Old Generator power low

[tcmtech]

Sounds like the both of you would fit right in with my rural neighbors as well.

We still do the helping each other out stuff as well. You can probably guess who is the one here that always has a few generators or other equipment that is available to be borrowed any time.
I am also the one who plows the snow for free and will do welding for free if they stop by while I am working on something too. But I dont have to grow a garden in the summer which I like!

 

[Soloboss]

So if I stop by and need a little welding done you'll help me out? Cool. It's only 1000 miles. And 20 hours. I'll bring pie if you have coffee.

 

[Reloadron]

So if I stop by and need a little welding done you'll help me out? Cool. It's only 1000 miles. And 20 hours. I'll bring pie if you have coffee.

LMAO, and if ever in Cleveland the coffee is here. She grinds beans on weekends and for visitors. Personally I'll have a beer.

TCMTECH covers it well (and plows which good plowing is a science) in that there is no substitute for good neighbors. I thank God we have neighbors like you guys have.

As to heilos, those little creatures are tough to manage and learn. I also love aviation and one good thing about Cleveland is the generally annual air show. Being a former Marine Air type I love it when the Blue Angles are in town.

I am a Viet Nam vet and when we are out to dinner if we see a soldier, sailor or Marine out with their girl or wife their dinner is on us. Just a way to say thanks and we appreciate your service. At the air shows if I visit a beer booth and see a GI buying a beer, it's on me.

Just something about apple pie and a good hot dog (prefer skin type all beef) I will take to the grave. Much like the value of good neighbors.

Ron

 

[Soloboss]

Mrs Ron only uses a conical burr grinder I hope. Yes they're slow, but you can have a beer while you wait.

Tcmtech - Doing good things for our guys is always in style. (I could get really political about our current administration, but That's too far off subject). Anyhow, I'm also an aviation fan - primarily a big fan of prop driven planes. I'll never take to the sky in my own plane, but a friend has a couple of planes and he designed and built and flew his own hot air balloon this winter. I am a fan of Microsoft's Flight Simulator and learning to fly and navigate by the numbers. I have a custom DC-3 in the sim and I spent a whole year flying it around the world in real time.
Are we far enough off subject yet or shall we continue?
I think the personalities that cross paths on these forums is great. So many good folks that I wouldn't get the chance to meet otherwise.
Most enjoyable. And with a good dog, a beer and pie, I may never leave!

 

[Reloadron]

Well back on topic once things are setup you will have to share the setup and how things work out. I am sure it should bring your parents some security.

Ron

 

[Soloboss]

Well back on topic once things are setup you will have to share the setup and how things work out. I am sure it should bring your parents some security.

Ron

Dad will not spend the money for a transfer switch. My brother in law is a commercial salesman for a large Michigan power company and he and I are not in favor of dad using just memory to get the connections and switching correct.
I saw an Interlock plate system that looks to be cost effective. The $225 generator is a good thing. Doubling the cost by adding $150 for the interlock, $50 for the power cord and a pair of breakers and he's going to tell us to just leave the generator in the garage. I'm afraid he'll end up with a suicide cord-set.
I'm looking for something extremely cost effective - even if it's crude.

Hey, I'm a cheapskate, but not a fool. My current system is temporary but it works. I simply put one end of each of my two cords in a lock box. The lock box key is on a wire-tie trapped under the cross bar on the mains. To use the cords I MUST flip the mains to OFF, releasing the loop holding the key. That key unlocks the cord ends, I run my power lines to the garage drop and connect. Again, this is temporary and I'm accumulating the stuff to do it correctly.

 

[Reloadron]

Let me think about this awhile. Wondering if I have anything in my junk that may be of some use to you. I completely understand your plight.

Ron

 

[john1]

Hi Soloboss,

I am very interested in your temporary but effective solution.
Having read and re-read your description a few times,
i'm afraid i am still somewhat confused by it.

My current system is temporary but it works. I simply put one end of each of my two cords in a lock box. The lock box key is on a wire-tie trapped under the cross bar on the mains. To use the cords I MUST flip the mains to OFF, releasing the loop holding the key. That key unlocks the cord ends, I run my power lines to the garage drop and connect. Again, this is temporary and I'm accumulating the stuff to do it correctly.

Maybe it is clearer to other readers,
maybe someone could help me to understand this arrangement.

I can sort of guess what some bits are, but its still not clear.

Cheers, John

 

[Soloboss]

Right now I feel like I have the eyes of this thread looking over my shoulder watching to see how I handle this.
Without an interlock, a transfer switch or some method to GUARANTEE the mains are off before generator power is applied to the box, there is always a chance that someone could forget to open the main breaker resulting in a danger of electrocution to linemen, destruction of your generator and fire.

What I have addressed is a no-cost way to ensure that I CANNOT connect my generator to my house circuits until I turn OFF the main breaker that feeds the utility power into my box. I use a custom made interface cord designed to connect from my generator to my house electrical circuit. For reasons of liability I'll not discuss the make-up of that cord. The purpose of this discussion is simply to provide a foolproof way to ensure my mains are turned OFF before I apply generator power to the household electrical circuit.
SO, the end of my special cord that interfaces with my garage outlet is locked in a simple plastic box. It's just a 4" square electrical box - a plastic one. I padlock the plug into that box so it cannot be used. The padlock has a key. The key is attached to a wire tie that is passed under the cross bar of the mains in my household power box. It is stuck under the cross bar and I can't remove the key without flipping the breaker off - then the key falls on the floor. Again, to get the key needed to unlock my special cord so I can use it, I HAVE TO FLIP THE BREAKER OFF.
There is a down side to this. When neighborhood power is restored, I have to remove the generator from the circuit and lock up the cord properly. My method is not as good as an interlock or transfer switch. But I'm working on it.
Mark

 

[tcmtech]

Around here we just go out and flip the main disconnect lever from Line to Off or Aux and either use the dedicated feed from the aux input or just back feed the nearest available welder outlet.

I always find it so strange that people have such incredible concerns over back feeds. Its smart to think about it but for the most part is not all that realistic of problem.

First off linemen never ever work on down lines without having both ends of the down section mutually tied to a shorted ground so even if you back fed your service it would be going into a dead short most likely.
Second very few people have a backup generator that could even power their own house at normal loads let alone back feed and power their surrounding neighbors houses at their normal loads together.
Even if they did have a gen set big enough its highly unlikely the main breaker or fuses for anyones home could carry anywhere near enough power to hold up the whole neighborhood.
Especially since anytime the power has been off for any Length of time once it is sent back to all the houses most will have multiple higher powered appliances all trying to all start at once. That power draw alone would trip the breakers on the supplying system.

I used to have a 35 Kw PTO driven gen set with 50 Kw surge capacity and I know that would have a hard time carrying just my two neighbors that have all electric heat individually let alone together along with the other two neighbors and myself who are all on the same primary feed circuit for my area of the country.

I have an old 80 Kw with a 100 KW surge capacity industrial gen set I am fixing for a friend that could carry every one but my 200 amp service still couldn't carry enough power for everyones combined loads anyway and it would just pop the primary fuse in the pad transformer that supplies my farm if I tried.

 

[Soloboss]

So if I forget my main and plug in my 5kw genset I won't light up my whole block? I can't run my house and the neighbor's houses from my two 20 amp breakers? Boy, the sales guy sure gave me a line! LOL!
My dad-in-law dropped a kilobuck on an electric start genny and another large on the transfer switch. It's pretty cool for a manual system. That's just too spendy for me and my budget. I want a basic level of fail-safe. Start the genny to warm it up a bit, flip the main OFF, grab the key and unlock the cord and plug that in and I'm golden.

When I show up with pie, make sure you have enough electricity to run the coffee pot. I'd bring the coffee too but it would get cold.
G'nite all.

 

[john1]

Hi Soloboss,

As tcmtech has already mentioned, workers on electrical supply services are well aware of the possibility of back-feeds from other generators. Not only small domestic sets but larger units which may be intended for factories or small industrial estates as back-ups.

I think that the most likely problem of the interlocking arrangements faced by the small domestic set, is the electric mains coming back on line while the generator is running.

I personally know a person who took account of the back-feed situation, and made sure that he switched out the mains supply before feeding his house from his small generator.
This was fine the first time.
He turned off and removed his generator when the mains came back, then switched back to the normal electric supply.

That was fine second time too.
Some time ago, we had "rolling power cuts" for a few months here in the UK.
They would typically last for a few hours at peak times in selected areas.
I forget exactly why they occurred, but they were very annoying.

On the third occasion when his utility power supply came back on,
he thought he would do it a little bit differently.

He thought he would maintain the supply to his house by switching back the electricity supply, then removing his generator.

Well it didnt quite work like that. He bust his generator, and i think he blew a fuse on the generator feed too.
Fortunately the damage was minor, i think the diodes were shot.
And his generator was out until i repaired it.
But it gave him a start, and i think he was much more careful after that.

********************

Ive been interested in interlocking systems of various types for many years. I first noticed my interest when i was an apprentice, a long time back now.
The small toolbox i used most was a small metal carrying type, lockable with a tongue of metal that went through a slot in the lid, and a padlock goes in the hole in the tongue.
A very common type of padlock arrangement on a small metal toolbox.

Occasionally the work was outdoors, or in awkward areas, and the open toolbox would be next to me, and that where i would put down any tools i was using, and any bits of stuff associated with what i was doing.
After finishing i would make sure everything of mine was back in the box, then close the box and get back.

That was fine mostly, but a couple of times i shut the keys in the box. Not often but enough to make me think, cos it meant cutting off the padlock and getting another one unless i was lucky enough to find its spare key.

Finally, after what seemed to me to be a year or so, a solution came to me.
There are two types of padlock. The type which are locked and unlocked using a key, and the type which lock when you squeeze them shut, you need the key to open this type.
All i had to do was to get the type of padlock which needs the key to lock it.
Then i can't lock my keys in the toolbox. This solution was so simple, it hit me like a smack in the ear.
I changed the padlock that day, even though it wasn't necessary.

********************

Dont worry too much about people looking over your shoulder, waiting to jump on you if you do something daft.
I used to feel a bit like that, but you've got to do start doing something really dangerous before anyone here starts kicking off.
Like playing around with generators and utility electricity supplies.

Thanks for the picture, a picture says a thousand words.
I see now exactly what you mean.

If you should happen to think of a simple arrangement which does cover it both ways, please post it as i would like to know.
Haven't thought of one myself yet, but i feel there would be something simple along the lines that you have already.

Regards, John

 

[Soloboss]

Hey John, that's a pair of dandy stories. Makes the point really simply. The key situation is super simple. It's not fool proof because there is no limit to a fool. They'll always find a way around whatever you do. But it is a simple reminder and that's what I wanted. Something that would always remind me to simply OFF the mains. Mission accomplished. Making a gadget that requires the key be returned to allow the mains to be reset is a bit more complicated. The sliding-plate interlocks sold online are hard to beat. I don't like the $150 part, but they do have to make a buck after the marketing, manufacturing and shipping/handling. I may just make a cardboard template and whittle one out of a metal plate. Slides are simple. Pop rivets are cheap. It doesn't have to be elegant for my use, it just has to work. When I get a plan for something simple, I'll post it. OOH! I'm having happy thoughts already! I'll be back.
Mark

 

[Soloboss]

Gents, I've returned with another question.
My brother in law works for Consumer's Electric in Michigan. He's concerned about back feeds. I told him we will isolate the house using the mains. He says mains will break the hot side but the neutral will still be running from the generator to the power pole. It is a common line, but it carries the full "Return side" potential as the two hot wires. That's why there are legal issues with people backfeeding without a Transfer Switch Panel. It is his thought that the Transfer Switch Panel DOES break the hot AND NEUTRAL conductors - fully isolating the generator from the pole. I was of the belief that the transfer switch common runs from the generator common wire to the transfer panel, to the main panel and to the white wire coming in from the pole. Who is correct?

Question #2 - the Craftsman generator that I took to my folks has a chassis ground lug with a note to ground it to an earth ground. There is an existing 240 volt line with ground in an outbuilding and I intend to run the 4 wires from the 240 volt twist lock to the red/black/white and ground connections of this outlet. Do I ground the generator or is the ground line of the 4 wire twist lock the proper ground for this application?

 

[tcmtech]

Your brother in laws concerns sound typical of most people who do not understand electricity. There is practical safety which is used by people who know what they are doing and then there is the dangerous safety which is applied by people who dont know what they are doing.
That is their over concern for safety can in fact put themselves and others at a greater risk simply from an over cautious and misunderstood approach to non relevant or unrealistic safety issues.
A "what if" can be a very dangerous thing in the wrong hands!

The neutral lines being permanently tied together from both sides of the system have no negative effect and are thus never disconnected. The common lines and the earth grounds share a common connection as well.
If power can not go back thought hot lines it has no way to complete the circuit and send any power back through the system.

If your gen set has a four line connection then consider that to be the correct way to use it.

 

[Hero999]

I don't know about where you live but in my house there's a double pole switch on the consumer unit where the power enters the house and before that there's a 100A fuse and a single pole switch. I imagine that double pole is use because it completely isolates the mains: just isolating the phase isn't always good enough as the neutral can potentially break.

Any way, as mentioned above, back feeding isn't an issue, as long as the phase is disconnected because it's not a complete circuit. Ask your brother in law to draw a diagram showing why keeping the neutrals connected poses a risk of backfeeding.

 

[Reloadron]

Well, this is a reasonably good read on the subject and has the emphasis on US mains:

When AC line voltage is normal, a TS allows powering the load from the
grid. When AC fails TS connects the load to the generator while
isolating it from mains. Connecting any power source directly into any
point of electrical wiring without a transfer switch is illegal and
dangerous because of so called backfeeding. Backfeeding (or
interconnection) is supplying electricity from your wiring system back
into electric grid. It energizes the line transformer serving your house
and poses an electrocution hazard for utility workers and for your
neighbors who may not know the voltage is present in the line. In any
case, your home generator most certainly will be overloaded by your
neighbors' loads in the disconnected local portion of the grid or
damaged if power is restored while it is backfeeding.

The standard U.S. household electrical service is 120/240 volt single
phase. It normally has two black "hot" wires and white grounded neutral.
The nominal voltage between each line and neutral is 120 VAC and between
two lines is 240 VAC. Note that both lines still belong to a single
phase- they are obtained by grounding the centertap of the utility
transformer. For such a system a generator transfer switch should be
double pole double throw (DPDT) "break before make". Double throw means
you can place or throw it into two positions (off position is not
counted). Double pole means it transfers both line wires (poles). The
neutral is normally continuous and does not have to be switched unless
your genset is equipped with a GFCI. "Break before make" means it
disconnects load from one source before connecting it to another one.
Older 2-wire 120 volt residential systems require a single-pole double
throw switch. Likewise, a three-phase generator would need a three-pole
device. The TS generally should be installed within 2 feet of the main
distribution panel and 30 feet of your genset inlet box.

Normally an electrical transfer switch for home generator has three
positions: LINE, OFF and GEN. When switching between LINE and GEN, it
always passes through the OFF position. Such break prevents arcing or
short circuits during the transition. If power rating of your genset is
not sufficient to power the entire house, you may install an additional
distribution panel (a subpanel) and hook up the essential lines your
want to backup to this panel. This sub-panel will then be wired to the
transfer switch. Many commercially available TS come already with a
pre-wired panel.

Additionally attached is an image depicting what a manual transfer would look like. Note that both the neutral and ground are tied at the panel. The neutral is not disconnected or broken at any point and should not be broken.

The back feed issue is one of controversy and always has been. Yes, linemen check for such things but that is here nor there. The issue becomes legality and liability. For US applications the NEC 2008 and the NFPA 2004 from what I read don't overly get into it and leave it to local and state codes (laws). The consensus has always been it is better to err on the side of safety.

Grounding is required and should be done properly. When I put in the emergency fixed generator I drove an 8 foot ground rod into the ground and when the city inspected the first thing they looked for was my grounding. These rods are available from Lowes and Home Depot and are actually a copper plated steel rod. When using a portable unit a clamp can be used to connect generator frame to the rod.

You want effective and you want safe but you also don't want or need a transfer system that will exceed the cost of a generator.

<EDIT> The quote and image were taken from here.

Ron

 

[Soloboss]

Lots of good comments coming back. As always, I'm reading everything and taking it all in. I've done a good deal of on-line searching and I have found situations that appear to be constant for portable generators. I'm not dealing with a generator with permanent wiring and there is no GFCI, so it's pretty simple.

Genset WITHOUT GFCI;
#1 - UL approved and NEC approved devices don't break the neutral for a portable generator connection. (note: Gensets with GFCI require a 3 pole with neutral break)
#2 - If the portable has a 4 wire connection - use it. Or simply run extension cords from the generator to appliances to be powered and watch the cord rating versus appliance load.
#3 - An INTERLOCK devise is acceptable and a transfer switch is better to provide an interlock between the mains and generator feed.

One last question - until the next one; If we simply use extension cords, I need to ground the generator, right? The generator does have a ground lug that needs to be taken to an earth ground rod.

 

[Reloadron]

One last question - until the next one; If we simply use extension cords, I need to ground the generator, right? The generator does have a ground lug that needs to be taken to an earth ground rod.

I would. You don't want a person being the path to ground in the off chance the housing (cage) somehow becomes hot.

Ron

 

[Soloboss]

I can make a better argument FOR grounding it than AGAINST grounding it. I'll drive a ground rod next time I'm home.