 watts running with 11,000 surge or 11,000 running watts with 16,000 surge wattage ?

Can you please clear up that details ??

If that is true with 11,000 watt { a very large portable generator unit } IMO I do not want to be harsh but sound like over kill for furance useage and you can have more circuit add to this generator.

I have quite few customers which they ran 9-11,000 watts generator for whole house due they only used selected circuit with transfer panel.

To run unloaded on the gaz generator ( 11,000 watt class ) they are not too bad but expect to burn about 3/4 to a gallon of fuel per hour but once loaded up to near limit it will raise up to pretty close to 3 gallons per hour. ( depending on what engine brand that will affect the fuel useage )

Merci.
Marc
 
  #13  
Old 01-31-11, 03:14 PM
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I have a 10kW generator that feeds a 10 circuit transfer switch. It serves the furnace, refrigerator, chest freezer, microwave, garage door opener, a few outlets, and all of the overhead lights/fans. I did oversize the generator a bit to make sure there wouldn't be any issues with my furnace when the refrigerator or freezer kick on and draw their startup surge. Marc is not kidding, when nearing full load the large generators drink a LOT of fuel. I converted my engine to run on natural gas, and it hooks up to the grill outlet with a quick-connect hose. That way it avoids many of the common issues you get with gasoline - fuel stagnation/sludging, rapid fuel consumption (no shutting down to refuel at 3am in the snow), and hard starting. Just keep in mind this is a permanent conversion (unless you use a dual-fuel kit), so you won't be able to use the generator as a portable anymore.

That being said, if the unit is really that large, then you will definitely want to use a 'whole house' transfer switch to your advantage. These do install at the main panel, but it is not anywhere as hard or scary as you think it is. You just have to respect the electricity that is inside the panel.
 
  #14  
Old 01-31-11, 06:06 PM
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He could Install the small transfer for his furnace and install a larger one down the road.
 
  #15  
Old 02-01-11, 04:11 AM
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Depending on the age of the furnace it may not run on generators that don't produce a true sine wave. If the furnace has digital electronics in it, test it with a temporary hookup before you permanently install the transfer switch.
 
  #16  
Old 02-01-11, 09:11 AM
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Wow, great feedback.

Ok, some more answers to your questions and some background.

First, I have a HomeWatt 6,000W generator. I believe it has a 11,000k surge. I copied this directly from the user's manual:

Rated Voltage .................................................... 120V/240V
Rated Amps ................................................................22.9A
Rated Output ..........................................................5,500 W
Maximum Output ...................................................6,000 W
Rated Frequency ........................................................60 Hz

Hopefully that gives you an idea of what I'm working with.

Now, a few more details:

- I do have this generator to power other devices in my home (fridge, fan, lights, etc)

- I do NOT have this connected to any sort of sub panel, transfer panel, etc. I would love to do that eventually.

- I also would like to power my gas, forced air furnace with this generator, so I purchased the Reliance Furnace Transfer Switch (link above)

I did some really crude sketches to show what I'm thinking:

First, the setup today:
- furnace is supplied with power from a 15a line from the main house panel
- there's a receptacle in line that has a single outlet controlled by a switch. this is currently used for a small pump that collects condensation from the A/C in the summer.
- I'm mentioning this b/c this is where I was thinking of "tapping" into the line



Now, for what I'd like to do:
- install the transfer switch near the switch/outlet receptacle
- take the line from the receptacle and use it for the "input" into the transfer switch
- take the line OUT of the transfer switch and back into the receptacle
- power the transfer switch from the Gen with a properly rated extension cord.





I'm am just a simple DYI'er so this is pretty crude. I know I have to go over the instructions again to make sure the switch can be wired this way. I'm using the receptacle box since its a place where the power line is already "cut into", for lack of a better word.

Let me know what you think!
 
  #17  
Old 02-01-11, 09:20 AM
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Your generator is rated for a continuous output of 5,500 watts with a momentary surge output of 6,000 watts.

Your proposed connection diagram is fine. Connect all the bare (equipment ground) wires together along with any green wires that may be present. Include a green bonding wire to the enclosure if it is metal. Connect all white wires together. You will have only black wires connected to the actual transfer switch. It is not necessary to "ground" the frame of the generator.
 
  #18  
Old 02-01-11, 09:35 AM
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Hi Furd, thank you for confirming all of this! Wow, I'm very excited. We've really been hit hard with storms last year and this year and I would love to tell the wife we'll be warm if we ever have an extended outage. I will post progress and pics on here when I finish...now that I have the confidence to "start" :-)
 
  #19  
Old 02-01-11, 09:51 AM
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You're welcome. Having twice endured three day outages in the last ten years I guaranteed no more by investing in a small generator and rewiring to a "standby" panel with transfer switch. I can run my refrigerator, furnace, microwave oven and computer or television (with DVD player) so I will be warm, fat and stupid. Of course since buying the generator three years ago and making the wiring changes I've only had one four hour outage.

During the last three-day outage the inside temperature dropped to about 43 degrees, I couldn't do anything but stay in bed with the blankets over my head. I hate urban camping.
 
  #20  
Old 02-01-11, 07:24 PM
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Good stuff! Someday I'd love to install a sub panel for this generator (and I'll surely come to this forum for guidance). Many of the houses in my neighborhood have those big time gens tied directly to the natural gas lines. Love 'em but couldnt stomach the $$$.

Oh, and same thing here. Since I purchased this sucker I've had one, a single outage. I cam home from work all proud to set it all up. Within 5 minutes of starting the gen and running all my fancy extension cords around the house, I plugged in one fan and the power was back.

Thanks again.
 
  #21  
Old 01-09-12, 07:35 AM
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So a year later....I'm finally getting to this project. I never got around to it over last winter and now, well, you know. Anyway, I attempted the above yesterday, with a simpler approach but ran into a problem and need some quick advice.

A recap, I purchased this product:



Link:
Reliance Furnace Transfer Switch Single Circuit | Transfer Switches | Northern Tool + Equipment

and am installing it "in-line" is what I call it. I spliced into the 15a conduit going from my circuit panel to the HVAC blower. Some quick sketches:




Then I spliced into the line and installed the transfer switch



The transfer switch has 4 wires:
  • Red
  • Black
  • White
  • Bare ground

And this is how I wired each:
  • Red - incoming HOT (from breaker panel)
  • Black - outgoing HOT (to blower)
  • White - to white
  • Bare ground - to ground

When I turned the breaker for this line back on from my main panel, it worked fine. The blower was running no problem.

However, when I tried to power it from my generator, not so good. The generator's breaker tripped immediately (I didnt even have a chance to flip the trasnfer's switch).

Here's what I did:
- Turned off the breaker on the main circuit panel (to simulate a power outage)
- started up my generator
- connected a 12amp rated extension cord to the 20a breaker on the generator
- connected the other end to the the transfer switch.

As soon as I did the last step, the generator trips its own breaker.

Thankfully my generator has a breaker b/c obviously I wired something wrong?
 
  #22  
Old 01-09-12, 07:52 AM
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Was that a GFCI breaker that tripped?
 
  #23  
Old 01-09-12, 07:56 AM
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Looks like its wired correctly.

http://www.reliancecontrols.com/Docu...structions.pdf

What generator is this again?

Does this gen have GFI's?

The gen may be the issue.

Mike NJ
 
  #24  
Old 01-09-12, 08:02 AM
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I didnt think about that. Now that you say it, it was a GFCI "like" popout button that tripped. SO it looks just like one of those GFCI outlets. But before I answer let me see if I can find out for sure.

Also, want to note that when I plugged in the ext core, the reliance transfer switch was still set on "LINE".

Be back in a few...
 
  #25  
Old 01-09-12, 08:07 AM
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Update on the above:

just checked and youre right. I plugged the extension cord into a "20 amp GFCI" receptacle on my generator.

So you think there's a surge or something? Maybe I should flip the switch to the GEN side beforehand?
 
  #26  
Old 01-09-12, 09:41 AM
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I would say you need to unbond the generator. You did not state the make and model.... The issue I believe is you have two bonded areas. The gen and at the transfer switch/panel.

Its easier probably to unbond the gen then get wire a switching nuetral at the transfer switch.

The problem is then if you use the gen for stand alone use you need to put it back and bond the nuetral.

This is a mis understood area about gens and bonding/grounding.

Do a search and you will find many articles regarding this.


Here is a good one.

http://159.105.83.167/Portals/0/WP S...tandards22.pdf


The electricians will clarify.

I know Furd knows this stuff well but I have not seen him post lately.

Miss that old guy......

Mike NJ
 
  #27  
Old 01-09-12, 10:00 AM
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Ok, very interesting. I'm a novice DIY'er so had no idea about this. I read the article which was actually a good read and able to follow (side note, I thought I needed to ground my generator with a grounding rod b/c the manual says to so. guess not after reading this).

Anyway, looks like it might just be easier to install this thing directly to the circuit panel like the instructions show. I've never done anything like that before, but the instructions look pretty straightforward. Should be something a novice DIY'er can do?
 
  #28  
Old 01-18-12, 03:30 PM
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Update

Ok, I've decided since it looks like I'll have to tap into the service panel to install a full blown, 10 circuit transfer switch. This will serve BOTH hvac systems as well as a few other things. I'll start a new thread and detail my project there. thanks everyone!
 
  #29  
Old 01-31-12, 03:13 PM
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Thanks to all who helped here. I've started a new thread to document the installation of a 10 circuit transfer switch here...

http://www.doityourself.com/forum/el...ml#post1935563
 
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