got a tingle off the inverter chassis

[John Frum]

Was putting in my new Victron Smart Battery Protect just a minute ago.
Its hot and I was a bit sweaty and I was leaning across the inverter.
I got a tingle on my forearm.
I didn't think 26 volts could be felt.
I wonder if I was flirting with a Darwin award.

 

[Picasso]

Dont think I've ever felt 24volts, 48+ yes many times cant recall being zapped yet playing with 24.

Is your neutral floating? Tired to ground with a real ground rod?

 

[Bud Martin]

Was putting in my new Victron Smart Battery Protect just a minute ago.
Its hot and I was a bit sweaty and I was leaning across the inverter.
I got a tingle on my forearm.
I didn't think 26 volts could be felt.
I wonder if I was flirting with a Darwin award.

Is the unit also connected to utility?

 

[John Frum]

Is the unit also connected to utility?

Nope not connected to utility.
I checked and there is 26.22 volts dc between inverter case and the positive busbar.
My meter doesn't show any ac voltage between the 2 points.
I guess I can feel ~26VDC on the inside of my forearm where all the veins are close to the surface.

 

[Frick]

Human conductivity varies significantly As does nerve sensitivity. Old army friends use to talk about how some guys just grabbed live wires with ease, noting mild shocks. Others felt very electrocuted and stopped doing that, and they said that led to some dropping out of that line of work While others went on to become electricians as it didn’t bother them.

sweat which is salt water is conducting rather well, dry skin not so much. I have noticed I could feel 12v while bent awkwardly around a hot compartment over components like filling lead acid batteries and touching a terminal with an uninsulated wrench and body parts touchI got metal chassis parts, I may also be more sensitive...

I dont think it can be fatal or risky though beyond dropping Metal across live Components and causing a short/fire.

 

[Lt.Dan]

I remember Will talking about it briefly in one of his videos, I think in the solar shed. He was sweaty and reaching across a 24v battery and he got a little tingle.

I do believe everyone is different as well, some higher than others. I have an electrician friend that ive known since elementary school, and he can grab live 120v and it doesnt seem to affect him at all, but I'll scream like a little girl!

 

[Steve_S]

LOL, I've been Zapped by my 24V system, more than once... sweaty (salty) body can get ya nice jolt to snap you back to reality. IMO, a good Coffee is prefferable.

 

[chrisski]

Do all your components that have a chassis ground connected to chassis ground? My inverter and three charge controllers are all connected to chassis ground by multistrand copper 8 AWG wire. I’d be surprised if the battery protection does not.

In the past I’ve felt a shock from components metal casing. I tried to put a multimeter between myself and the case to measure voltage, but this did not work. I’ve also looked at some people who feel a shock getting into their RV like you’re explaining, but never see a resolution to that. RV chassis ground does not necessarily mean earth ground especially if it sits on top of rubber tires and plastic leveling squares.

 

[HRTKD]

The shock when touching the RV door frame is an issue with shore power grounding I believe. It can be a problem either in the RV or within the pedestal. I've read posts on other forums about it and I was concerned enough that I tested it out on my RV and didn't have any issues.

The tingle from the inverter could be a bad ground on the inverter. I can touch my 1000 watt 12v inverter all day long without any effect. I routinely place tools and fasteners on the top of the inverter, simply because it's a convenient flat spot in the compartment. My inverter is grounded on the 12v side to the chassis.

 

[wholybee]

Nope not connected to utility.
I checked and there is 26.22 volts dc between inverter case and the positive busbar.
My meter doesn't show any ac voltage between the 2 points.
I guess I can feel ~26VDC on the inside of my forearm where all the veins are close to the surface.

This leads me to believe that the chassis is (probably) grounded properly. Is there any voltage between the chassis and the Negative busbar? There should not be.
Remember, to get a shock you need to make contact at 2 places. Is it possible that you were touching something else that was energized when you felt the shock on the inverter case?
You stated that the unit is not connected to utility. Is anything else in the vehicle connected to AC power?

 

[John Frum]

This leads me to believe that the chassis is (probably) grounded properly. Is there any voltage between the chassis and the Negative busbar? There should not be.
Remember, to get a shock you need to make contact at 2 places. Is it possible that you were touching something else that was energized when you felt the shock on the inverter case?
You stated that the unit is not connected to utility. Is anything else in the vehicle connected to AC power?

Its not a vehicle its a stationary system.
I was touching the load side lug for the dc fuse block with my sweaty forearm resting across the inverter chassis.
I will check to see if there is any potential difference between the chassis and the negative busbar but I don't expect any as the inverter negative terminal and equipment ground are connected to it.

 

[John Frum]

If it were a 48 volt system and I was using both hands it might have ended badly.
This was a good lesson to me.
Hope those of you with 48 volt rigs also take note.

 

[wholybee]

Its not a vehicle its a stationary system.
I was touching the load side lug for the dc fuse block with my sweaty forearm resting across the inverter chassis.
I will check to see if there is any potential difference between the chassis and the negative busbar but I don't expect any as the inverter negative terminal and equipment ground are connected to it.

Ahh. "I was touching the load side lug for the dc fuse block with my sweaty forearm resting across the inverter chassis."
Best practice is to have plastic covers over positive connections, and remove power before removing the covers. Even 12V can be dangerous. I have felt a tingle from a 9 volt battery on wet/sweaty skin.