Do I need a inverter with a terminal block (hardwire)

[jdfrye]

Looking at a 2000w inverter and the two I'm looking at are the

GIANDEL 2200W Pure Sine Wave​

and the

WZRELB Reliable 2000W Pure Sine​

one has a terminal block for high power appliances plus two standard US plug in's
The other has only two standard US plugs

Question:
Using a heavy extension cord, could I just use one of the plug outlets in the end of the inverter and use the other end to then splice into the power panel to power the RV?
Or should I get the inverter that I can tie into the terminal block and run that into the RV power panel

 

[jdfrye]

Amazon.com

Actually I guess I'll pull the trigger on the link above tomorrow unless someone says I can use the outlet on the back of the plugin type inverter to power my panel.
I'll be using a transfer switch also. the TS-30

 

[Bud Martin]

You should find out if the Neutral can be bonded to AC Safety Ground or not, look at the user manual to see what it says about it.

 

[jdfrye]

to answer my own question I went with the Giandel with the terminal block (& 3 yr warranty). Looks like I can draw more watts out of the block then just out of the single socket.

 

[Bud Martin]

You should also use the Ohm meter to verify that the Hot, Neutral, and Ground of the AC outlet sockets matched the Hot, Neutral, and Ground of the terminal block, my Reliable has the Hot and Neutral reversed on the AC socket compared to the terminal block.

 

[jdfrye]

You should also use the Ohm meter to verify that the Hot, Neutral, and Ground of the AC outlet sockets matched the Hot, Neutral, and Ground of the terminal block

They match..but here's my head scratcher
When I test the line and neutral together I get 120v. When I test the line and ground I get 66v
I test the neutral and the ground I get 54v
Why is that? These measurements are at the inverter terminal block.
Shouldn't I get 120v from the line to the ground and almost 0v from the neutral to the ground like I do in my house or when the RV generator is running?
The inverter seems to be running everything fine.

 

[Bud Martin]

Most of these inverter has floating output (Neutral is not bonded to Safety Ground, you can easily find out using Ohm meter between N and Gnd, it should show <1 Ohm (meter probe wires resistance)), the Voltage you are seeing is due to the safety Y capacitor between L and Gnd, N and Gnd .
That is why I suggest you to find out if the Neutral can be safely bonded to the Safety Ground or not without damaging the inverter AC output circuit.

 

[Hedges]

Put an incandescent lam between line and neutral, then test voltage.
Put an incandescent lam between line and ground, then test voltage.

If floating, the resistance will pull it each way. Then grounding neutral is known to be OK.

 

[jdfrye]

Okay. I will find out but I'm dumb and don't understand this
" Can be bonded to the safety ground or not"
Is this something I can do with a meter? Sorry I'm a idiot when it comes to this. If you say connect this to this I can do that. Lol.

 

[jdfrye]

Put an incandescent lam

Yikes! I'm in way over my head. What is a "incandeacent Iam?

 

[Bud Martin]

Also do the test between Neutral and Ground using the same incandescent lamp, if the lamp light up then you cannot ground the Neutral since the output may be full bridge output topology, I use 120V 7W incandescent night light for testing.

 

[jdfrye]

Also do the test between Neutral and Ground using the same incandescent lamp.

Okay " lamp" this slang is going to kill me. Haha
I will find something to rig up to make this simple test lamp.
Thanks guys for the concern and help

 

[Hedges]

Yikes! I'm in way over my head. What is a "incandeacent Iam?

A key that wasn't pressed all the way.
And I didn't proof-read my own typing.

"lamp". A light bulb. It serves as a safe load to gently short an electrical terminal, see if it can be biased to a different voltage.

But put in the neutral-ground test I neglected to list.

(Looks like you made a typo too, transcribing my words. I probably wouldn't have made that error - I cut and paste when I can.)

 

[Hedges]

I will find something to rig up to make this simple test lamp.
Thanks guys for the concern and help

Could be a couple alligator clips to the pins of a floor lamp. Or wires to a spare electrical outlet you can plug the lamp into.

I finally made myself a cheater cord with safety shrouded banana plugs, makes it convenient to test electrical outlets with DMM and other work. Stackable banana plugs, which means I have to restrain my self from doing anything stupid like plugging them into each other.

 

[jdfrye]

I've been thinking and thinking ?
Does this really apply to me since I never explained my situation.
I have a RV which will always be off grid unless I start the generator or plug in shore pwr in which that case I have a transfer switch that never lets the inverter touch the outside grid.
If it does apply to me then I will get that light to do the test. If I never do the test and leave as is what worst case sinario?
Again I appreciate your replies

 

[Hedges]

We don't like "Neutral" to be electrified and carry voltage above ground.
If you had some two prong devices in your RV like a large, old, television set the chassis could be hot. Lamp sockets could have the nearly exposed outer threaded contact hot. Switches would turn off only the "Line", leaving "Neutral" unswitched, which could be hot.
GFCI outlets (built-in ones) only open Line, rely on Neutral being grounded. A hazard outdoors, also in kitchen/bath.

"Grounded" in an RV is a funny concept.
If plugged into shore power, that should provide bonding of neutral to ground. Apparently, sometimes have Line and Neutral reversed. Caveat Camper.
If not plugged into shore power, you're supposed to dynamically bond ground to neutral. But unfortunately nothing is actually wired to an earth ground rod. One guy noticed his dog didn't like climbing the step of his RV (when wired to remote PV array.)
With generator, good chance it has floating neutral, not grounded. But your inverter (if auto switching) would think generator was shore power providing ground. So you have to make it work.

But in your case, transfer switch. Does that isolate neutral (not just line)? You wouldn't want a neutral/ground bond at the inverter with neutral connected to shore power which also grounds neutral.

 

[jdfrye]

Yes, my transfer switch isolates the inverter line and neutral. When on gen/shore power it connects to the AC panel. When not detecting shore/generator power then it switches to inverter power.
Sounds like I still should see if my neutral is bonded or not. Am I saying that right?

 

[Hedges]

Yes, and we think your neutral is not bonded.
The light bulb test can be used to see if your inverter will tolerate bondage (some drive symmetric +/-60V and can't be bonded.)
What you want is to use shore power bond, provide bond when disconnected. Some inverters do that automatically (some UL standard for mobile applications). You also need to find a way to bond when fed from generator.

Idea:
Shore power cord inherits N-G bond from shore power pedestal.
When not on shore power, plug that cord into a socket that just has N-G wired together. And, has L/N/G going to another plug, for the generator.
Instead of automatic bonding, you get bonding by plugging into sockets.

Make sure both generator and inverter tolerate N-G bond.

Ahh, but one problem with my idea is that transfer switch would isolate neutral coming from cord and N-G socket. You could do it with separate cord in breaker panel, but then you can make the mistake of keeping that bonded even when on shore power, because it is two different plugs. My idea would have been OK if shore power cord went to inverter AC input. Yours appears to be inverter only, not inverter/charger.

OK, bond neutral to ground at inverter output. Plug transfer switch AC input cord directly into shore power pedestal. Or, into a socket with N-G bond which has a cord to generator.

 

[jdfrye]

Heading to work... When I get home I will read this 30 times to wrap my head around it and get back to you.
How much do I owe you?

 

[Hedges]

A virtual glass of scotch would be fine.

The goal is just to always have Neutral at earth (or chassis) potential.
Some how, we also want chassis at earth potential. I'm not quite sure how to guarantee that, for mobile application without grounding rod.
One can buy portable GFCI, but those interrupt line and neutral. If ground pin were electrified, doesn't protect against that.