Need help installing a switch

One of our solar trackers has not been working for a while so I disconnected the light sensor part and dial switch that at one point when it was all working could be turned so that the array would turn LEFT, OFF, RIGHT and AUTO modes.

 In the meantime, want to still be able to move the solar panel array occasionally using the motor until I figure out if its the switch or sensor thats faulty.

The way I have it set up now is taking one of the input lines from the control box which always provides 24+/-  volts from the batteries to the bus bar which feeds the motor. The hot line has a household light switch and an inline fuse. This works great for starting and stopping it left or right but not both.

Reversing the polarity by disconnecting the wires from the bus bar, flippng them and reattaching then makes the motor turn in the opposite direction.
This however is getting old, so I bought a switch that might be able to handle this job. Problem is I'm not sure how to wire it up,

Questions:
Will this switch work for what I want it to do?
This is an AC switch and I'm controlling DC power.




.

Yes, it will work. Disclaimer: I'm not a licensed electrician. No warranties either express or implied.

Basically, all you need to do is reverse the poles on one end of the switch:

Load +          Input +           Load -
         |                     |                    |
        O                     O                   O

        O                     O                   O
         |                     |                    |
Load -            Input -           Load +

Gerry Parent wrote:One of our solar trackers has not been working for a while so I disconnected the light sensor part and dial switch that at one point when it was all working could be turned so that the array would turn LEFT, OFF, RIGHT and AUTO modes.

 In the meantime, want to still be able to move the solar panel array occasionally using the motor until I figure out if its the switch or sensor thats faulty.

The way I have it set up now is taking one of the input lines from the control box which always provides 24+/-  volts from the batteries to the bus bar which feeds the motor. The hot line has a household light switch and an inline fuse. This works great for starting and stopping it left or right but not both.

Reversing the polarity by disconnecting the wires from the bus bar, flippng them and reattaching then makes the motor turn in the opposite direction.
This however is getting old, so I bought a switch that might be able to handle this job. Problem is I'm not sure how to wire it up,

Questions:
Will this switch work for what I want it to do?
This is an AC switch and I'm controlling DC power.




.

yup previous poster nailed it. If it's an AC rated switch I was taught to derate it to 10 percent of rated amperage when using dc. You should try to find a DC rated dpdt (double pole double throw) switch if you will be using it for a length of time. Short term it should be fine. Eventually the arcing from DC current will carbon up the contacts in the switch making it fail or heat up.

Is this what your saying Phil?

David Baillie wrote:
yup previous poster nailed it. If it's an AC rated switch I was taught to derate it to 10 percent of rated amperage when using dc. You should try to find a DC rated dpdt (double pole double throw) switch if you will be using it for a length of time. Short term it should be fine. Eventually the arcing from DC current will carbon up the contacts in the switch making it fail or heat up.

Thats good info to know. Thank you David.

This morning when I took the switch out of the package and tried to move the lever, it was froze. Arggg. So tomorrow when I go to the store, I will look for a DC rated switch as you suggested as a replacement.

Gerry Parent wrote:
Thats good info to know. Thank you David.

This morning when I took the switch out of the package and tried to move the lever, it was froze. Arggg. So tomorrow when I go to the store, I will look for a DC rated switch as you suggested as a replacement.

I suggest looking at marine stores for DC stuff.

Here is a catalog which most likely has useful part numbers. http://www.marinecatalogue.ca/823/

Maybe 12-55019bp

https://www.littelfuse.com/products/switches/toggle-switches/standard-heavy-duty-series/55019_bp.aspx

Or

https://www.littelfuse.com/products/switches/toggle-switches/standard-heavy-duty-series/5592_bx.aspx
which has screws

You've got the gist of it, Gerry. I tend to run mains to the middle and loads across the ends, but what you've drawn will work the same.

As far as the capacity goes, according to the derating info I've looked up, you divide the safe working AC voltage by 10 and use the same current rating, but this is sort of a "redneck reckon" and your results may vary. Of course, if the thing is already mechanically chowdered then this is a moot point.

Given the rating of that switch (10A at 277V AC) I think it would easily handle 10A or so at 24V DC. Not much more without premature pitting of the contacts or even a spectacular one-off light show. There are all sorts of calculations involved in arc formation and for long-term service you really should use a DC-rated device, as David and Jordan advise.

jordan barton wrote:I suggest looking at marine stores for DC stuff.

Here is a catalog which most likely has useful part numbers. http://www.marinecatalogue.ca/823/

Maybe 12-55019bp

https://www.littelfuse.com/products/switches/toggle-switches/standard-heavy-duty-series/55019_bp.aspx

Or

https://www.littelfuse.com/products/switches/toggle-switches/standard-heavy-duty-series/5592_bx.aspx
which has screws

Thank you for the links Jordan!  I will keep them at hand in case the AC switch craps out quicker than expected.

Phil Stevens wrote:You've got the gist of it, Gerry. I tend to run mains to the middle and loads across the ends, but what you've drawn will work the same.

I'm very picture orientated. Is the diagram below what you had in mind?

Yes, a DC switch sounds like its the best way to go for sure, but for now going to just use the readily available AC one and hope it lasts until the real fix can be done.
Lots of other projects calling "Help, Help!" ....so squeaky wheels gets the grease.

EDIT: whoops! In the diagram, one of the load sides polarity needs to be reversed.

You got it. Now go wire it up and see if it smokes!

Had a chance to hook up the switch today.
It worked both ways.... Yipeee!!

Now, what was even more impressive was that I think it even solved the tracking issue.

You see, the previous owner was an engineer who just loved to tinker and often made things way more complicated than necessary. His handy work can be seen all throughout the house...sometimes impressively genius, other times I'm cursing him.

I think he installed the switch to give himself the ability to turn the panel array to the left or right when he wanted to and included  separate power line to do so. The wiring into his rotary switch was very complicated and confusing to me..
So instead of using that line through the switch, I had an inkling to use the power line coming from the tracker motherboard through the switch instead.
Flipping the switch the array started turning  and
as soon as the panels faced the sun, the power was cut by the tracker and the array stopped moving. A few minutes later, it turned a bit more to readjust, proving to me that it was indeed working.

So it is now pretty obvious to me now that a switch was not even necessary as I had assumed all along. If I had hooked that line coming from the tracker directly to the bus bar it would have fixed everything years ago. Doh!

Good side of all this, I learned a little bit more about about switches and that permies people can be really helpful in times of need. Thank you all for your help!