What switch accepts inputs from 2 different DC sources and has a single DC output

Thread Starter

jwbutler123

Joined Jul 24, 2017
5
I'm remodeling an RV and want to power the DC components by battery or by AC2DC converter. When shore power is available the DC load panel will receive power from the converter and when no shore power is available the power will come from the batteries. What switch would be best used for this situation?
 

ericgibbs

Joined Jan 29, 2010
9,533
hi 123,
You could consider a relay, the coil for the SPCO relay is powered from the shore DC source and will auto select if shore power is available.
Relays with suitably rated contacts are quite robust.
E
 

mcgyvr

Joined Oct 15, 2009
5,394
Typically this is done via "diode or'ing"

But there are also jacks that have internal switching (shunt) too so that all of this is automatic
 

MaxHeadRoom

Joined Jul 18, 2013
19,983
Plus two on the steering diodes, which should automatically take care of it.
But preferably the shore power should be slightly higher potential than the battery supply.
Max.
 

crutschow

Joined Mar 14, 2008
24,318
The TS mentioned an AC2DC converter so I would assume shore power is AC.
I vote for an AC SPDT relay energized by the shore power for best efficiency.
 

Thread Starter

jwbutler123

Joined Jul 24, 2017
5
All,
Thanks for your time and for the great information. I did the research on spdt relays, very cool stuff. I think this is the direction I'm going to go. Again thanks to all...
 

AnalogKid

Joined Aug 1, 2013
8,302
Shore power is AC, so there would be no extra conductors. +1 for Wally.

TS: What is the max power being controlled, either at the AC or DC level?

ak
 

Thread Starter

jwbutler123

Joined Jul 24, 2017
5
Shore power is AC, so there would be no extra conductors. +1 for Wally.

TS: What is the max power being controlled, either at the AC or DC level?

ak
The AC2DC converter will output 12v, 25amps, 300watts. The DC load panel controls loads to the following
o water pump
o lights
o usb charging ports
o 12v aux ports
o audio system
o communications gear
 
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