Maker Pro
Maker Pro

Mixed voltages at negative common connection?

carilchasens

Jun 7, 2016
3
Joined
Jun 7, 2016
Messages
3
60V DC and 12V DC, both with the negative on a common ungrounded connection... what would you call a setup like that? What would be the effect? The thing I have in mind is an ungrounded photovoltaic system, with the 12V battery negative and the 60V PV negative on a common connection together at the charge controller.
 

hevans1944

Hop - AC8NS
Jun 21, 2012
4,880
Joined
Jun 21, 2012
Messages
4,880
I see nothing wrong with that. What is the battery used for? Are you going to charge it from the PV panel with a buck converter between the PV panel and the battery? That will work.
 

Harald Kapp

Moderator
Moderator
Nov 17, 2011
13,719
Joined
Nov 17, 2011
Messages
13,719
Welcome to EP.

what would you call a setup like that?
As far as I know there is no dedicated name for it. Maybe 'common ground' is the nearest expression, even if there is no connection to earth (what you refer to as ungrounded. 'Ground' is commonly used to denote the common potential in a circuit (also quite regularly called 0V).

What would be the effect?
Effect of what? Of being common or of being ungrounded?
Having a common potential (ground, 0V whatever you like to call it) is essential for two electrical circuits to work together. Energy (power, signals...) that goes from one circuit into the other needs a path to return to the source where it came from. Any electrical circuit neds to be able to form a closed circuit for current to flow. No closed circuit -> no current -> no power or information.

The thing I have in mind is an ungrounded photovoltaic system, with the 12V battery negative and the 60V PV negative on a common connection together at the charge controller
This is a regular setup. It wouldn't work without the common connection unless the charge controller is completely isolated (using e.g. an internal transformer for potential separation), which is quite uncommon.
 

carilchasens

Jun 7, 2016
3
Joined
Jun 7, 2016
Messages
3
I see nothing wrong with that. What is the battery used for? Are you going to charge it from the PV panel with a buck converter between the PV panel and the battery? That will work.
The 12 Volt battery bank is for 12V lights, radio. inverter. The common connection would be on a MPPT controller. (We are upgrading a system we acquired in a previous century) Thank you for mentioning the buck converter.. I googled it and am a lot less confused about how the setup could work..
 

carilchasens

Jun 7, 2016
3
Joined
Jun 7, 2016
Messages
3
Welcome to EP.


As far as I know there is no dedicated name for it. Maybe 'common ground' is the nearest expression, even if there is no connection to earth (what you refer to as ungrounded. 'Ground' is commonly used to denote the common potential in a circuit (also quite regularly called 0V).


This is a regular setup. It wouldn't work without the common connection unless the charge controller is completely isolated (using e.g. an internal transformer for potential separation), which is quite uncommon.

Harald, thanks..
 
Top