Inverter Question...... Got me confused!

[MnTom-FRF]

Hey everyone, I recently acquired a 3500w inverter (Edecoa 3500) that I was thinking about using for some boon docking. I have 400ah of FLA batteries (for now) and hooked up the inverter. I plugged my trailer in and the surge protector (Progressive Industries 35550 hard wired) won't let the power go to the trailer. I checked the output of the inverter and here is where I run into an issue. Between hot and neutral I see 121.7vac, but from hot to ground I see 88vac, and neutral to ground I see 74vac. The surge protector won't allow the power to the RV because of the neutral-ground voltage I am guessing. Also, the inverter has a floating neutral, so I tried a neutral-ground bonding connection. That makes the inverter throw an overload alarm and no voltage is created, so, it appears that is not what the problem is. However, I have a 3600w inverter generator that has a floating neutral and with a neutral-ground bond it powers the RV just fine through the surge protector. I have tried emailing both Edecoa and Progressive Industries, but they don't seem to want to reply to me......

 

[TitanMike]

Hey everyone, I recently acquired a 3500w inverter (Edecoa 3500) that I was thinking about using for some boon docking. I have 400ah of FLA batteries (for now) and hooked up the inverter. I plugged my trailer in and the surge protector (Progressive Industries 35550 hard wired) won't let the power go to the trailer. I checked the output of the inverter and here is where I run into an issue. Between hot and neutral I see 121.7vac, but from hot to ground I see 88vac, and neutral to ground I see 74vac. The surge protector won't allow the power to the RV because of the neutral-ground voltage I am guessing. Also, the inverter has a floating neutral, so I tried a neutral-ground bonding connection. That makes the inverter throw an overload alarm and no voltage is created, so, it appears that is not what the problem is. However, I have a 3600w inverter generator that has a floating neutral and with a neutral-ground bond it powers the RV just fine through the surge protector. I have tried emailing both Edecoa and Progressive Industries, but they don't seem to want to reply to me......

Same happened to me. Couldn't power anything from the inverter that required a neutral/ground bond.

I have had zero issues just plugging shore power cord into inverter power without an EMS or Surge Protector. Controls within the inverter protect against low voltage, they just shut down.

 

[Reverse_snowbird]

I plugged my trailer in and the surge protector (Progressive Industries 35550 hard wired) won't let the power go to the trailer.
However, I have a 3600w inverter generator that has a floating neutral and with a neutral-ground bond it powers the RV just fine through the surge protector. .

Hmmmm.....
Where are you plugged into... the house or a campsite?
You're getting power from the generator, but not the other source.
Usually, surge protectors don't allow electricity to pass through to the trailer if there is a problem at the source.

 

[rk06382]

Hey everyone, I recently acquired a 3500w inverter (Edecoa 3500) that I was thinking about using for some boon docking. I have 400ah of FLA batteries (for now) and hooked up the inverter. I plugged my trailer in and the surge protector (Progressive Industries 35550 hard wired) won't let the power go to the trailer. I checked the output of the inverter and here is where I run into an issue. Between hot and neutral I see 121.7vac, but from hot to ground I see 88vac, and neutral to ground I see 74vac. The surge protector won't allow the power to the RV because of the neutral-ground voltage I am guessing. Also, the inverter has a floating neutral, so I tried a neutral-ground bonding connection. That makes the inverter throw an overload alarm and no voltage is created, so, it appears that is not what the problem is. However, I have a 3600w inverter generator that has a floating neutral and with a neutral-ground bond it powers the RV just fine through the surge protector. I have tried emailing both Edecoa and Progressive Industries, but they don't seem to want to reply to me......

Is the inverter UL-certified?

UL-certified inverters currently fall under two certification codes: UL458 and UL1741.

NEC and UL 458, is for use in an RV with a neutral-ground bonding connection.


My Samlex EVO-3012 Inverter/Charger is both UL458 and UL1741 certified.

 

[Aussieguy]

what Titan said... ditch the EMS
you only really need it because of outside power

you are the power company...
keep your equipment in good condition and avoid performing any maintenance while inverter power is ON you should then be good without a EMS

 

[MnTom-FRF]

what Titan said... ditch the EMS
you only really need it because of outside power

you are the power company...
keep your equipment in good condition and avoid performing any maintenance while inverter power is ON you should then be good without a EMS

The only problem I have is trying to come up with a way to wire it to work. The inverter only has one hot line, but my trailer takes two. If I wire the two lines together I won't be able to use the 50A that the trailer is set up for. That is why I want to use what I have so there would be zero chance of trying to power the trailer from two sources at the same time and be safe.

 

[TitanMike]

The only problem I have is trying to come up with a way to wire it to work. The inverter only has one hot line, but my trailer takes two. If I wire the two lines together I won't be able to use the 50A that the trailer is set up for. That is why I want to use what I have so there would be zero chance of trying to power the trailer from two sources at the same time and be safe.

An old but effective way to achieve what I think you want would be go back to the old school transfer switch which was just two separate receptacles next to each other.

One was wired to the shore power source and the other to the generator ( or in your case the Inverter).

Use a NEMA 14-50R for the receptacles. Wire one to shore power FROM THE EMS output (wires to power distribution panel disconnected), and the one from inverter with Inverter neutral connected to receptacle neutral and the hot from inverter to L-1 and L-2. ( a jumper). Each receptacle is now connected to separate power sources but NOT to the load Power distribution panel.

Now add a NEMA 14-50P to line going to power distribution panel (wires disconnected from EMS output.

When shore power is desired plug into receptacle marked "Shore Power" and for inverter move plug to receptacle marked "Inverter".

No moving parts other than the single plug.

A lot if generator equipped RV's came from the factory wired this way before auto transfer switches became more affordable and before the EMS arrived on the scene.

 

[MnTom-FRF]

TitanMike, That would be the easiest and least complicated way to make it work, but the voltage on the neutral line and no neutral/ground bond creates an potentially unsafe condition in my mind. There is where I get concerned.

 

[TitanMike]

TitanMike, That would be the easiest and least complicated way to make it work, but the voltage on the neutral line and no neutral/ground bond creates an potentially unsafe condition in my mind. There is where I get concerned.

Is it a problem when just plugged directly into the generator using a dog bone? Never has been an issue with my generator.

RV's generally don't have bonded neutral/ground unless plugged into shore power where neutral is ground bonded at the main panel providing shore power.

 

[MnTom-FRF]

Is it a problem when just plugged directly into the generator using a dog bone? Never has been an issue with my generator.

RV's generally don't have bonded neutral/ground unless plugged into shore power where neutral is ground bonded at the main panel providing shore power.

I do believe NEC requires a neutral/ground bond at the source.

"A system bonding jumper must be installed between the neutral terminal of a separately derived system and the circuit equipment grounding conductor [Article 100 Bonding Jumper, System and 250.30(A)(1)]."
I don't have any issue when plugged into my generator. I made a cord specifically for plugging into a 30A receptacle and plugging into my 50A trailer. I also had to make a neutral/ground bonding plug for my EMS to allow power into the trailer. I also use the same cord to plug into a pedestal that only has 30A available. The reason I made a cord to do this is because with the generator on the back of my trailer the 50A cord is about 5 feet short and would require me to get my extension cord out. 30 feet of 30A cord is much easier to deal with than 45 feet of 50A cord.

 

[MnTom-FRF]

Is this one of those "less expensive" inverters that reference 60V to ground on both the hot and neutral? It is beginning to look like that........

 

[TitanMike]

Is this one of those "less expensive" inverters that reference 60V to ground on both the hot and neutral? It is beginning to look like that........

There's a big difference between "utility" supplied power systems and the typical RV generator or inverter supplied power.

Utility power has used an "earth return" from local transformers in many cases where inverters and generators use the neutral to complete the circuit from powered devices.

Different issues and since code is dealing with utility power and permanently installed non-portable generators it does get confusing. Just remember today's inverter type and conventional small portable generators sold in the US don't have bonded neutrals.

The only way one can come in contact with any voltage on a neutral is essentially "go looking for it" .

I think you are over-thinking this as as there numerous inverters of all types in use Whole House powering RV's without issues.

 

[MnTom-FRF]

Well, I have pretty much decided that I am not going to try to utilize this inverter for my trailer. I do not like the idea of having a potential of 60VAC neutral to ground and I would also need to bypass my surge protector. My surge protector was doing its job by not allowing the inverter to power the trailer due to the voltage on the neutral. I am going to look around for a better inverter.

 

[TitanMike]

Well, I have pretty much decided that I am not going to try to utilize this inverter for my trailer. I do not like the idea of having a potential of 60VAC neutral to ground and I would also need to bypass my surge protector. My surge protector was doing its job by not allowing the inverter to power the trailer due to the voltage on the neutral. I am going to look around for a better inverter.

Take a look at a Victron Multiplus-II which provides 2x120 for 50 amp systems and also charges batteries. Will also act as UPS should shire power fail. In the same price range as "good" Inverter chargers but can also integrate with other Victron components like the monitors-, etc.

 

[MnTom-FRF]

Take a look at a Victron Multiplus-II which provides 2x120 for 50 amp systems and also charges batteries. Will also act as UPS should shire power fail. In the same price range as "good" Inverter chargers but can also integrate with other Victron components like the monitors-, etc.

Thank you, Sir! I will look into that one!

 

[TitanMike]

I do believe NEC requires a neutral/ground bond at the source.

Very true but here's the rub.

NEC does not apply to RV's or Boats, just RV parks and Marina's.


RVIA has adopted NEC but there's no requirement that RV manufacturers follow it.

NEC is not "Law" until it's adopted by "local authority".

FWIW Victron states that only inverters of 16kva (12kva for their Compact) require a bonded neutral.

This hints that smaller inverters do not require bonded neutrals. Most references I've read state bonding at main panel (shore power) and at generator when using it instead of shore power. Only references I've read re: inverters has been for the larger ones used for non-mobile off grid solar installations where NEC is used.

 

[jimmoore13]

I think you have the answer you need.

I'm going to jump on some specs you provided.
400 AH (rated?) of FCLA battery power...which I read as 200 AH usable.
3500 watt inverter.

This calculator will help you. https://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.html
For boondocking with the battery as the main source of power, you must enter 12 into the voltage and watts go into the power box on the calculator.

A 3500 watt inverter will pull 292 AMPS from your battery bank at full power. Your battery would last about 40 minutes with that draw. And actually it would be substantially less, because at very high current draws, the battery rating no longer holds up. Typical lead acid batteries are rated at a 20 amp draw for an extended period...not nearly 300 amps.

Will you use all of that? I expect not. But, since you are installing the inverter, I don't know what your experience with inverters is. That handy calculator is your friend.

Got a 600 watt coffee maker that will run for 15 minutes through the inverter drawing from the battery? The coffee maker will draw 50 amps at 12 volts (because your battery bank is the ultimate source of the power) for 1/4 hour (15 minutes). Making coffee will cost you 12.5 AH of the available 200.

Because you chose such a large inverter, I will assume (yes, always dangerous ) that you may have plans to run quite a few 120 volt loads when boondocking. What I'm pointing out is that 200 USABLE Amp Hours are far less than you might think when it comes to having enough battery to run 120 volt loads through that huge inverter.

Know your loads. Know your current draw. Know that very high current for extended periods will exhaust your battery bank more quickly than the math suggests. Know that draining lead acid batteries below about 50% (about 12.2 volts) will damage them and shorten their lives. And know that, even if you have 400 USABLE amp hours of battery...one helluva lot of lead acid battery capacity...it really ain't that much with a 3500 watt inverter sucking on that battery bank.

I know you didn't ask, but something about your question suggested this info might be helpful. And BTW, I hope your inverter is connected to the battery bank with cables the size of your thumb, because 300 amps would make a #6 AWG glow like an incandescent light bulb.

If you knew all of this already, good. If not, I hope it helps. I'll shut up now.

 

[MnTom-FRF]

Jim, Thank you for the info. As I said, I acquired this inverter, so I am not out much for not using it (which I decided not to use it), but yes, I have 4 100AH FLA batteries (I know that only gives me 200AH), but I was trying to prove to myself that it would work before I invested in Li-on batteries and quite possibly solar. Yes, I know that even with 100% efficiency the batteries would not last long since if I pull 20A 120VAC it would take 200A 12VDC. In reality it would take 235+ amps 12VDC to give me 20A 120VAC. Like I said, this was more of an experiment for me than anything else. I do not like the idea of having 60+ VAC coming from the neutral like this cheap inverter has. Too much potential to have a serious issue in my mind..........
Oh, yes, I did use #2AWG 12" long to hook everything up...........

 

[Aussieguy]

the reason to go to a 3500w inverter is usually NOT so you can continuously draw that amount

you still have to power share..... use the 3500w to take care of the larger starting loads
example watching TV and using the microwave at same time you need the 3500 to get those micro-thingies excited ...so you would only on the large loads for a very short period of time and even then the remaining microwave load is on for maybe 10 minutes or so.


Then go back to a base load of TV+ Fridge etc ....sitting happily waiting for the next BIGGGIEEEE load


I would hope no one expects a 12v Inverter to putting out 3500w full time
wiring and connections for 12v is gonna be big but for real power hungry users they should seriously be looking to system around $10-15,000 .... which will be mostly for battery capacity...
why go big inverter which is a relatively small $$ component and NOT be able to use it cause the battery will drain in a hour?



battery and solar will the the expensive part of the equation
probably should go to a 48v system where loads and wires is only a 1/4 the size ... if you want to use closer to 3500w a lot...

 

[MnTom-FRF]

I do have a residential fridge, so that is one reason for trying what I am, but there is a 1000w inverter factory installed just for the fridge. I am not sure about how much boondocking I am going to be doing. It depends on what my girlfriend wants to do too. I only have a 54 gallon fresh tank and 30 gallon black....... I could get a bladder and pump for the fresh and macerator for the black I guess........