Giandel NO Ground-Neutral Bonding

[MrPhoton]

RE: Giandel advised - Ground/Neutral Bonding not supported - floating only - 24V / 3000W PSU

Hi All,
Giandel recently advised me they do NOT support bonding of Ground to Neutral with their 24V/3000W/PSU inverter.

The Tesla charger wouldn't function along with other devices that did soft 5mA pulse to search for neutral/ground connection.

Giandel's advice was to drop a GFCI (essentially becomes ungrounded GFCI like in old houses) - and then the device thereafter. It did trick some of the devices.

That said - I'm likely to abandon and purchase a 48V UL-rated Inverter/MPPT combo that can handle a Neutral/Ground bond near inverter or at whatever panel is used.

Would someone be able to help clarify if the Neutral/Bond limitation is related to High-Frequency vs. Low-Frequency Inverter architecture? Is the LF required? I've seen references to some HF units that can hand neutral bond as well, so I'm trying to understand what Architecture/Specification of the inverter conveys that it can handle neutral/ground bonding.

Appreciate the group's knowledge in this regard.

 

[FilterGuy]

RE: Giandel advised - Ground/Neutral Bonding not supported - floating only - 24V / 3000W PSU

Interesting, without a N-G bond the ground wire in your AC wiring is of limited value. A short to the ground wire will not clear the fault.

Would someone be able to help clarify if the Neutral/Bond limitation is related to High-Frequency vs. Low-Frequency Inverter architecture?

I see no reason why it would be a HF/LF thing. I think it is more of a good/bad design thing. However, the low frequency inverters tend to be higher quality, more expensive and better made so I can believe that they would more likely to have better designs.

so I'm trying to understand what Architecture/Specification of the inverter conveys that it can handle neutral/ground bonding.

My experience is that a lot of the low cost inverter makers are almost criminally negligent in explaining how they deal with N-G bonding.

 

[John Frum]

This picture shows an equipment grounding lug.

Amazon.ca

Test the inverter to see if there is continuity between the ac ground terminal and the equipment grounding lug.
Then check for continuity between the ac ground terminal and the ac neutral terminal.
Then report back.
Please and thanks.

 

[MrPhoton]

Interesting, without a N-G bond the ground wire in your AC wiring is of limited value. A short to the ground wire will not clear the fault.


I see no reason why it would be a HF/LF thing. I think it is more of a good/bad design thing. However, the low frequency inverters tend to be higher quality, more expensive and better made so I can believe that they would more likely to have better designs.


My experience is that a lot of the low cost inverter makers are almost criminally negligent in explaining how they deal with N-G bonding.

Love that last line. They'd suggested that if I bond Neutral and Ground at inverter - that it would risk shock on the chassis. In light of this - interesting that the manual would include reference to support fixed sites in addition to vehicle/maritime. Presuming they didn't want to risk losing that market.

I'll chalk this up to - should have seen this coming. Hunting for the right UL-rated All-in-One instead. Wondering if MPPsolar and Growprep are a different grade - or just time go Victron.

 

[FilterGuy]

Grounding details for specific make/model of inverters

To get to the paper, click on the orange button at the top of the screen. It is important to understand how an inverter handles grounding in order to set it up correctly. Unfortunately, many inverters do not provide adequate documentation on...

diysolarforum.com

 

[roadrunner]

Looking at amazon, are their any off grid inverters in the 2000 watt to 3000 watt range that have a neutral/ground bond and are their any that the low voltage disconnect can be adjusted, that members here have bought, 24 volt would be best, my trailer does have a separate ground and neutral lug, built in 1980, its a mobile home. if im going to invest in something might as well get one that is good for all if its possible. cant find one yet

 

[John Frum]

Looking at amazon, are their any off grid inverters in the 2000 watt to 3000 watt range that have a neutral/ground bond and are their any that the low voltage disconnect can be adjusted, that members here have bought, 24 volt would be best, my trailer does have a separate ground and neutral lug, built in 1980, its a mobile home. if im going to invest in something might as well get one that is good for all if its possible. cant find one yet

Configurable low voltage disconnect is not usually a feature of discrete inverters.
To get decent configurability usually means a micro-processor and the micro-processor comes with the economy of scale provided by an inverter/charger.

 

[roadrunner]

so would have to buy an inverter/charger combo then

 

[John Frum]

so would have to buy an inverter/charger combo then

Yes.
You get these benefits

1. inverter
2. ac charger
3. automatic transfer switch
4. often times a microprocessor

The microprocessor allows granular configuration of

1. low voltage cutoff
2. charge voltage
3. charge current
4. charge termination
5. charge initiation
6. possibly much more?

Plus its just about impossible to get a discrete low frequency inverter anymore.

 

[roadrunner]

thanks, ill go check amazon

 

[FilterGuy]

Looking at amazon, are their any off grid inverters in the 2000 watt to 3000 watt range that have a neutral/ground bond and are their any that the low voltage disconnect can be adjusted, that members here have bought, 24 volt would be best, my trailer does have a separate ground and neutral lug, built in 1980, its a mobile home. if im going to invest in something might as well get one that is good for all if its possible. cant find one yet

The important thing is to know if it has an N-G bond or not. If you know what the inverter has, you can build a proper system.
The key is that there should only be one N-G bond in the system. If the inverter has one, the rest of the system should not. If the inverter does not have an N-G bond, you should put one in your breaker box.

The reason to have a N-G bond is to ensure that if there is a short to the ground wire, the breaker will immediately pop. (This is called clearing the fault).
The reason there should only be one N-G bond is that if there is more than one, current will flow on the ground safety wire.

Note: The above comments are for US, CANADA, & Mexico. Other parts of the world deal with this differently.

 

[roadrunner]

my mobile home was built in 1980, no N-G bond, i have a seperate neutral lug and a seperate ground lug at main panel, inside trailer on wall in master bedroom

 

[John Frum]

my mobile home was built in 1980, no N-G bond, i have a seperate neutral lug and a seperate ground lug at main panel, inside trailer on wall in master bedroom

It does have a neutral ground bond when connected to shore power and it can potentially have a neutral ground bond when powered by a generator or inverter.

 

[roadrunner]

never will be powered by shore or buy a gen set

 

[solar8484]

They'd suggested that if I bond Neutral and Ground at inverter - that it would risk shock on the chassis.

This risk is probably true for all floating neutral inverters if the inverter ground is not also connected to real earth ground (e.g. a ground rod).

 

[John Frum]

never will be powered by shore or buy a gen set

If you really mean never then you may not want an inverter/charger.
There is a way to add configurable low voltage disconnect to a discreet inverter.
The inverter needs to support remote control.
You "remote control" it using a victron smart battery protect.

 

[roadrunner]

so the battery protect would go between battery and inverter then

 

[John Frum]

so the battery protect would go between battery and inverter then

Nope, can't do that.
The battery protect can't handle the inrush current to prime the inverters capacitors.
The inverter remote control is "switched" by the battery protect.
That is why I mentioned the inverter needs to support remote control.

 

[John Frum]

@roadrunner an rv that never connects to shore power or a generator is a pretty unusual usage model.
Just saying.

 

[roadrunner]

i dont have an rv, i have a mobile home, trailer, so i need an off grid with a remote control, i wanted a 24 volt model but maybe i can use a 12 volt but i plan on using 250watt panels at 40 vmp or open circuit voltage, can i use 40 volt panels on a 12 volt battery bank and just use large cables to save on losses