installing non-automatic transfer switch

Discussion in 'Electrical Forum discussion & Blog' started by zunden, Jan 8, 2011.

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  1. zunden

    zunden New Member

    Messages:
    11
    Location:
    DC, USA
    I have questions about installing a Gen-Tran, 30 amp, non-automatic transfer switch, #301660, just to the right of two, C-H 200 amp service panels(400 amp service) on my basement concrete wall. My 60 amp feeder breaker goes in the right service panel. I want to provide emergency service to my 240V, 20 amp well pump and 120V, 20 amp furnace circuits, currently wired to the right panel, and to my 20 amp small appliance/refrigerator circuit and 15 amp bathroom lighting/ventilation circuit, currently wired to the left. My questions are:
    1. Should I splice the neutrals of the circuits in the left panel to the neutral/ground bar in the right panel which contains the feeder breaker?
    2. Can I leave disconnected circuit breakers in the service panels in place?
    3. Must the spliced conductors from the service panels to the transfer switch be marked?
    4. Do the four emergency circuits overload my 30 amp transfer switch by code? How do I calculate the load for eating area small appliances in the small appliance circuit below?
    Well pump full-load current = 6.9 amp(Table 430.248).
    Furnace full-load current = 13.8 amp(Table 430.248); EIM(controller) = 0.2-1.0 running
    amps specified in installation manual.
    Small appliance circuit: refrigerator label load current = 7.2 amp[440.6(A)]; 13 – 115V
    duplex receptacle outlets for eating area small appliances = ? amps by code.
    Bathroom lighting/ventilation circuit: 7 fixtures with fluorescent bulbs = 1.2 amp; 2
    ventilation fans = 1.8 amp; 3 – 115V duplex, general use receptacle outlets = 0
    amp[220.14(J)]
    5. For the branch circuits, does code require calculation of allowable ampacity of the spliced conductors from the service panels to the transfer switch, or can I use the 90°(THHN) #12 AWG provided by Gen-Tran? Existing wiring is NM-B, 12-2G for the 20 amp circuits and 14-2 for the bathroom circuit.
    6. For calculating allowable ampacity of the 90°(THHN) #6 AWG conductors provided by Gen-Tran for the 60 amp feeder service from the right service panel, what ambient temperature correction factor should I apply to the allowable ampacity in Table 310.15(B)(16)?
    7. Must I connect my portable generator's ground lug to an earth ground? If so, what is the best way? I have outdoor access to my home's ground electrode and steel wellhead.
    8. Is flush-mounting a Reliance power inlet box to the sheetrock interior wall of my garage about 12†above the slab okay? Only the cap will protrude about 1†from the wall.
    9. What areas of the NEC will the test allowing homeowner installation likely cover?

    Thanks for whatever help you can provide.
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    STOP!

    You said this is a thirty amp generator and will produce approximately twenty four amps continuously.

    To this machine you are going to add over 29 amps and expect it to carry it all?

    The easiest way to connect one of those small generators to you home is through the use of drop cords from the equipment to the generator. The cost of installing a transfer switch in the proper manner will end up costing more than the generator.

    A second thing about these generators is they don’t give a very clean signal. The voltage does not hold very steady and neither does the cycles. To use this generator could cause damage to electronic equipment.

    The end cap or male plug that the cord is connected to must be on the outside not on the inside close to anything.

    The grounded neutral is connected to the grounding electrode at your service. When this generator is connected to the dwelling unit’s wiring system then the grounded neutral must be separated on the generator. When this is done then the receptacles on the generator no longer have a fault current path and are dangerous.

    If the grounded neutral of the generator is not going to be lifted at the generator then it must be separated at the dwelling unit’s service equipment again a major issue.

    Remember that just because it works in no way means its safe. It is just as quick to set up the generator and temporally install cords through a part open window as it is to set up the generator and run back and forth switching circuits on and off to keep the generator from stalling out.

    Covered on the test I designed for DIY and generators entailed the following articles;

    Article 110 Parts I and II
    Article 200 Use and Identification of Grounded Conductors
    Article 210 Branch Circuits Parts I and II
    Article 215 Feeders
    Article 220 Branch-Circuit, Feeder, and Service Calculations Parts I-IV
    Article 225 Outside Branch Circuits and Feeders (with special attention to Part II)
    Article 230 Services Parts IV, V, VI, VII
    Article 240 Overcurrent Protection
    Article 250 Grounding and Bonding (special attention to Part II)
    Article 445 Generators
    Article 702 Optional Standby Systems

    These articles have a wealth of information concerning the installation of generators.

    Be advised that generators manufactured after 1-01-2011 that are smaller than 15kw will be required to have GFCI protection for all receptacles outlets. This in and of its self will mandate that portable generator be used with cords only or the neutral will be required to be switched at the building supplied. For reference see the 2011 cycle of the NEC in Article 590 and Section 6 (590.6).

    EDITED TO ADD:

    (3) Receptacles on 15-kW or less Portable Generators.
    All 125-volt and 125/250-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are a part of a 15-kW or smaller portable generator shall have listed ground-fault circuit-interrupter protection for personnel. All 15- and 20-ampere, 125- and 250-volt receptacles, including those that are part of a portable generator, used in a damp or wet location shall comply with 406.9(A) and (B). Listed cord sets or devices incorporating listed ground-fault circuit-interrupter protection for personnel identified for portable use shall be permitted for use with 15-kW or less portable generators manufactured or remanufactured prior to January 1, 2011.


    I though it would be nice to post the code section here for everyone to see. Notice that this section clearly says that any cord used on generators built before this date will require the GFCI protection in the cord used.
    Last edited: Jan 9, 2011
  3. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    Small portable generators and your home.

    A small 5500 watt generator will deliver around 4400 watts of continuous power that will be fairly clean. This is enough to power a couple small appliances such as a refrigerator and coffee pot. Maybe a couple of lights could be added but never use electronic equipment such as TVs or computers.
    For larger appliances such as well pumps will almost max out one of these generators. Appliances such as water heaters and electric heat is more than one will safely handle.

    A small generator will cost around $700. A manual transfer switch is around $300, the material to install the transfer switch around another $300 and finally a day of labor to make the installation another $500. Now we have $1800 in a generator that will require us to constantly run back and forth switching off one circuit to switch on another to keep the generator from stalling.

    Now if this isn’t enough to cause one to stop and think about what they are doing one needs to know that with today’s technology with computers, flat screen TVs, and such other electronic appliances that we are almost guaranteed to want to connect to these small generators all require a fairly constant voltage with a fairly clean signal. This is something that this small generator just can’t supply. I personally know of microwave ovens that were damaged by these small generators. Yes it was mine.

    These small generators do not have automatic voltage regulation that comes with the larger generators. The voltage will drop as the load increases as well as the cycles will drop as the load increases. Motor loads such as well pumps will cause a large voltage drop as well as a drop in the frequency. This will affect electronic equipment such as TVs and computers and have been known to damage them.

    Having dealt with generators for several years and yes I own two small generators I highly recommend that you do as I do and use cords (be sure to use large conductor cords) and connect each appliance or a lamp to the generator individually instead of all this transfer junk that is nothing more than a hassle and can violate the warranty of some of your electronics.

    At my house such things as the TV, computer, and other electronic equipment is never turned on during a power outage. It just cost too much to replace and I for one can do without either for a very long time therefore the couple of hours without power sure does not hurt.

    The one thing that can’t be done is use a go-cart in the place of a limousine. If one wants a limousine then one will have to spend the monies to purchase the limousine but one can’t change a go-cart into one.
    The small generator is nothing more than just that, a small generator. If what you want is power to your house then spend the thousands of dollars it will cost but please don’t try to use a VW Bug as a school bus.
  4. zunden

    zunden New Member

    Messages:
    11
    Location:
    DC, USA
    Thanks to jwelectric

    Jwelectric –
    I really appreciate your warnings and advice. I could certainly get through a power outage with drop cords. Would this mean installing a plug and receptacle in my furnace and well pump circuits?

    After hours of reading and considering online advisories and cited NEC provisions, I realize that I simply lack enough basic understanding of ac wiring to follow your explanation of the difficulties in providing a fault current path for the generator receptacles. I hope that the county inspectors office or manufacturers' reps will go into the detail I need to understand the issues and perhaps show me a way in which I can install the transfer switch properly.

    Thanks for helping to keep a lot of people safe. - zunden
  5. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    Just like in a simple flashlight current is flowing from one end of the batteries to the other end through the light bulb. This current that flows leaves one end of the batteries and returns to the other end through a complete path. Should this path be broken then the bulb goes out.
    This same principle is true in all current flow be it AC or DC. The current must return to its source.

    In the event of a ground fault we want to return this faulted current back to the source. One might ask, “Just what is a ground fault?”
    As defined in the NEC, Ground Fault. An unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non–current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth.
    I use the analogy in the classroom that something is very wrong and it is a hot wire’s fault.

    To be able to send any faulted current that is now traveling on all exposed metal surfaces back to its source we do a process outlined in the NEC called “bonding”
    This bonding of the equipment grounding conductors and the grounded neutral at the service ensures that there is a low impedance path back to the source which causes the overcurrent device to open be it a fuse of circuit breaker.

    When installing a generator to our homes we for our own safety need to ensure that any and all circuits that might be used have this low impedance path back to which ever source we are using at the time be it the utility or the generator.

    The NEC requires that this bonding take place at the first disconnecting means in line with the supply source be it the utility which would be or main breaker or the first disconnect just beyond the meter, or the generator which would be the first place we connected our cord at the generator. Permission is given to allow this bonding to remain intact at the service equipment as long as the bonding is removed at the generator. Once this bond is lifted at the generator the other receptacles on the generator just lost their fault current path.

    Yes there would still be a path through the equipment grounding conductor of the supply cord but we have issues with this install. The size of this conductor could be affected because it is no longer equipment grounding conductor but a supply side bonding conductor and gets sized by Table 250.66 instead of 250.122.


    Using the transfer kits can be tricky to say the least. Most of these will require that the bond be lifted at the generator meaning that it would need to be reconnected should the receptacles on the generator need to be used. There should be instruction that come with the transfer explaining how it is to be connected. No matter which transfer you choose the male inlet will need to be on the outside of the home. It will need to be hardwired to the transfer from this inlet box. The place for this inlet should be free from damage meaning the driveway is a bad choice.

    Also remember that this transfer does not clean up the signal either. It will still won’t have voltage regulation.
  6. zunden

    zunden New Member

    Messages:
    11
    Location:
    DC, USA
    Thanks again.

    jwelectric -
    Your follow-up explanation helps a lot. Perhaps I can identify my remaining misunderstandings most quickly by describing my best guess for the neutral and ground wiring of both my furnace circuit via a transfer switch and my generator:
    1. Disconnect the furnace circuit neutral from whichever of the two bonded neutral/ground bars it is connected to in the right main panel(400 amp service), and splice the neutral to the separated neutral bar in the transfer switch.
    2. Connect the separated neutral bar in the transfer switch to one of the two bonded neutral/ground bars in the right main panel with a white insulated conductor. This connection completes the low impedance, ground fault path for the furnace circuit back to the source, i.e., the utility transformer, during utility service operation.
    3. Connect the ground bar in the transfer switch to one of the two bonded neutral/ground bars in the right main panel with a green insulated conductor. This connection completes the ground fault path for the transfer switch enclosure.
    4. Connect the ground terminal on the generator(Honeywell HW7500E) to the outside wire running from the house to the ground electrode. Owner's Manual:
    “CAUTION Generator must be grounded to prevent electrical shock from faulty
    appliances.â€
    “Before using generator, a ground wire must be connected to the ground terminal.
    NOTE: The system ground is not connected to AC neutral wire. . . .â€

    Thus, as you pointed out, I have lost the fault path afforded by a grounded neutral and have to hope for the best with the grounding conductor in the supply cord or with upgrading to cord with GFCI protection.

    Thanks again. - zunden
  7. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    You are using a Honeywell generator with a Gen-Tran manual transfer switch. Is this correct?

    If so then the installation manual for the transfer will have the instructions included with it on how it is to be installed. Each and every one of these “death trap†transfer switches will wire differently. Well the comment of death trap might be a little strong but I just don’t like them.

    You will need to ensure that every circuit you are wanting to control comes into the transfer switch and the utility power hits one side and the generator the other.
    The bonding will occur in the service equipment so I am hoping this is from the generator its self.
    The generator will be connected to the grounding electrode system through the service equipment already in place and will not require any thing more. It the generator does not have the neutral separated then there will be a parallel path between the generator and the transfer switch which could deliver a pretty hard slap to you when you come in contact with the frame of the generator. Connecting the generator to earth will not prevent this shock.


    Be sure to run the inlet plug to the outside and do the plugging of the generator there and do not let the cord pass under a garage door as this could end up being a very bad mistake.

    I do believe you will find that using cords that pass through windows is a far better installation and does not impede into the house wiring system. It is also a lot cheaper and you will be less likely to try and fire up your TV or computer.
    With the generator connected to you home anyone turning on something as simple as a ceiling fan could prove to be disastrous to items such as TVs, computers, and such other electronic devices.

    As an electrician with over 40 years of field experience I do not have a transfer on my home. I do own two small generators one a 5500 and the other a 7500. I will use one to draw water for my livestock and the other for lights in the house. It is neither that I can’t afford a transfer switch or larger generator it is just I see no need for one in the Piedmont area of North Carolina. We are as I type having a snow and ice storm that may end up causing us to lose power sometime through the night. In the 59 years and seven months that I have lived here we have never been more than three days without power. At night we sleep and in the day we do not need any light. Anything else is a convenience and not a necessity except the water for the livestock.
  8. drick

    drick In the Trades

    Messages:
    392
    Right idea, wrong solution. The Gen-Tran is only going to work with one panel. You need to move all the circuits you want to power into one of the two 200 amp panels.

    No. you can purchase circuit breaker blanks for a couple of bucks each form an electrical supply house.

    No.

    I don't know enough about the model of Gen-Tran you are using to fully answer, but it the feeder breaker is 60 amps, and the Gen-Tran is rated for 60 amps (from utility power, not generator power) - which I'd assume it is if that is the breaker the documentation says to use - then your all set. Also its rated 7500W witch is 30A at 240 volts. Most of your loads are 120 volts. Therefore you actually have quite a bit of headroom left as it is now.

    Example 120V * 30Amps = 3600W
    Example 240V * 30Amps = 7200W

    Just a quick look at what you have listed for wattage leads me to question the well pump. You can't just convert HP to watts because there are major losses you are ignoring. I have a 1hp well pump and it draws well over 1000 watts. That said if all you are looking for is emergency power - well, heat, fridge, some lighting, and maybe a toaster oven you should be fine. I know this because this is the load I ran for 8 days almost 24 hours a day off my 6500W portable generator during an ice storm in 08.

    You do not need to derate. Use what is provided.

    Again don't worry about derating. Assume 1.0.

    You do not use the ground lug when using a transfer switch.

    The power inlet box must be installed outside.

    As has already been mentioned the power from a small generator is not clean power. The voltage and the frequency will vary. Electronics hate this and it can kill them. I would unplug all audio video equipment and computer equipment. The one exception is laptop computers. Their power supply converts AC to DC so they are unaffected by frequency changes and small fluctuations in voltage. Also during my eight day power failure I used a microwave and older TV I wasn't in love with every day with no problems so its not that electronics will absolutely fail, but there is a much higher probability of failure. In addition it is unlikely you will be able to sustain the generators maximum rated wattage at rated voltage for more than a few seconds if even that long. Assume you'll get about 80% of maximum rated wattage (not surge wattage, but maximum wattage).

    Also one last note, the total material cost for parts for a generator interlock kit for my panel, exterior outlet, wire and circuit breaker came to under $200.00.

    Oh and another last note if you generator requires an oil filter buy an extra one now. If you have a major storm and everyone hauls out their generators there will be a sudden shortage of generator sized oil filters.

    -rick
  9. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    Here is a good case in point------------

    I have just returned from my neighbor’s home where a tree limb pulled his service drop down. The power company told him to have the riser repaired and they would do the connection pre-inspection. I just did the repair but while I was there well………..


    While we were outside accessing the damage and figuring how much this was going to cost I heard the generator speed up. Neither of us though much about this as the small generator kicked in its governors and the motor started racing away as the well pump brought the water pressure back up (someone flushed a toilet).

    As we were rounding the corner of the house one of his kids came running out the door screaming out the top of his lungs, “Daddy, Daddy the TV just quit.” Low and behold the new 55 inch flat screen TV from Sears and the sound system that Santa brought is now a large boat anchor or other type of decoration but is no longer something to receive movies. By the time I entered the house I could smell the damage. He said that the TV was over three grand…. Oh well that was an expensive baby sitter and now it has quit. I can’t help but wonder if they can do without it now that it has been destroyed could they have done without it to start with.

    I just don’t understand how these folks get all that smoke into something like a TV but I do understand that once someone lets that smoke out the TV isn’t much good any more.

    I recon that if everybody would plug up their TVs and desktop computers to a small generator it might help the economy and put a few people back to work replacing all this expensive equipment.
  10. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    Drick

    Unless I am badly mistaken the transfer switch he has will have between 6 and 12 breakers in it for the circuits being supplied. These circuits will need to be brought to the transfer switch.

    The transfer switch will have a feeder rated at 60 amps that will supply the transfer from the utility and will switch off when the 30 amp breaker from the generator is switched on.

    The major problem is that is all the small breakers are on when the switch is made from utility to generator the generator might stall out. These circuits will need to be off when the transfer is made and then turned on one at a time.

    Your comment that you used all these appliance on your 6500 for 24 hours a day for 8 days might be a little misleading. Your generator is only capable of delivering 6500 watts and no more. These might have been the items you used but I very seriously doubt that they all were on for 192 continuous hours.

    Now let’s look at your math in a different way. His generator is rated at 7500 watts and this is all it will do no matter what amperage receptacle you are using. At 240 volts this would be 31.25 and at 120 volts it would be 31.25 not 62.5.
    Why?
    Because the receptacle for the 240 volt is rated at 30 amps and 30 amps is all it will deliver period. It does no double if we only use one half of the generator winding.

    I have a 200 amp panel does this panel double to a 400 amp panel if I only connect 120 volt circuits to it? No. The same is true with this little generator. It is rated at 30 amps and it doesn’t matter if it is one 240 volt load or a combined 120 volt load the 30 amps remain the same and is the max that this generator will carry.

    Well pump at 1 hp = 8 amps times 124% = 10 amps
    This pump will have a 48 amp start up draw

    The air handler with a there quarter hp motor = 13.8 times 125% = 17.25 amps
    This air handler will have a 82.8 amp start up draw

    Should this well and air handler be pulling at the same time the load would be 26.8 amps and more than the max of 24 amps that the generator will pull. 30 times 80 percent = 24 amps.

    This doesn’t leave much for anything else to run off of and should both kick on at the same time the generator is sure to stall.

    This is why I just use cords for what I need. My well pressure switch is cord and plug connected so just plug it into my 240 volt cord into one of my generators and we have water.
    A #12 cord brought into the house from the second generator supplies a table lamp and coffee pot, crock pot, or other item as needed. No transfer switch for me to run downstairs to flip off one switch and flip on another I just unplug and plug up something else. We heat with gas logs so no heat fan to connect.
  11. zunden

    zunden New Member

    Messages:
    11
    Location:
    DC, USA
    thanks; some final questions

    drick -
    Thank you much for your answers and advice.

    In regard to moving emergency powered circuits into one main panel holding the feeder breaker:
    Existing circuit wiring would require me to extend the NM-B for at least one circuit using a
    junction box, I guess. Would it also be acceptable to:
    1) splice the circuit neutrals to the separated neutral bar in the transfer switch, and
    connect the bar with a white insulated conductor to one of the bonded neutral/ground bars in the right main panel holding the feeder breaker;
    2) splice the circuit grounding wires of the two circuits in the left main panel to one of the neutral/ground bars in the right panel or to the ground bar in the transfer
    switch, and connect the ground bar with a green insulated conductor to one of the neutral/ground bars in the right panel; and,
    3) splice the circuit load conductors to the circuit breakers in the transfer switch?

    In regard to your discussion of the generator's capacity, particularly with respect to the well pump, I should have provided the following in my original post:
    My generator is a Honeywell HW7500E. The Owner's Manual lists Surge Power =
    11250W, Maximum Power = 9375W, and Continuous (Rated) Power = 7500W.

    My well pump is a Goulds ¾ HP. The label for the Franklin-Electric motor in the well pump lists s.f. Max amp = 8.0 amp. For what it's worth, the owner of the company which installed the pump told me that start pulls 16.5 to 18 amps and recommends a 20 amp breaker. But, Goulds, lists in online specifications a 20 amp breaker and a starting(surge) load of 9400W. The existing breaker in the main panel is a 25 amp.

    I noticed the agreement between you and jwelectric in warning me about the danger to my electronics and the danger of stalling the generator. I will type up guidelines for avoiding use of plug-in electronics, for opening circuit breakers in the transfer switch before throwing the interlocked feeder breakers, and procedures for avoiding simultaneous starting of the well pump and blower motors. I will post the guidelines with appropriate warning symbols on the transfer switch cover.

    One last question: I would like to install the power inlet on an outside wall at least several feet above grade in order to minimize wetness from snow. (My inlet is a Reliance PB30 with a horizontal plug.) At this height, my garage wall provides the easiest access to my basement through the use of an interior run of 4-wire #10 cable on the inside of the wall. What type of cable/conduit, attachment, and wall penetration devices would you recommend? The cable would turn 90° to enter the basement parallel to an end joist resting on the basement wall to which the panels are attached, and would have a run of 7' before dropping to the transfer switch.

    I can't thank you and jwelectric enough for your generous advice.
  12. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    Look at this link as see if this is the transfer switch you have

    http://www.gen-tran.com/assets/pdfs/MTSinstall.pdf

    Look at page 4 and see if this is what your transfer switch looks like. Does it have two breakers, one 60 and one 30 amp?

    Does it have space for 6 to 12 single pole and double pole breakers?

    Do you have a picture of your service and transfer switch?

    Any or all of this information is important before anyone can give you answers to the questions you are asking.
  13. drick

    drick In the Trades

    Messages:
    392
    Will it work, yes. Should you do it, no. The problem is you are trying to use the panel as a junction box. Generally when someone shuts off the main to a panel they expect all the circuits feeding out of that panel to be dead. Someone working on that panel years from now after you sold the house may not realize what has been done. Removing the circuits from the left panel and extending them using a junction box is the right way to do it.

    9400W sounds high, but if thats what the manufacturer says... Worst case you would have to shut down your furnace/air handler while you took a shower, but I doubt it will come to that.

    If the wire is going to run down by the sill plate in the garage it needs to be protected from physical damage. The easiest way for you to do this is with RNC (Article 352) which is essentially PVC. I would run 3/4 inch PVC (you can use 1/2 inch, but 3/4 will make for easier wire pulling) from your transfer switch all the way to the inlet and pull four #10 THHN conductors. It will be water tight and protected.

    -rick
  14. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Well, this takes the award as the wordiest bunch of posts in Terrys history. Some intesting knowledge here, but a bit boggling.

    Here is what I do in a power outage:

    Predicted less than 20 hours: Nothing. Candles and stay out of the fridge. Eat chips and sardines.

    Firestorm imminent or 20 hours plus?: My 8000 watt rig sits near the panel, and a 20 amp breaker serves as the INFEED from the generator.

    Deleted by JWELECTRIC as the advice was not only unsafe but illegal.
    The advice was a life safety issue.

    For everyone else that does not have a clue about what I wrote, get an AUTOMATIC switch, self exercising genset, a pro to install, and sit back in your barcalounger and watch the Simpsons while waiting for "life" to begin again.

    Or run extension cords, as suggested, but pretty hard to hook to a furnace or 240v submersible pump. And I think a bunch more dangerous than backfeeding the panel with the main off.
    Last edited by a moderator: Jan 12, 2011
  15. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    HAHAHA......I can guess what the backup power setup was that was deleted.....I probably do the same thing and just did a few months ago when my service cable was severed at the pole probably by a truck......I won't say what it is......
    I work in the generator field.......we sell, service and install them and service units up to about 1 MegaWatt.....18 years of doing this work and I was an electrician right out of high school........so I am reasonably carefull and have survived for 63 years....

    I repair electrical equipment.....welders, generators. I work around live voltage everyday......some welders today have 800-900 volts on their buss bars when powered up........Inverters....I am a Miller and Lincoln and Onan certified repair person.........In training schools live machines are worked on everyday......we wear safety glasses and I like to wear latex gloves.

    I am not saying electricity is not dangerous or that a novice should do his own electrical work......but some of what I read on here is just off the charts as far as rediculous.....

    Power failures happen in adverse condtions usually weather related. Makes messing with portable generators and extension cords a bit difficult if it's pouring rain, windy.....snow, lightning storms etc......I have a portable generator in my detached garage. I make a connection there and use it to power essential things in my house......
    Last edited: Jan 12, 2011
  16. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    better delete that last line, it might be dangerous.

    But really, its a bit sad that non-conforming information is automatically removed.

    My piece of illegal electrical work in a forest fire saved an irreplaceble home, while I watchd 30+ others burn.

    At least in some cases, they had generators, but no idea how to power them up quick and easy in an EMERGENCY.

    Backfeeding was not an issue as there were no standing poles for miles around.

    Exploding propane tanks and transformers all around make for quick solutions.
    Last edited: Jan 12, 2011
  17. Jim Port

    Jim Port Electrical Contractor

    Messages:
    156
    Location:
    Maryland
    I certainly hope that the garage is well ventilated so that carbon monoxide does not build up and enter the house. Waking up dead from CO poisoning doesn't sound like fun.
  18. zunden

    zunden New Member

    Messages:
    11
    Location:
    DC, USA
    more information on main panels and transfer switch

    jwelectric -

    I do have the series of transfer switch shown. My model is the 301660. It has interlocked 60 and 30 amp breakers provided by Gen-Tran and space for 8 full-size, single-pole breakers or 4 double-pole. On page 3, Gen-Tran specifies twice this capacity for this model, I believe, by assuming the use of half-size breakers. A home photo and scanned wiring diagram from Gen-Tran were too large to attach to this reply. The best online picture I found is at: http://patioenclosurekit.iim.bz/201...ansfer-switch-for-up-to-7500-watt-generators/ My 301660 is laid out just like the Model 501210 shown in the link you sent me.

    My 400 amp service uses twin Cutler-Hammer Model CH30JJM200N split neutral main breaker panels. Again, my home photos are too large for attaching here, and I could not find an online picture.

    Thanks once again.
  19. zunden

    zunden New Member

    Messages:
    11
    Location:
    DC, USA
    will do

    drick -

    I will move the two left panel circuits to the right panel with the feeder breaker, as you advise. Thank you for catching this safety issue. I would hope that my county's permit office would have done so, but who knows? Thanks also for checking my generator capacity. I can easily disable the blower motor from my VisionPro thermostat during water use. Finally, thanks for the cabling recommendations. I might spend extra for 10-3 UP and whatever size RNC it calls for.
  20. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,557
    Location:
    North Carolina
    The only thing you need to do is to move the circuits that you want to have on the generator to the small transfer panel. Move all conductors ie: black, white, and bare equipment grounding conductor.

    Do not and I repeat Do Not try to use the generator to supply one of the 200 amp panels.

    Use the neutral and two hots from the transfer 60 amp overcurrent device to supply the utility power to those circuits you move to the transfer panel. During a power failure the 60 is turned off and the 30 is turned on to supply those circuits that you moved.
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