Missing ground on forward cabin 12 volt outlet.

[LADYBUG TOO]

The ground on the forward cabin, port side 12 volt outlet is missing. I plugged in my CPAP only to find no power. Upon removing the outlet I found that the ground wire was never installed. Can I tie into the 120 volt ground? Or, do I need to run a ground somewhere else. The 120 Volt outlet is directly below the 12 volt so I could fish a ground to it. I am assuming that the ground is common to both systems. I am not sure what Ranger does with the neutral.

Pat, Ladybug Too

 

[RProffer]

12v and 120v ground systems should be kept separate. You could have problems if you tie the two together. I am sorry I cannot give a suggestion on where to connect it as I have a R21EC.

 

[Andrew Custis]

You can use the 120 ground as a 12 volt ground. We tie the 12 volt and 120volt grounding system together on all boats.

 

[RProffer]

That is interesting Andrew. I looked it up in a marine electrical book and that is the way it should be. The grounds for the DC and AC circuits should be connected together.

You could have some problems though with some sensitive electronics. I have seen many times where two electronic devices with different potentials/voltages would have problems when their grounds were connected either accidentally or on purpose. Usually, the lower voltage device would stop working or behave erratically. I am not an electrical engineer and do not understand the theory behind it, but the electrical engineers I have talked to say it is because the devices have different potentials (voltages).

 

[walldog]

That is interesting Andrew. I looked it up in a marine electrical book and that is the way it should be. The grounds for the DC and AC circuits should be connected together.

You could have some problems though with some sensitive electronics. I have seen many times where two electronic devices with different potentials/voltages would have problems when their grounds were connected either accidentally or on purpose. Usually, the lower voltage device would stop working or behave erratically. I am not an electrical engineer and do not understand the theory behind it, but the electrical engineers I have talked to say it is because the devices have different potentials (voltages).

Being as the grounds are bonded together, you should have no trouble with electronics, sensitive or otherwise. The problems you could have is when you have two separate ground systems and there exists a small difference in potential (voltage) between the two grounds.