Reverse polarity with Honda EU2000i
Moderators: CaptPatrick, mike ohlstein, Bruce
Reverse polarity with Honda EU2000i
Running power from shore and my panel indicates all is well. Only have batterry charger and air conditioner hooked up. Have not run the Marine air yet since it is not true shore power, just extension cord to the house.
Getting power from honda 2000 generator and I get the red reverse polarity indicator light on my panel. I am lost as to why one power source is ok and the other is not. Any suggestions would be great, I really want to get that air conditioner running.
Getting power from honda 2000 generator and I get the red reverse polarity indicator light on my panel. I am lost as to why one power source is ok and the other is not. Any suggestions would be great, I really want to get that air conditioner running.
- Harry Babb
- Senior Member
- Posts: 2354
- Joined: Jun 30th, '06, 21:45
- Location: Fairhope Al
- Contact:
Harry,
so just get spare extension cord, cut, swap the black and the white and it will work? And only use it with boat or will the cord still function normally with house outlet and power tools?
Does this mean all portable generators will not work properly with a boat until cord is modified?
I think I understand your fix but do not understand why it is like that to begin with. Thanks
so just get spare extension cord, cut, swap the black and the white and it will work? And only use it with boat or will the cord still function normally with house outlet and power tools?
Does this mean all portable generators will not work properly with a boat until cord is modified?
I think I understand your fix but do not understand why it is like that to begin with. Thanks
I take it by your comments that the cord you are using with the gen set is a commercial wired cord that no one has rewired.
If that is the case before cutting anything, get the meter out and check the power behind your panel.
Use the ground on each circuit for one meter lead on 120vac scale.
Touch the other lead to both the black(hot) and white(neutral).
You should get no reading between the green and white, only green and black.
If you get a reading from green to white, there is your problem. Check both shore and gen even though you don't get a problem on the shore. It could be the reverse polarity is not wired correctly and the shore is wrong and the gen is right.
I've run into that before.
The VOM meter is your friend.
If that is the case before cutting anything, get the meter out and check the power behind your panel.
Use the ground on each circuit for one meter lead on 120vac scale.
Touch the other lead to both the black(hot) and white(neutral).
You should get no reading between the green and white, only green and black.
If you get a reading from green to white, there is your problem. Check both shore and gen even though you don't get a problem on the shore. It could be the reverse polarity is not wired correctly and the shore is wrong and the gen is right.
I've run into that before.
The VOM meter is your friend.
Yeah, the cord is the standard home depot type cord. I know it is not the right way to do it, but good enough to run low amperage stuff like the battery charger while I am working on the boat. I Never leave it unattended.
The shore power source is actually not even the house, it is the neighbors shed. But if it were wired wrong I would think that I would get the reverse polarity light from that. I will follow your instructions in the A.M. to verify. This whole green, white and black thing is new to me. I have never messed with it until today. Might be time to get an electrician. Definitely time to get a beer. Thanks fellas.
The shore power source is actually not even the house, it is the neighbors shed. But if it were wired wrong I would think that I would get the reverse polarity light from that. I will follow your instructions in the A.M. to verify. This whole green, white and black thing is new to me. I have never messed with it until today. Might be time to get an electrician. Definitely time to get a beer. Thanks fellas.
- Harry Babb
- Senior Member
- Posts: 2354
- Joined: Jun 30th, '06, 21:45
- Location: Fairhope Al
- Contact:
Hang in there Kevin........its not time to call an electrician yet........its really not that difficult. Once you get a grip on it you will certainly be and feel more confident when you hook up other AC appliances.
Bruce did a much better job of expaining the detail than I did.....just follow his instructions.
About 25 years ago a friend asked me to install a trailer hitch on his motor home. I went to his house early one morning to look at the situation. Well.......he had the power cord (Shore Power) pluged into a receptical that was wired up for "Reverse Polarity"...........Keep in mind that reverse polarity makes the chassis hot. When I reached up to grab the bumper (my knees and one hand still on the ground) I got the shit knocked out of me.
Hang in there
Harry Babb
Bruce did a much better job of expaining the detail than I did.....just follow his instructions.
About 25 years ago a friend asked me to install a trailer hitch on his motor home. I went to his house early one morning to look at the situation. Well.......he had the power cord (Shore Power) pluged into a receptical that was wired up for "Reverse Polarity"...........Keep in mind that reverse polarity makes the chassis hot. When I reached up to grab the bumper (my knees and one hand still on the ground) I got the shit knocked out of me.
Hang in there
Harry Babb
hb
Following instructions heres what I found.
Green to Black on the meter got 89.5 v
Green to white on the meter got 38.4 v
Heres the catch, today the reverse polarity light did not come on.
(generator has seen some hard use and probably no maintenence......it spends a lot of time on a tug and barge so salt spray may have got into outlets. I am just guesing at this point to the reverse polarity problem)
The raw water circulation pump works fine, draws about 2 amps or less.
The blower works fine also. The Honda will run both in ECONO mode.
Try to start compressor and at best it sounds like it is trying to start some of the time but the gen really revs up and then power is lost after about 3 seconds and it idles down even if not in econo mode. Gen must be shut off and re-started to get power back.
Green to Black on the meter got 89.5 v
Green to white on the meter got 38.4 v
Heres the catch, today the reverse polarity light did not come on.
(generator has seen some hard use and probably no maintenence......it spends a lot of time on a tug and barge so salt spray may have got into outlets. I am just guesing at this point to the reverse polarity problem)
The raw water circulation pump works fine, draws about 2 amps or less.
The blower works fine also. The Honda will run both in ECONO mode.
Try to start compressor and at best it sounds like it is trying to start some of the time but the gen really revs up and then power is lost after about 3 seconds and it idles down even if not in econo mode. Gen must be shut off and re-started to get power back.
Check with your dealer to see if a factory kit is available for your model. if not a good AC guy could probably put one together for you. I just replace the starting capacitor on the heat pump on my house and it was a $28.00 part. The trick is getting the right size for your unit and how to wire it in. I'm sure Bruce will chime in with more details.
Rawleigh
1966 FBC 31
1966 FBC 31
Kevin: Have you tried starting the compressor with the EU2000i in regular mode? I think it is going to have to be reved up to have the instantaneous starting load the a/c requires. If I turn everything else off, mine will start my 12000 btu unit, but not like when it is plugged into shore power. I have an older unit with reciprocating compressor that takes more juice to start than the newer rotary compressors. I made up a separate cord with a 15 amp male on one end and a 30 amp female on the other just long enough to go from the generator to my power inlet. I used heavy three conductor wire to lessen the losses.
Eddy G.
Eddy G.
Eddy,
Tried both ways a few times and got the same result. In regular mode it still revs up higher when you juice the compressor and will fail after a few seconds if you do not back off. This AC worked great a year ago on 30 amp shore power. At this point everything is sort of new as far as my electrical work and trying the honda on the 12000 btu AC. I wonder if these old compressors get sticky like a compressor on a car. Tried tapping top of it with hammer but still no go. Is there a magnet in these things like on a car? Tapped with hammer and tried to start but still over loaded gen.
Tried both ways a few times and got the same result. In regular mode it still revs up higher when you juice the compressor and will fail after a few seconds if you do not back off. This AC worked great a year ago on 30 amp shore power. At this point everything is sort of new as far as my electrical work and trying the honda on the 12000 btu AC. I wonder if these old compressors get sticky like a compressor on a car. Tried tapping top of it with hammer but still no go. Is there a magnet in these things like on a car? Tapped with hammer and tried to start but still over loaded gen.
Assuming you are using the same extention cord for the shed power and the gen set, you've got some sort of internal problem in the gen set. Probably the gen set neutral wire is faulty...i.e. corroded or partially broken, or bad connection.Following instructions heres what I found.
Green to Black on the meter got 89.5 v
Green to white on the meter got 38.4 v
Black is "hot"
White is "neutral" which eventually finds its way back to ground
Green is "ground"
The difference between "ground" and "neutral" is that the neutral wire is meant to carry current when something is in use, and the ground wire is only there to carry current if something is shorted to it. (like a loose wire touching a metal case. If the case is gounded as it should be, the current is carried safely away by the green ground wire.)
You shouldn't see any voltage across white to green (neutral to ground)
Peter
Peter is correct and the voltage is way low.
Economy mode only drops rpm down to save fuel on lite loads but retains proper voltage.
Induction type of loads such as compressors trying to start on low voltage makes the amps spike and drops the voltage even farther because the load won't start.
You can ruin a compressor real easily trying to start on low voltage.
Stop what your doing till you can get a good 115 to 120 voltage.
Put the meter into the second gen outlet to monitor the voltage when trying to start the AC.
If it dips below 100 volts, stop trying to use the gen set.
Economy mode only drops rpm down to save fuel on lite loads but retains proper voltage.
Induction type of loads such as compressors trying to start on low voltage makes the amps spike and drops the voltage even farther because the load won't start.
You can ruin a compressor real easily trying to start on low voltage.
Stop what your doing till you can get a good 115 to 120 voltage.
Put the meter into the second gen outlet to monitor the voltage when trying to start the AC.
If it dips below 100 volts, stop trying to use the gen set.
Now that I think of it, the multi meter on the panel read about 127ish which is about the sum of the the readings taken with the handheld meter. Does kind of sound like it may be the gen set. Sometimes my curiousity and persistence gets expensive though, tried to get that compressor going 8-10 times before going to work on tuesday......before being advised not to try it in the latest post. Wonder how much a compressor costs. I should have known better.
Should I call Marine Air in lauderdale and get a hard start kit or is this something I can get locally?
Will check the output at the receptical on the genset in the morning, which is approaching fast on my schedule. Probably take a close look at the gen set receptacles ifor corrosion f they are accesible from the back. Never a dull moment in the world of boating! On the bright side it is almost paid off, engines and all!!!! Thanks for all the education on this stuff.
Should I call Marine Air in lauderdale and get a hard start kit or is this something I can get locally?
Will check the output at the receptical on the genset in the morning, which is approaching fast on my schedule. Probably take a close look at the gen set receptacles ifor corrosion f they are accesible from the back. Never a dull moment in the world of boating! On the bright side it is almost paid off, engines and all!!!! Thanks for all the education on this stuff.
Very astute of you.Now that I think of it, the multi meter on the panel read about 127ish which is about the sum of the the readings taken with the handheld meter.
The sum of the individual voltage drops accross each load wired in series througout the entire circuit has to equal the total voltage from the source when the circuit is open.
So you are dropping some of your votage where you should be...that is across the load on the boat.....but you are also dropping the remainder of your voltage where you shouldn't be...that is between the neutral wire and where the neutral wire attaches to the ground wire. Its like someone put a big resistor in the middle of the white wire before it got back to the ground connection.
If the neutral wire were in good shape it would have near to zero impedance and so there would be no voltage drop between white and ground, making the the total voltage drop occur only across the load at the boat. Just like the shed power reading.
The voltage drop on the neutal to ground is roughly 1/2 of that from hot to ground so the impedance in the neutral wire is about half of the impedance of the load at the boat. That is a significant amout.
Look for a big resistance (or in AC we say impedance) between where the neutral wire exits your load at the boat and where it ultimately connects with the ground.
As a result of the additional impedance in the neutral path the total impedance of your circuit is so high that it is seriously limiting the current available to start your compressor. And current is the limiting factor in starting a motor.
Peter
Peter,
Think I get the jist of what you are saying, but things are still a little fuzy.
Something else I neglected to mention, may or may not be of importance, but I will explain. Utilizing "cord from outlet at the shed" I have a true ground since somewhere we assume the outlet connects to earth. With the generator, there is no actual ground or safety ground. I forgot to connect my DC ground on the panel to the AC safety ground "green." Now that I am trying to run true loads through the new panel I am guessing that was not so bright of me.
Also trying to get manual for the Marine Air but waiting on a call back. I bet the thing is 20 years old based on what it weighs.
Think I get the jist of what you are saying, but things are still a little fuzy.
Something else I neglected to mention, may or may not be of importance, but I will explain. Utilizing "cord from outlet at the shed" I have a true ground since somewhere we assume the outlet connects to earth. With the generator, there is no actual ground or safety ground. I forgot to connect my DC ground on the panel to the AC safety ground "green." Now that I am trying to run true loads through the new panel I am guessing that was not so bright of me.
Also trying to get manual for the Marine Air but waiting on a call back. I bet the thing is 20 years old based on what it weighs.
Kevin,
I hate to confuse your thinking even more--- but here goes. A majority of small generators are split phased. (one's that only put out 120v not 220v) So I feel your voltage measurments are correct. On household current you have no potential (voltage) between your ground and your neutral.
But on your generator you have voltage between the 2 and have aprox. 120v measured between L1 and Neutral. All good and normal so far.
But because of this split phase, the neutral must always be above the ground and not bonded togather anywhere or you will have major voltage drop.
Your AC may have a bonded neutral or possibly your sub panel causing reduced voltage to the unit. As Bruce stated earlier connect with a good source (big wire/ short run) before you start condeming anything or piling on capacitors.
Good luck
Ray
I hate to confuse your thinking even more--- but here goes. A majority of small generators are split phased. (one's that only put out 120v not 220v) So I feel your voltage measurments are correct. On household current you have no potential (voltage) between your ground and your neutral.
But on your generator you have voltage between the 2 and have aprox. 120v measured between L1 and Neutral. All good and normal so far.
But because of this split phase, the neutral must always be above the ground and not bonded togather anywhere or you will have major voltage drop.
Your AC may have a bonded neutral or possibly your sub panel causing reduced voltage to the unit. As Bruce stated earlier connect with a good source (big wire/ short run) before you start condeming anything or piling on capacitors.
Good luck
Ray
Wow, it is becoming clear that the more I learn about this the more I need to learn.
I did try a two foot section of heavy cord directly from gen to boat receptical. The wire from the receptaccle in the cockpit to the panel is brand new three wire less than eight feet in length. Installed it myself. Followed instructions with panel and put the green, white and black to there perspective bars. The built in multi-meter on the panel gives me amps, hertz?, voltage and watts I think is the other reading. All readings appear to be normal on the panel and jive with the hand held VOM on the Gen. Have not had the reverse polarity light come back on since the other day. I tested the recepticals on the gen directly with the hand held VOM and it read 125ish. I should be recieving a PDF file today or tomorrow of the manual for the Air Conditoiner. I wish I had access to a 30amp legit shore power. Getting more comfortable with a VOM every time I stick the leads somewhere I think they should not be stuck. Very interesting subject matter to me and it is great to have the support from the crew here.
I did try a two foot section of heavy cord directly from gen to boat receptical. The wire from the receptaccle in the cockpit to the panel is brand new three wire less than eight feet in length. Installed it myself. Followed instructions with panel and put the green, white and black to there perspective bars. The built in multi-meter on the panel gives me amps, hertz?, voltage and watts I think is the other reading. All readings appear to be normal on the panel and jive with the hand held VOM on the Gen. Have not had the reverse polarity light come back on since the other day. I tested the recepticals on the gen directly with the hand held VOM and it read 125ish. I should be recieving a PDF file today or tomorrow of the manual for the Air Conditoiner. I wish I had access to a 30amp legit shore power. Getting more comfortable with a VOM every time I stick the leads somewhere I think they should not be stuck. Very interesting subject matter to me and it is great to have the support from the crew here.
- In Memory of Vicroy
- Senior Member
- Posts: 2340
- Joined: Jun 29th, '06, 09:19
- Location: Baton Rouge, LA
- In Memory of Vicroy
- Senior Member
- Posts: 2340
- Joined: Jun 29th, '06, 09:19
- Location: Baton Rouge, LA
You apparently have a fault (short) between the load side and the ground, may be just some salt buildup on a circuit board. The CX will get rid of it in a few hours, just shoot it good and let it sit.
Another important issue with gensets is to try to establish a separate ground via a ground rod vs. relying on the genset's ground. If you can, drive a ground rod near the genset and run a heavy wire from the genset ground to it.....or a cold water pipe will usually do. A good separate ground will greatly increase the "oomph" of a genset, not to mention enhance the safety. For example, on my 21KW diesel home standby unit I drove a 10' copper clad ground rod near it and connected the genset ground (in my case, a big green lug inside the electrical end) with some #4 stranded wire to it via a copper clamp. So I'm not relying on the house ground, who knows where it is?
On our boats, we don't have ground rods, but we have our bonding systems and dynaplates which work pretty good. On AJ I have two dynaplates and use one for the SSB ground system to terminate into and the other for the 12V and genset. The genset ground is tied to the 12v negative battery side - a couple of 8-D batteries make a pretty good ground in themselves, like real big capacitors. I'd prefer to have a 3d dynaplate for the genset but you gotta stop somewhere.
An area we all need to know a lot about.....I tried to explain three phase pwoer to someone once and ran out of hands.....
UV
Another important issue with gensets is to try to establish a separate ground via a ground rod vs. relying on the genset's ground. If you can, drive a ground rod near the genset and run a heavy wire from the genset ground to it.....or a cold water pipe will usually do. A good separate ground will greatly increase the "oomph" of a genset, not to mention enhance the safety. For example, on my 21KW diesel home standby unit I drove a 10' copper clad ground rod near it and connected the genset ground (in my case, a big green lug inside the electrical end) with some #4 stranded wire to it via a copper clamp. So I'm not relying on the house ground, who knows where it is?
On our boats, we don't have ground rods, but we have our bonding systems and dynaplates which work pretty good. On AJ I have two dynaplates and use one for the SSB ground system to terminate into and the other for the 12V and genset. The genset ground is tied to the 12v negative battery side - a couple of 8-D batteries make a pretty good ground in themselves, like real big capacitors. I'd prefer to have a 3d dynaplate for the genset but you gotta stop somewhere.
An area we all need to know a lot about.....I tried to explain three phase pwoer to someone once and ran out of hands.....
UV
With a portable generator that's not grounded, there will not be a pontential to measure to with a meter, except back to itself. A meter reading to anything except itself will be a floating measurement, of no value. Once you hook it to your home or other grounded system, the neutral will be referenced to earth ground and your meter will measure to any ground, not just back to the generator. I'm not sure if Kevin's boat is referenced to earth ground or not, and from the posts I've read, I wouldn't dare venture a guess of the problem. UV, I'm not sure if all generator neutrals are grounded to there case(equipment ground). If yours is not, you may only have a #4 equipment ground (not a bad thing). On the other hand, your neutral should only be grounded at one point, usually at the meter base, so unless the home ground is bad (if so, you would want to fix it) I think the second ground is redundant, but I don't think is a problem either.
ScottD
ScottD
- In Memory of Vicroy
- Senior Member
- Posts: 2340
- Joined: Jun 29th, '06, 09:19
- Location: Baton Rouge, LA
No, the genset ground on the 21KW is a separate ground from the 3 wire 240 VAC, and that's what I'm referring to...The two hots (blacks, some may be a black and a red) and the one neutral (white) are grounded normally thru the house ground. My rule is to have a separate ground rod for the green "hard" ground from the genset, not just the frame, but in the inside of the electrical end where you will always find a "green" ground point to hook a hard ground to. Makes the genset work a lot better to hard ground it to a rod. Sort of like ground planing a SSB, a "kick point". Since the white is always going to a ground like the green, the house ground is always suspect vs. using a separate rod for the genset.
Guess I made it harder than it is.
UV
Guess I made it harder than it is.
UV
First off;
UV, You blow me away. You have total grasp on the situation, and CX is probably going to be the best answer.
All voltage is relative. Like water pressure it is the measure of the difference in electromotive force between one spot and another.
In the system where the boat is hooked up to the gen set you may or may not have a path to ground depending on how the AC circuitry is set up on your boat. Neutral on the boat shouldn't be connected to the bonding system, but the ground wire might be. In the case of the test you did it doesn't matter.
Take the case where the ground is floating at some voltage above the "real" ground of the shed system (which is somewhere attached to a big stake in the earth.) What does this mean to the voltage reading you took in your test?
The voltage between the black and white gen set wires (load to neutral) should still be at 120 Vots or so.The generator doesn't care that its ground isn't the same as earth. It just generates voltage relative to its own ground. Since your meter is reading 127V for the shed, your meter should be expected to read about the same for the gen set arrangement.. that is if everything were working well. i.e. since neutral is generally at the ground potential your meter should still read something like 127V between the gen set load and the gen set ground.
In your case it doesn't....but as I posted earlier, the sum of the voltage drops HAS to add up to the total open circuit voltage.... and in your case this is true. In the accounting of the two voltage drops you found the sum to be very close to the expected open circuit voltage. This means there are no other loads or floating voltages to account for. Just the one of the boat, and the one which has shown up in the neutral side of the gen set somehow.
Look at it another way. If the "ground" of the gen set arrangement were 20 volts above "real" ground then the voltage measured between gen set load and gen set ground would still register as 127 on your meter, even though the measurement between gen set load and "real" ground would be 147. If things were working right the measurement between gen set neutral and gen set ground would still be 0, even though the same measurement referenced to "real" ground would be 20.
Even though this is an over sipmlification you should get the concept. Actually if the gen set ground floats up to a higher voltage that isn't alternating current you get what is called a DC offset,which you won't be able to read with your meter but it all shouldn't matter within the reference frame of the gen set system
Now Ray wrote that most small generators are "split phase." I don't work on generators so I am no expert on the particulars of how they are set up. But split phase generally refers to the way electricity is delivered to homes in North America. There are actually 4 wires: two load lines (L1 and L2), one neutral and the ground.
L1 oscillates between -120 volts and +120 volts with respect to neutral 60 times a second. Hook your meter between this and the neutral wire and you read 120 volts AC. ...... L2 does the same thing but just at the moment the L1 is at +120, L2 is at -120 or 180 degrees out of phase. Hook your meter between L1 and L2 and you will read 240 volts. Remember Voltage is relative so +120 to -120 is 240. That is how in North America we get to have some 120 volt appliances and some 240 Volt appliances.
Ray, when you say the small gen sets run on split phase do you mean that "neutral" is really L2 and that each leg is -/+60 Volts at a 180 degree phase angle making 120 Volts between them? That certainly would work for running a hedge clipper or small power tool,but if someone wanted to use one of these to run a small building would he then have to re-wire the panel in the building to separate the building neutral and ground?
If that is what you are saying, then there must be no connection from the "Neutral" or L2 or whatever you want to call the white wire in this case, and the ground anywhere for this system to work...Which is I believe what you said. If there were a path between white and ground then white would short out to ground, lowereing its voltage to 0 and the reading across the black to ground would be around 60 volts??? Am I on the right track here?
Educate us.!! I'm curious.
Peter
UV, You blow me away. You have total grasp on the situation, and CX is probably going to be the best answer.
All voltage is relative. Like water pressure it is the measure of the difference in electromotive force between one spot and another.
In the system where the boat is hooked up to the gen set you may or may not have a path to ground depending on how the AC circuitry is set up on your boat. Neutral on the boat shouldn't be connected to the bonding system, but the ground wire might be. In the case of the test you did it doesn't matter.
Take the case where the ground is floating at some voltage above the "real" ground of the shed system (which is somewhere attached to a big stake in the earth.) What does this mean to the voltage reading you took in your test?
The voltage between the black and white gen set wires (load to neutral) should still be at 120 Vots or so.The generator doesn't care that its ground isn't the same as earth. It just generates voltage relative to its own ground. Since your meter is reading 127V for the shed, your meter should be expected to read about the same for the gen set arrangement.. that is if everything were working well. i.e. since neutral is generally at the ground potential your meter should still read something like 127V between the gen set load and the gen set ground.
In your case it doesn't....but as I posted earlier, the sum of the voltage drops HAS to add up to the total open circuit voltage.... and in your case this is true. In the accounting of the two voltage drops you found the sum to be very close to the expected open circuit voltage. This means there are no other loads or floating voltages to account for. Just the one of the boat, and the one which has shown up in the neutral side of the gen set somehow.
Look at it another way. If the "ground" of the gen set arrangement were 20 volts above "real" ground then the voltage measured between gen set load and gen set ground would still register as 127 on your meter, even though the measurement between gen set load and "real" ground would be 147. If things were working right the measurement between gen set neutral and gen set ground would still be 0, even though the same measurement referenced to "real" ground would be 20.
Even though this is an over sipmlification you should get the concept. Actually if the gen set ground floats up to a higher voltage that isn't alternating current you get what is called a DC offset,which you won't be able to read with your meter but it all shouldn't matter within the reference frame of the gen set system
Now Ray wrote that most small generators are "split phase." I don't work on generators so I am no expert on the particulars of how they are set up. But split phase generally refers to the way electricity is delivered to homes in North America. There are actually 4 wires: two load lines (L1 and L2), one neutral and the ground.
L1 oscillates between -120 volts and +120 volts with respect to neutral 60 times a second. Hook your meter between this and the neutral wire and you read 120 volts AC. ...... L2 does the same thing but just at the moment the L1 is at +120, L2 is at -120 or 180 degrees out of phase. Hook your meter between L1 and L2 and you will read 240 volts. Remember Voltage is relative so +120 to -120 is 240. That is how in North America we get to have some 120 volt appliances and some 240 Volt appliances.
Ray, when you say the small gen sets run on split phase do you mean that "neutral" is really L2 and that each leg is -/+60 Volts at a 180 degree phase angle making 120 Volts between them? That certainly would work for running a hedge clipper or small power tool,but if someone wanted to use one of these to run a small building would he then have to re-wire the panel in the building to separate the building neutral and ground?
If that is what you are saying, then there must be no connection from the "Neutral" or L2 or whatever you want to call the white wire in this case, and the ground anywhere for this system to work...Which is I believe what you said. If there were a path between white and ground then white would short out to ground, lowereing its voltage to 0 and the reading across the black to ground would be around 60 volts??? Am I on the right track here?
Educate us.!! I'm curious.
Peter
It's 3 AM, just got home from work. I kinda thought this topic might get really interesting. I did blast the gen with CX red and I am going to do it again later with copious amounts to clean out the recepticals. As for all the L1 and L2, phases, flux capacitors I am mentally about to short cicuit, but nevertheless this is good stuff. It makes CD players, amplifiers and speakers look so much easier in perspective. That stuff I did first. gotta have tunes. Red and black.........so easy a caveman could do it. Just think, I still have to hook up the fridge, outlets, head pump, navlights, water pump, trim tabs, navigation electronics, lighting and much more. you guys are gonna get tired of my electrical questions.
Peter,
Ray, when you say the small gen sets run on split phase do you mean that "neutral" is really L2 and that each leg is -/+60 Volts at a 180 degree phase angle making 120 Volts between them? That certainly would work for running a hedge clipper or small power tool,but if someone wanted to use one of these to run a small building would he then have to re-wire the panel in the building to separate the building neutral and ground?
If that is what you are saying, then there must be no connection from the "Neutral" or L2 or whatever you want to call the white wire in this case, and the ground anywhere for this system to work...Which is I believe what you said. If there were a path between white and ground then white would short out to ground, lowereing its voltage to 0 and the reading across the black to ground would be around 60 volts??? Am I on the right track here?
[/quote]
That is correct. On some smaller gensets 120 V is measured between the blk. & Wh wires, not to ground. If your panel neutral is bonded to ground it will short that voltage to ground. People backfeeding small generators to their house encounter this problem and backfeed 60v to the neutral which is unfused/unswitched at the panel.
The way I found this out is by wiring up a Mardi Gras bus a few years ago. We switched from a 220V genset (where voltage was the same as household current) to a smaller 120V genset.... then nothing on the bus would work and the girls couldn't pole dance.
According to the NEC -The service entrance is the only place the neutral and ground are bonded. On sub panels the neutral floats above the ground.
Clear as mud?
Ray
Ray, when you say the small gen sets run on split phase do you mean that "neutral" is really L2 and that each leg is -/+60 Volts at a 180 degree phase angle making 120 Volts between them? That certainly would work for running a hedge clipper or small power tool,but if someone wanted to use one of these to run a small building would he then have to re-wire the panel in the building to separate the building neutral and ground?
If that is what you are saying, then there must be no connection from the "Neutral" or L2 or whatever you want to call the white wire in this case, and the ground anywhere for this system to work...Which is I believe what you said. If there were a path between white and ground then white would short out to ground, lowereing its voltage to 0 and the reading across the black to ground would be around 60 volts??? Am I on the right track here?
[/quote]
That is correct. On some smaller gensets 120 V is measured between the blk. & Wh wires, not to ground. If your panel neutral is bonded to ground it will short that voltage to ground. People backfeeding small generators to their house encounter this problem and backfeed 60v to the neutral which is unfused/unswitched at the panel.
The way I found this out is by wiring up a Mardi Gras bus a few years ago. We switched from a 220V genset (where voltage was the same as household current) to a smaller 120V genset.... then nothing on the bus would work and the girls couldn't pole dance.
According to the NEC -The service entrance is the only place the neutral and ground are bonded. On sub panels the neutral floats above the ground.
Clear as mud?
Ray
Ray...
Really? No Kidding? I never would have guessed, .... and I suppose you wouldn't have either except that you found out the hard way.
Ya live, ya learn...
I'd have to look, but I'm pretty sure my house isn't wired like that. But then I have a 220v generator so I guess it wouldn't matter.
Peter
Really? No Kidding? I never would have guessed, .... and I suppose you wouldn't have either except that you found out the hard way.
Ya live, ya learn...
So if I'm getting this the netral from the house only gets bonded to the ground at a point before the master switch in the main panel...and then if you shut the main off while using a transfer panel to run off a generator the neutral is floating??According to the NEC -The service entrance is the only place the neutral and ground are bonded. On sub panels the neutral floats above the ground.
I'd have to look, but I'm pretty sure my house isn't wired like that. But then I have a 220v generator so I guess it wouldn't matter.
Peter
- In Memory of Vicroy
- Senior Member
- Posts: 2340
- Joined: Jun 29th, '06, 09:19
- Location: Baton Rouge, LA
Bottom line for my setup.
Generator is good. Think some salt might have been the culprit with receptacle. Never had another reverse polarity isseue.
Got the manual for the Marine Air. Despite being a mid 80's model apparently there is some sort of hard start capacitor in it. Took the cover plate off and looks like a coil from a old distributor type pushrod motor.
There are two sources of 115 voltage for the whole system. One is hard wired from the panel and the other looks like a normal cord coming out of what I will assume is the capacitor (thing that looks like a coil) but does not have male plug at the end.....instead it is a female plug. Adapted it to another breaker on the panel. Wired the raw water pump to another breaker to isolate everything. Still no go with starting the compressor.
I will not be installing permanent genset so the plan is to modernize the air conditioner with a new one that WILL run off the Honda 2000. That however is still undetermined because getting a concrete answer on what size modern AC unit will have acceptable start up load for a Honda 2000 is tough.
Based on cabin space I need between 10 and 12K BTU. If any of you guys have modern air conditioners of that size and have run it off the Honda I would love to hear about it. I will base what I purchase based on tried and proven wisdom from the faithful. Again, thanks for all the brain teasing, I "think" I have learned a lot.
Generator is good. Think some salt might have been the culprit with receptacle. Never had another reverse polarity isseue.
Got the manual for the Marine Air. Despite being a mid 80's model apparently there is some sort of hard start capacitor in it. Took the cover plate off and looks like a coil from a old distributor type pushrod motor.
There are two sources of 115 voltage for the whole system. One is hard wired from the panel and the other looks like a normal cord coming out of what I will assume is the capacitor (thing that looks like a coil) but does not have male plug at the end.....instead it is a female plug. Adapted it to another breaker on the panel. Wired the raw water pump to another breaker to isolate everything. Still no go with starting the compressor.
I will not be installing permanent genset so the plan is to modernize the air conditioner with a new one that WILL run off the Honda 2000. That however is still undetermined because getting a concrete answer on what size modern AC unit will have acceptable start up load for a Honda 2000 is tough.
Based on cabin space I need between 10 and 12K BTU. If any of you guys have modern air conditioners of that size and have run it off the Honda I would love to hear about it. I will base what I purchase based on tried and proven wisdom from the faithful. Again, thanks for all the brain teasing, I "think" I have learned a lot.
- In Memory of Vicroy
- Senior Member
- Posts: 2340
- Joined: Jun 29th, '06, 09:19
- Location: Baton Rouge, LA
Keven, don't guess, get a clamp on ampmeter and test what the existing unit draws in plain ole amps. You will need to clamp it over just one leg (either the black or the white, but not both) for it to work. See what draw you are getting when you turn it on from the genset. A single lung gas 2KW is on the light side to start a 12K a/c unit, even with a hard start big capacitor. Your little Honda only puts out 16.7 amps at 120v if its working at it's best, and I suspect you will find that the start amps on the a/c is more than that.....the little single lung gen just does not have the flywheel weight to carry it through the surge of a hard start. I have to stage in my 3 central a/c systems to start one at a time on my 21 KW with a 4 cyl Kubota diesel driving it....it will bog down if I try to let them all start at once. On the other hand, the 6.5 KW Phasor on AJ (3 cyl. Kubota diesel) will kick the 12K Cruisare on without a hickup....power, my friend, you need more power.
UV
UV
Peter,
Even though the ground and neutral are bonded at the service entrance, the neutral floats (or stays seperate) above the ground thru the rest of the system.
The reason being that if you damage, cut or have a bad connetion on your neutral- your tool, appliance or what ever will not work. BUT If your ground and neutral are bonded downstream of your damaged neutral then your EGC (equipment grounding conductor) will be carrying current and have potential to earth ground. It could be a tingle or it could be death, depends how good the equipment grounding path is. So that metal case of that Sawzall or any tool with a 3 prong plug will have a different potential to earth and a shock hazard.
Unlikely? Yes. Possible? Yes.
Kevin,
Back to your AC problem. Most Ref. guys have equip. that can free up a motor by trying to reverse it or give it a jolt. For my money I would give that a try and use shore power 1st until you have an operating system before I would bring the generator into the mix. Then you could measure your run current and start crank amps to be sure the generator will handle them. I assume the generator will handle the load, but I like to troubleshoot 1 system at a time.
Good luck
Ray
You can never make something foolproof because fools are so ingenious.
Pretty much correct. As Scott stated-- the neutral and ground are never switched or fused.So if I'm getting this the netral from the house only gets bonded to the ground at a point before the master switch in the main panel...and then if you shut the main off while using a transfer panel to run off a generator the neutral is floating??
I'd have to look, but I'm pretty sure my house isn't wired like that. But then I have a 220v generator so I guess it wouldn't matter.
Even though the ground and neutral are bonded at the service entrance, the neutral floats (or stays seperate) above the ground thru the rest of the system.
The reason being that if you damage, cut or have a bad connetion on your neutral- your tool, appliance or what ever will not work. BUT If your ground and neutral are bonded downstream of your damaged neutral then your EGC (equipment grounding conductor) will be carrying current and have potential to earth ground. It could be a tingle or it could be death, depends how good the equipment grounding path is. So that metal case of that Sawzall or any tool with a 3 prong plug will have a different potential to earth and a shock hazard.
Unlikely? Yes. Possible? Yes.
Kevin,
Back to your AC problem. Most Ref. guys have equip. that can free up a motor by trying to reverse it or give it a jolt. For my money I would give that a try and use shore power 1st until you have an operating system before I would bring the generator into the mix. Then you could measure your run current and start crank amps to be sure the generator will handle them. I assume the generator will handle the load, but I like to troubleshoot 1 system at a time.
Good luck
Ray
You can never make something foolproof because fools are so ingenious.
- AndreF
- Senior Member
- Posts: 711
- Joined: Jun 29th, '06, 09:53
- Location: Baton Rouge, Louisiana
- Contact:
Kevin,
I started to tell you that at the beginning of this thread................
I got a headache reading it all
I started to tell you that at the beginning of this thread................
I got a headache reading it all
I'm not sure but indecision may or may not be my problem.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell
1981 FBC BERG1883M81E
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell
1981 FBC BERG1883M81E
- Dave Kosh R.I.P.
- Senior Member
- Posts: 162
- Joined: Jun 30th, '06, 00:10
- Location: Ft. Myers Beach, FL 33931
- Contact:
Kevin, 10-1 it is simply some salt water corrosion on the inside of the genset output receptacle or leading to it. Only problem with operating that little generator outside in the salt spray is you know what. Corrosion X will fix it if disassembled and clean up. If I was closer I would do it for you. Keep following the above instructions from the board and you will find it. Just be careful when working with hot AC current. Did the Air work before on the genset? If so it already has a stating capacitor probably. Get the Generator working with the proper voltages before you do anything else. Dave K
Keep Fishing...
Kevin,
Go back and search the original threads about the 2000. It will start a 12k btu ac no problem.
But it has to be working properly.
While I have been tempted in the past to lock threads for misinformation, I never did.
But this thread makes my head hurt.
If you have any more electrical questions, you can start a new thread.
Go back and search the original threads about the 2000. It will start a 12k btu ac no problem.
But it has to be working properly.
While I have been tempted in the past to lock threads for misinformation, I never did.
But this thread makes my head hurt.
If you have any more electrical questions, you can start a new thread.
Who is online
Users browsing this forum: Bing [Bot] and 86 guests