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Changeover Switch

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BillN

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Looking for a manual Changeover switch to divert 400W of solar panels output to two places?
1. charge controller to battery
2. output to my Ecoflow power generator
3. off

Thanks
 
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I find that two DC breakers are the easiest to implement solution.
Turn one Off and than the other On. In image below I had disconnected the leads going to a alternative SCC but it should give you the concept.
 

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Mattb4 said:
I find that two DC breakers are the easiest to implement solution.
Turn one Off and than the other On. In image below I had disconnected the leads going to a alternative SCC but it should give you the concept.
Click to expand...
Is this really the answer? I have the exact same request as the OP. I am 'shocked' that there is not an industry solution for a manual change over switch to divert incoming solar power between two places (and potentially the third being off).
 
I am going to use Solar Disconnect Switch. I think it is cheaper than a box for breakers plus the breakers.
www.currentconnected.com

Solar PV DC Quick Disconnect Switch | Current Connected

Discover our Solar PV Quick Disconnect Switch with user-independent switching action, ensuring a lightning-fast break/make action in just 3ms!
www.currentconnected.com www.currentconnected.com
richsolar.com

Solar PV DC Quick Disconnect Switch RS-i4, 1500Volt 32AMP, 4 Poles 2 S

FEATURES Quickly disconnect DC power from your solar array to the charge controller, batteries and/or inverters. Outdoor rated Off and on grid applications. Isolated SAFE-LOCK with three rotational positions, reducing the risk of tampering. Single pull double throw 2 IO. Ensures the...
richsolar.com richsolar.com
 
DIYrich said:
I am going to use Solar Disconnect Switch. I think it is cheaper than a box for breakers plus the breakers.
www.currentconnected.com

Solar PV DC Quick Disconnect Switch | Current Connected

Discover our Solar PV Quick Disconnect Switch with user-independent switching action, ensuring a lightning-fast break/make action in just 3ms!
www.currentconnected.com www.currentconnected.com
richsolar.com

Solar PV DC Quick Disconnect Switch RS-i4, 1500Volt 32AMP, 4 Poles 2 S

FEATURES Quickly disconnect DC power from your solar array to the charge controller, batteries and/or inverters. Outdoor rated Off and on grid applications. Isolated SAFE-LOCK with three rotational positions, reducing the risk of tampering. Single pull double throw 2 IO. Ensures the...
richsolar.com richsolar.com
Click to expand...
This does not seem to address the request of the OP and myself. I already have a dual pole disconnecxt. I am looking for a manual transfer switch instead, which would divert power between the SCC/battery, a Power Station with integrated SCC, or off.

I am amazed there seems to be one singular chinese made option for this.
 
Dustin Henderson said:
This does not seem to address the request of the OP and myself. I already have a dual pole disconnecxt. I am looking for a manual transfer switch instead, which would divert power between the SCC/battery, a Power Station with integrated SCC, or off.

I am amazed there seems to be one singular chinese made option for this.
Click to expand...
The problem is the high DC voltage and amps for the "changeover" or "transfer" switch. Hundreds of dollars for it.

The cheapest option I found is to split the PV and feed it into separate disconnect switches for each device. Turn the switch on for whichever device you want to receive the power. Instead of One 3-position switch (A, Off, B), you have two 2-position switches (on/off).

Another option is to use an AC rated changeover switch, and be careful never to switch under load. They are not rated to break 400v DC.
 
DIYrich said:
The problem is the high DC voltage and amps for the "changeover" or "transfer" switch. Hundreds of dollars for it.

The cheapest option I found is to split the PV and feed it into separate disconnect switches for each device. Turn the switch on for whichever device you want to receive the power. Instead of One 3-position switch (A, Off, B), you have two 2-position switches (on/off).

Another option is to use an AC rated changeover switch, and be careful never to switch under load. They are not rated to break 400v DC.
Click to expand...
Hmm. Comments:

1) Is DC 40 volts (maybe 60 with a panel addition) and 10 Amps "high"? These are the limits of my scenario, I would think a DC switch exists to accommodate. I don't consider this high.

2) I thought about splitting the incoming before two switches. Seems hacky, but I am ignorant. What happens when both switches are on?

3) As in item 1, my Voltage here is 40, 10 Amps. 400Watts total panel that have maxed out in the last 300 days at 305 watts. I presume the AC rated devices should be available to easily accommodate? In my scenario, this would come after the current breaker switch, so could always be turned off fiorst, though not "enforced" mechanically...

Appreciate the discussion.
 
Unless I am missing something why do you need to switch under load? The din rail DC breakers ( BTW I find the Westinghouse version a better quality) should handle switching under load but it is best avoided as it wears out contacts.

ETA: Incidentally if you are powering different SCC's, and one has reached full charge and cut off PV production, there is little to no load to switch and the next SCC, even with a dead battery, takes a few seconds to recognize PV and set charging amps.
 
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So, for switching you could use an stanard Dual Pole Dual Throw (DPDT) DC switch- or a battery disconnect rated at 60vdc with a switching pattern... OR a DC contactor that does DPDT - Albright makes a bunch of these... or look on amazon for 'motor reversing' switches like what is used on a forklift or trolly car.

ON-OFF-ON or A-OFF-B depending on the vendor - this leaves the negatives tied together which could cause issues....
 
Mattb4 said:
Unless I am missing something why do you need to switch under load? The din rail DC breakers ( BTW I find the Westinghouse version a better quality) should handle switching under load but it is best avoided as it wears out contacts.

ETA: Incidentally if you are powering different SCC's, and one has reached full charge and cut off PV production, there is little to no load to switch and the next SCC, even with a dead battery, takes a few seconds to recognize PV and set charging amps.
Click to expand...
Doesn't HAVE to be under load. There is an existing breaker that can be used to remove load. It's an extra step, and an extra device.
 
robbob2112 said:
So, for switching you could use an stanard Dual Pole Dual Throw (DPDT) DC switch- or a battery disconnect rated at 60vdc with a switching pattern... OR a DC contactor that does DPDT - Albright makes a bunch of these... or look on amazon for 'motor reversing' switches like what is used on a forklift or trolly car.

ON-OFF-ON or A-OFF-B depending on the vendor - this leaves the negatives tied together which could cause issues....
Click to expand...
I will take a look. I suspect these require adding blade connections or something, rather than utilizing screw terminals like the rest of the devices in the system.
 
Well if money is no object midnite solars high end breakers are the ultimate choice. Will stop arcs dead in their tracks and handles 100's of amps depend on the breaker you pick.

Also it use lugs just like your batteries. No stupid screws to fight with.

Not cheap though and are HUGE in size so mini din rail boxes are not going to work.250amp breaker.jpg

Small breaker on the left is a full size house breaker aka whats in your mains breaker box. The middle monster is a midnite solar 250amp dc breaker.
 
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Dustin Henderson said:
Hmm. Comments:

1) Is DC 40 volts (maybe 60 with a panel addition) and 10 Amps "high"? These are the limits of my scenario, I would think a DC switch exists to accommodate. I don't consider this high.
Click to expand...
Sorry, I was thinking switching PV. If you are switching batteries, then 60v DC changeover switch would work.

Dustin Henderson said:
2) I thought about splitting the incoming before two switches. Seems hacky, but I am ignorant. What happens when both switches are on?
Click to expand...

It is a tradeoff between User Error and Cost. Isolation switches exist to eliminate user error, but they cost a lot more than two singe switches.

Dustin Henderson said:
3) As in item 1, my Voltage here is 40, 10 Amps. 400Watts total panel that have maxed out in the last 300 days at 305 watts. I presume the AC rated devices should be available to easily accommodate? In my scenario, this would come after the current breaker switch, so could always be turned off fiorst, though not "enforced" mechanically...
Click to expand...

Switching AC is easier because 120 times a second, the voltage is 0, and the device can create enough separation in that time to break the circuit. With DC voltage, you don't have that luxury, and the force of the voltage keeping the circuit closed has to be overcome.

Again, it is a matter of cost vs user error. If you will ONLY switch when voltage is 0, then a 120v AC 3-way switch will work (69 cents at Lowes). If you need a changover switch that works in any circumstance, then you have to payup.
 
sunshine_eggo said:
That's a 3 phase AC switch. What's its DC rating?
Click to expand...

He stated it was with zero volts/current - i.e. after the breaker was turned off - so no breaking of DC arc required - and pretty much any switch will do after that, particularly one with copper parts, silver contacts and 63a ac rated ... Were he switching higher than the 40vdc or while live it would not be a good choice.
 
robbob2112 said:
He stated it was with zero volts/current - i.e. after the breaker was turned off - so no breaking of DC arc required - and pretty much any switch will do after that, particularly one with copper parts, silver contacts and 63a ac rated ... Were he switching higher than the 40vdc or while live it would not be a good choice.
Click to expand...
I said it 'could be" done while not under load because currently there is a solar disconnect. Ideally a device exists that replaces the main solar disconnect, and performs the switching between two target loads.

I have come to the conclusion the solar industry does not may what I am looking for, and I will ave to settle for something "close enough".
 
robbob2112 said:
I like this one :)

OH better, in a box

For either of these get a patch cable for MC4 connectors, cut them in half and attach ring terminals or spade lugs to it.
Click to expand...
Thats the device I mentioned in my first post. There are a million Chinese versions of this switch - sort of the only one of it's kind. I am surprised a solar industry tailored version does not exist.
 
You just need a dual pole dual throw switch with a dc rating
DPDT

The hard part is the voltage and amps with a dc rating. They are a dime a dozen at 12v, but 58v and 20a dc costs

So I am out of ideas and there is little or no demand. The closest I can find is a motor reversing relay for a wench, forklift, etc.
 
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Dustin Henderson said:
Thats the device I mentioned in my first post. There are a million Chinese versions of this switch - sort of the only one of it's kind. I am surprised a solar industry tailored version does not exist.
Click to expand...
Ive got one of those still new in the box from my original generator transfer switch plans. Never got around to using it. I have one similar at my oldest house which I do have acting as a generator transfer switch.
 
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