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Advice for hiring electrician to install manual transfer switch

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  • #16
    Originally posted by lkruper View Post
    He said that if the generator is bonded neutral GFCI that I would need a three pole transfer switch (eg XRC0603C) which evidently is a much bigger job to install that a pre-wired transfer switch. He described it as the same amount of work as installing a new panel.
    He is exactly right, if the Genny has a Bonded Neutral, it is SDS and requires 3-poles, exactly what I have told you. GFCI has nothing to do with it. Generator outputs are GFCI because the Generator cannot produce enough current to operate the main breaker fast enough, just like an Inverter cannot deliver enough current to operate a main and even some branch circuits. As a general rule it takes 6X current to operate a Fuse/Breaker quickly. Generators and Inverters cannot do that as they are soft sources.
    MSEE, PE

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    • #17
      Originally posted by lkruper View Post
      So now my question is: Are GFCI and bonded ground-neutral mutually inclusive?
      GFCI needs no ground and no they are mutually exclusive.
      MSEE, PE

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      • #18
        Originally posted by lkruper View Post
        His only concern was that the generator has so little power that he is concerned it will be overloaded... it is only 13.3 amps. He was also concerned that I find a transfer switch with 110v inputs and not 240v inputs.
        Yeah that is a concern. 13 amps? @ 120 VAC? That is only 1500 VA. That is not a generator, that is a toy with a Briggs and Straton 2.5 hp lawn mower engine.
        MSEE, PE

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        • #19
          Originally posted by Sunking View Post
          Yeah that is a concern. 13 amps? @ 120 VAC? That is only 1500 VA. That is not a generator, that is a toy with a Briggs and Straton 2.5 hp lawn mower engine.
          True, but I am running toys

          Watts @ 110v
          =========
          DSL Modem: 6w
          Direct TV Satellite Receiver : 19 w
          TV: 60w
          Small Desktop: 8w
          Laptop: 20w
          IPAD: 2-4 w
          Cell Extender: 14w
          Cameras: 18w
          Small Fridge: 28w
          Some Lights: (Have oil lamps and Coleman battery powered too)

          Hot Water Heater: 220v will not be powered.
          Oven: 220v will not be powered (Have propane burners and BBQ as well as Fireplace cookware)
          Microwave: 750w ... not sure... don't use much

          Comment


          • #20
            Originally posted by lkruper View Post
            True, but I am running toys

            Watts @ 110v
            =========
            DSL Modem: 6w
            Direct TV Satellite Receiver : 19 w
            TV: 60w
            Small Desktop: 8w
            Laptop: 20w
            IPAD: 2-4 w
            Cell Extender: 14w
            Cameras: 18w
            Small Fridge: 28w
            Some Lights: (Have oil lamps and Coleman battery powered too)

            Hot Water Heater: 220v will not be powered.
            Oven: 220v will not be powered (Have propane burners and BBQ as well as Fireplace cookware)
            Microwave: 750w ... not sure... don't use much
            OK is this house in a city with commercial AC available? If there are no codes to deal with you can do something unconventional at this low of a power level and no thave to spend a fortune for it. You just need a portable genny on wheels with a umbilical cord that matches your Inverter connection. Unplug the Inverter, plug in genny, or a dozen different ways to skin this cat.
            MSEE, PE

            Comment


            • #21
              Originally posted by Sunking View Post
              OK is this house in a city with commercial AC available? If there are no codes to deal with you can do something unconventional at this low of a power level and no thave to spend a fortune for it. You just need a portable genny on wheels with a umbilical cord that matches your Inverter connection. Unplug the Inverter, plug in genny, or a dozen different ways to skin this cat.
              It is in the county at 5500 feet, and the power is quite good. I hired an electrical contractor 4 years ago to completely re-wire from the 1950s funky electrical and have a 100 amp panel. Squirrels had eaten the wires and when the electrician opened the wall inside acorns fell out. So he used metal conduit throughout. The inspector made him put in 10 feet of copper for grounding and I had a whole house surge protection device installed. I also have POTS and DSL that works pretty well.

              Last summer there was a flash flood and someone died on the mountain. I am expecting El Nino (or at least preparing for it) just in case next winter is rough.

              So I have capacity for lots of power but don't have air conditioning, forced air heat (use fireplace most of the time and space heaters the rest). I do have a 220v electric oven/range and microwave, but also plenty of camping style cooking devices and a fireplace where I have been practicing cooking.

              Since I own the generator already and it gives me a pretty comfortable survival mode I would like to use it even if it means I must be careful with what I turn on and forgo hot water. I can always get a bigger generator later and if I do a transfer switch for all the circuits makes sense.

              I also do want to make sure that I could add a solar panel, charge controller and inverter that can plug into the same place the generator goes, in case I want to play with solar. As a matter of fact, a 300 w panel with MPPT gives me more amps than my generator does!

              Comment


              • #22
                Originally posted by Sunking View Post
                GFCI needs no ground and no they are mutually exclusive.

                I think you mean "no they are not mutually exclusive."

                If there is a ground-neutral bond ONLY at the generator and not anywhere downstream in the wiring system, then a GFCI output on the generator will work fine.
                The generator will also work fine without a GFCI output, but may not meet OSHA requirements.
                SunnyBoy 3000 US, 18 BP Solar 175B panels.

                Comment


                • #23
                  Originally posted by inetdog View Post
                  I think you mean "no they are not mutually exclusive."

                  If there is a ground-neutral bond ONLY at the generator and not anywhere downstream in the wiring system, then a GFCI output on the generator will work fine.
                  The generator will also work fine without a GFCI output, but may not meet OSHA requirements.
                  I had asked if neutral-ground bonding and GFCI were mutually inclusive (ie if you have one, you must have the other). As you and Sunking explain, the answer is no. You also add another point that helps explain the problem, if I understand you, and that is that the ground-neutral is only a problem for the generator if the same condition exists downstream. Then I presume you need the transfer switch to also switch the neutral which is more complicated, potentially less understood by electricians and would entail more labor. Not that I really understand all of this yet, but the Reliance tech support said that in that latter case the transfer switch then becomes the main breaker box and your original box becomes a sub panel. This means that the labor is equivalent to putting in a completely new electrical panel.

                  Now that this is cleared up, I thought of another thing for me to research, unless you guys know. If the transfer switch has a separate switch for each circuit which is engaged manually at the time of the power outage, would leaving a switch on the transfer box un-selected mean that one could have the original grid power to one circuit while isolating the selected ones?

                  Sorry for the wordy sentence. Could I engage one or two circuits through the transfer switch to take generator or solar power while the others (eg hot water heater, stove, etc) remain powered by the grid? That would be an ideal way for me to experiment and test alternative power sources.

                  ### Edit ###
                  I called Reliance and asked the questions. He confirmed that since there was no ground neutral bond that any
                  of their switches would work, actually any switch would work.

                  He said that their product is unique in that each switch is independently operated. So if I have 6 or 10 circuits controlled, I could leave some powered to the grid and power others via the generator. He also said that their transfer switch is pre-wired so that the actual job is a 20 minute job, excluding mounting the panel and potentially putting the input away from the panel. They have videos on their web site. Also he said that since it is installed on the "load side of the branch circuit" many homeowners do this for themselves from the instructions on their web site.
                  ##########

                  Comment


                  • #24
                    Originally posted by lkruper View Post

                    He said that their product is unique in that each switch is independently operated. So if I have 6 or 10 circuits controlled, I could leave some powered to the grid and power others via the generator. He also said that their transfer switch is pre-wired so that the actual job is a 20 minute job, excluding mounting the panel and potentially putting the input away from the panel. They have videos on their web site. Also he said that since it is installed on the "load side of the branch circuit" many homeowners do this for themselves from the instructions on their web site.
                    ##########
                    If the transfer switch (MTS) is transferring the feeder to a panel (L1, L2, maybe neutral) and there are any 240V loads the switch MUST transfer L1 and L2 at the same time.
                    And if the neutral is switched it should open L1 and L2 before it opens the neutral and then close the alternate neutral before it closes the alternate L1 and L2.
                    The alternative to a feeder transfer switch is the circuit-by-circuit transfer switch. These are often combined with a built in ammeter you you can see how much load you have energized to the alternate source.
                    You have to be very careful that any MultiWire Branch Circuits (MWBC) which have L1, L2 and a single common neutral be transferred at the same time, just as you would for a 240V (L1-L2) circuit. The transfer panel will typically have one or more pairs of switches with a handle tie for that purpose.
                    SunnyBoy 3000 US, 18 BP Solar 175B panels.

                    Comment


                    • #25
                      Originally posted by inetdog View Post
                      If the transfer switch (MTS) is transferring the feeder to a panel (L1, L2, maybe neutral) and there are any 240V loads the switch MUST transfer L1 and L2 at the same time.
                      And if the neutral is switched it should open L1 and L2 before it opens the neutral and then close the alternate neutral before it closes the alternate L1 and L2.
                      The alternative to a feeder transfer switch is the circuit-by-circuit transfer switch. These are often combined with a built in ammeter you you can see how much load you have energized to the alternate source.
                      You have to be very careful that any MultiWire Branch Circuits (MWBC) which have L1, L2 and a single common neutral be transferred at the same time, just as you would for a 240V (L1-L2) circuit. The transfer panel will typically have one or more pairs of switches with a handle tie for that purpose.
                      I am looking at an outdoor version of this one -> http://www.amazon.com/Reliance-Contr...ransfer+switch

                      According to the tech, it could handle both 110 and both legs of 220v.

                      Comment


                      • #26
                        Originally posted by lkruper View Post
                        I am looking at an outdoor version of this one -> http://www.amazon.com/Reliance-Contr...ransfer+switch

                        According to the tech, it could handle both 110 and both legs of 220v.
                        Yup, using one or both of the red marked switch pairs at the bottom of the column.
                        The "Also Viewed" display shows the ten circuit model with ammeters built in.
                        SunnyBoy 3000 US, 18 BP Solar 175B panels.

                        Comment


                        • #27
                          Originally posted by inetdog View Post
                          Yup, using one or both of the red marked switch pairs at the bottom of the column.
                          The "Also Viewed" display shows the ten circuit model with ammeters built in.
                          Would this cable work?? http://www.amazon.com/dp/B002IZJD5S/...I34V3FHJS60W2O

                          My generator has two female 110v outlets and the transfer switch has the maie 4 prong 30 amp 220 input. (http://www.amazon.com/Reliance-31410...ransfer+switch)

                          Comment


                          • #28
                            Originally posted by lkruper View Post
                            Would this cable work?? http://www.amazon.com/dp/B002IZJD5S/...I34V3FHJS60W2O

                            My generator has two female 110v outlets and the transfer switch has the maie 4 prong 30 amp 220 input. (http://www.amazon.com/Reliance-31410...ransfer+switch)
                            You have not told us enough about your generator.

                            The adapter you list will take the output of one of the 120v receptacles and connect it to ONE side of the transfer switch or other wiring. It will not give you 240V nor will it give you opposite phase 120.

                            Does your generator have a 240V output option, or is it just 120?

                            The circuit-by-circuit transfer switches we have been looking at are designed to support 240V loads, but only if you supply them with a 120-0-120 input in the first place.

                            If you have only 120V loads in the house, and you can confirm that there are no Multi Wire Branch Circuits (MWBCs) where the cable run has two hot leads (L1, L2) and a shared neutral. An MWBC is not safe when only one 120V phase is available.
                            SunnyBoy 3000 US, 18 BP Solar 175B panels.

                            Comment


                            • #29
                              Originally posted by inetdog View Post
                              You have not told us enough about your generator.

                              The adapter you list will take the output of one of the 120v receptacles and connect it to ONE side of the transfer switch or other wiring. It will not give you 240V nor will it give you opposite phase 120.

                              Does your generator have a 240V output option, or is it just 120?

                              The circuit-by-circuit transfer switches we have been looking at are designed to support 240V loads, but only if you supply them with a 120-0-120 input in the first place.

                              If you have only 120V loads in the house, and you can confirm that there are no Multi Wire Branch Circuits (MWBCs) where the cable run has two hot leads (L1, L2) and a shared neutral. An MWBC is not safe when only one 120V phase is available.
                              I ordered the cable today online and they knew exactly what I needed, a L14-30 Female to 110v 15 amp adapter with the two hots connected (bridged). They said they sold a lot of them during the last hurricane season for my application .... hooking up 110v generators to transfer switches. The link in my previous post is not that cable as it is the opposite configuration.

                              I do have 220v in the cabin for hot water heater and stove but I will not be having those hooked up to the transfer switch.

                              Comment


                              • #30
                                Originally posted by inetdog View Post
                                ... Multi Wire Branch Circuits (MWBCs) where the cable run has two hot leads (L1, L2) and a shared neutral. An MWBC is not safe when only one 120V phase is available.
                                I am curious for my own information. I put what you refer to as MWBCs in my current house when I wired it.

                                Now if I powered only one half the circuits with a 120V generator, on L1 *OR* L2, that alone would not be unsafe, would it? Assume I have no 240V loads. Does code address this?

                                Are you assuming in your statement that the HO would bridge L1 and L2, creating an unsafe situation on the neutral of MWBC circuits?

                                This is a hypothetical question. I would not normally connect a generator in this fashion. But... I can see someone doing such a thing, and placing critical circuits to be powered by generator on one phase and leaving the other phase unpowered in a power outage. Note I am asking about a non-solar application, where grid and generator power are the only options. Thanks, if you understand my long winded question.

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