Announcement Announcement Module
Collapse
No announcement yet.
about to purchase a 20kw generator, it has 2 100amp transfer switches?? Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • about to purchase a 20kw generator, it has 2 100amp transfer switches??

    The genset is a Generac 20KW NG, residential, water-cooled, 4 cyl Mitsubishi. The seller is a contractor who removed the generator and the switch gear from a house he demolished.
    He says the house had 200amp service (as do I) he sent me pics of the genset and the transfer switches. Both TF switches are 100amp Generac model 71340. I was expecting a single 200amp switch.
    I'm having a hard time understanding how these 2 switches could have been wired in.
    I'm a mechanical engineer, I have a buddy who is an EE and a licensed electrician, but he's jammed up with storm damage stuff (he works for our local utility here in NJ).
    I need to make a decision on this unit since the owner has other interested people.
    Can anyone here shed some light on this for me?

    Thanks

    PS this was my first post on this forum, sorry it was so long

  • #2
    Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

    unless you split up the loads into two 100 amp boxes, I do not see how it would work (code wise) either,

    I found a manual 250 amp transfer switch off of Ebay a number of years ago, for my place,

    I do have a second transfer switch in the generator shed, to choose between a 30kw generator or a old small unit, that is plugged in to a receptacle, so if really needed I could park the welding truck and plug the welder (it also generators AC) in to the receptacle if needed as well and switch it on the second transfer switch,

    but for a whole house the transfer switch needs to amp rateing, the same as the power coming into the building so if you have a 200 amp breaker box, you would need a 200 amp transfer switch.

    Unless your putting some on a emergency panel, like some of the small transfer switch's do by powering 6 or 8 breakers,
    Push sticks/blocks Save Fingers
    ~~~~~~~~~~~~~~~~~~~
    "The true measure of a man is how he treats someone who can do him absolutely no good."
    attributed to Samuel Johnson
    ~~~~~~~~~~~~~~~~~~~
    PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.

    Comment


    • #3
      Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

      The only way they could have made it work was with 100A sub-panels. If you have a typical 200A service you'll need a 200A transfer switch. If the gen price is right a 200A Generac switch is likely only about another $800.

      Comment


      • #4
        Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

        this is a manual transer switch, not an automatic, but good price

        200 Amp New Single Phase Transfer Switch Stocklouisiana | eBay

        I personaly would not want an automatic unit, as running a generator is not cheap, unless you have a need for 24/7 power in an emergency, a manual works jsut fine,
        Last edited by BHD; 11-03-2012, 08:45 PM.
        Push sticks/blocks Save Fingers
        ~~~~~~~~~~~~~~~~~~~
        "The true measure of a man is how he treats someone who can do him absolutely no good."
        attributed to Samuel Johnson
        ~~~~~~~~~~~~~~~~~~~
        PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.

        Comment


        • #5
          Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

          i have a 16 kw onan trailer unit both 3 phase and single. i have a series of outlets and breakers. all is run off of heavy duty cord sets. then a big 50 amp spider construction box. keeps it simple and no rewiring. just plug and play for portability.

          good luck with your power. but don't jump the gun on the generator as everyone is looking to buy and sell right now.

          rick.
          phoebe it is

          Comment


          • #6
            Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

            Originally posted by BHD View Post

            I personaly would not want an automatic unit, as running a generator is not cheap, unless you have a need for 24/7 power in an emergency, a manual works jsut fine,
            We are Americans. We want EASY, convenient, FAST, and most of all........CHEAP!

            Comment


            • #7
              Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

              I'm looking now for a 200amp (+) transfer switch, but my time is limited by how long the seller will wait for me to decide.
              Another poster suggested a manual switch, which I had considered previously. At $375, it won't break the bank, while I look around.
              I have a 200amp main disconnect, just on-ff, between the meter and my panel, because my EE friend suggested it. I don't think that'll be a problem.

              Thanks for the great advice.

              Comment


              • #8
                Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                IMO for a few hundred difference you'd be crazy not to go with the PROPER automatic switch.

                Comment


                • #9
                  Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                  feed that generator for 30 days and your desire for 24/7 power will be diminished, you will start to think that a few Hrs a day to recharge the freezer and reefer will be just fine and to pump some water if you have a well,

                  most small generators only get about 1 to 2 hr per gallon and if loaded heavily the fuel use rises, and that one may take about 3 to 4 gallons and HR to operate,
                  http://www.generac.com/PublicPDFs/E1151.pdf
                  20 kW Models
                  Using Natural Gas ........................................359 cu. ft. per hour
                  Using LP Gas ............................143 cubic ft. (4.0 gal.) per hour
                  most likely it is on NG,
                  but still translate it to $3.00 a gallon, that is $9 to $12 and hr for operation of the unit, even $2 dollar a gallon fuel @ 4 gallons an hr, is $8 and hr fuel cost for operation of the unit,

                  go with what ever switch you want, It does not bother me any but if you have a 30 day power outage,
                  you be glad you have the generator but you won't like the bill, and most likely you will figure out how to run as little as possible,
                  with electric start on the generator it is no harder than starting a car, and once started, walk over and flip the transfer switch, and reverse when shutting it down,
                  Push sticks/blocks Save Fingers
                  ~~~~~~~~~~~~~~~~~~~
                  "The true measure of a man is how he treats someone who can do him absolutely no good."
                  attributed to Samuel Johnson
                  ~~~~~~~~~~~~~~~~~~~
                  PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.

                  Comment


                  • #10
                    Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                    Originally posted by BHD View Post
                    feed that generator for 30 days and your desire for 24/7 power will be diminished,
                    ........
                    go with what ever switch you want, It does not bother me any but if you have a 30 day power outage,
                    you be glad you have the generator but you won't like the bill, and most likely you will figure out how to run as little as possible,
                    30 days??? Seriously? When was the last 15 day outage, let alone 30 days, that you've heard of??? At least in a non-remote location.
                    The OP is in New Jersey. I bet 90 of the folks out don't break 10 days. And by this I mean the folks without very serious damage.

                    Comment


                    • #11
                      Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                      In our area there has been a number of 30 day outages, our farm has had a 30+ day outage, not really that uncommon here, when 100's of miles of line go down with the poles, we do not get the press because of the sparse population, but when it happens have fun, (some ice storm in the spring will tear things up from time to time),

                      granted there not that reoccurring, but do happen, yes most of our outages are in hours not days,or weeks, but you do not need a generator for power outages in hours, (normally), and even a few days one should be able to get buy with out much problem, the generators are nice tho in a few day outage, but when your with out for a three or more days the generators can be very helpful,

                      I apologize if my posts are colored by my experiences and area of life, (he asked question) and I gave him the answer and the why of my answer from my experience, If he is only dealing with a few hr, outages, go get a portable generator, and some extension cords, and get a tri fuel kit for it, so it will run on NG, or propane, (normally easer than storing gasoline), if he was a farmer I would not suggest a generator but a gas powered welder with generating capacities, (much more versatile machine) more use for it. day to day,
                      Last edited by BHD; 11-04-2012, 11:24 AM.
                      Push sticks/blocks Save Fingers
                      ~~~~~~~~~~~~~~~~~~~
                      "The true measure of a man is how he treats someone who can do him absolutely no good."
                      attributed to Samuel Johnson
                      ~~~~~~~~~~~~~~~~~~~
                      PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.

                      Comment


                      • #12
                        Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                        Originally posted by BHD View Post
                        In our area there has been a number of 30 day outages, our farm has had a 30+ day outage, not really that uncommon here,
                        That's kind of my point. You cannot compare NJ to the location written in your profile.

                        Comment


                        • #13
                          Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                          Just so you know, If an automatic transfer is used to supply the whole house, a load calculation needs to be done. The generator and service eq. must be large enough to serve the entire load served. Not necessary for a manual transfer but it must be large enough for the load served.

                          I would not just guess, figure out the actual calculated load. You might save thousands after finding out you only need a 12k gen set.

                          Comment


                          • #14
                            Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                            unless you have life support needs, or a store of freezers. a manual transfer switch is really a better choice. less complicated and turn it on when needed, exercise when needed and keep it simple.

                            rick.
                            phoebe it is

                            Comment


                            • #15
                              Re: about to purchase a 20kw generator, it has 2 100amp transfer switches??

                              Originally posted by johncameron View Post
                              Just so you know, If an automatic transfer is used to supply the whole house, a load calculation needs to be done. The generator and service eq. must be large enough to serve the entire load served. Not necessary for a manual transfer but it must be large enough for the load served.

                              I would not just guess, figure out the actual calculated load. You might save thousands after finding out you only need a 12k gen set.
                              Or have load shedding ability.

                              A 20kW would typically be fine for a typical small home.

                              Comment

                              Working...
                              X