Stop Dc back feeding into Ac supply

[Electegrity84]

How can I and where should I install in circuit a diode? Diodes? Or any other device that could stop DC short to chassis on my RV from back feeding when i plug my 120 volt 20 amp system into RV which is causing havoc in damage to the A/C gfci breakers frying them constantly ? Also this will effect the AC sin was?

 

[Aaron b]

I have no idea about your application but a capacitor is used to block DC whilst allowing AC to pass in some applications.

 

[Electegrity84]

I have no idea about your application but a capacitor is used to block DC whilst allowing AC to pass in some applications.

I’m getting a DC back feed sometimes on an RV unit from a short somewhere that is intermittent so I can’t find it but definitely the RV has a potential difference than I do so that’s why I’m getting zapped a bit and If I plug it in at home to 120 volt 30amp twist lock I use when company comes over and stays in air conditioning RV when other rooms are full. I also then I get a small shock from the touching the RV units metallic cover when I’m opening the cover to plug it in for my guests and that short is frying my gfci breaker in my house panel and a few conservation parks also so I thought maybe I can fix this with like you say a capacitor? Not a diode? Any other devices out there ?

 

[mainline]

I’m getting a DC back feed sometimes on an RV unit from a short somewhere that is intermittent so I can’t find it but definitely the RV has a potential difference than I do so that’s why I’m getting zapped a bit and If I plug it in at home to 120 volt 30amp twist lock I use when company comes over and stays in air conditioning RV when other rooms are full. I also then I get a small shock from the touching the RV units metallic cover when I’m opening the cover to plug it in for my guests and that short is frying my gfci breaker in my house panel and a few conservation parks also so I thought maybe I can fix this with like you say a capacitor? Not a diode? Any other devices out there ?

My advice is to get an electrician to have a look at it.

 

[davesparks]

I’m getting a DC back feed sometimes on an RV unit from a short somewhere that is intermittent so I can’t find it but definitely the RV has a potential difference than I do so that’s why I’m getting zapped a bit and If I plug it in at home to 120 volt 30amp twist lock I use when company comes over and stays in air conditioning RV when other rooms are full. I also then I get a small shock from the touching the RV units metallic cover when I’m opening the cover to plug it in for my guests and that short is frying my gfci breaker in my house panel and a few conservation parks also so I thought maybe I can fix this with like you say a capacitor? Not a diode? Any other devices out there ?

You need to find, and fix, the fault. There is no component you can install to magically make a fault disappear.

If the fault is bad enough to actually damage a protective device (the gfci in this case) and is giving you electruc shocks then it is potentially very bad, not to mention dangerous.

Where is the DC coming from and what voltage is it at?

 

[Lucien Nunes]

If DC from the vehicle electrics is getting into the 120V system then 120V AC could get into the 12V system, resulting in a serious shock hazard. You must fix the cause of this problem, not mask the symptom in any way. If it is code compliant then a fault between the two systems is extremely unlikely, so there might be some significant damage or incorrect wiring.

As above an electrician, preferably armed with an insulation tester, would be the first choice for a solution.