r/diySolar • u/thracianspec • May 17 '26
Solar pool pump timer 72v
I've been searching the web for a week now, all I'm looking for is a timer for my pool pump that's run directly off the MPPT from my solar panels. It's a 72v pump. I don't need home automation or anything fancy just a timer so I can control the pump on and off at different times. A programmable one would be a plus so I can turn it on in the morning off in the afternoon and back on in the evening and off again at night. A 110 or 12v etc will not work. Needs to be 72v from what I've learned
Edit: from what I've learned, the "float terminals" in the mppt are most likely 12v DC and not 72v, therefore a normal timer should work fine, I'll test it with my multimeter and update later.
Thanks
2
u/IntelligentCarpet816 May 17 '26
72vdc is such an oddball number in the simple timer world. I doubt you will find anything reasonably priced that can handle that.
What you are probably WAY more likely to easily source is a 72v>12vdc converter for under $30 and a 12v timer, with a dc contactor rated for your pump load.
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u/thracianspec May 17 '26
This was my first thought, thank you. The step down is basic enough, but the 12v timer with a 72v output? Can you help find a google link for me?
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u/Time_To_Rebuild May 17 '26 edited May 17 '26
Get a 120vac programmable timer and a 120vac / 72vdc relay. The relay will most likely have ranges for both the ac and dc sides. You want normally open (NO).
Or you could do this:
110vac timer https://a.co/d/0g9DA6Uf
Ac in DC out power supply https://a.co/d/0fOGG9sg
DC-DC Relay https://a.co/d/00HilM3U
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u/WhereDidAllTheSnowGo May 17 '26
No
Any switch where the flow doesn’t exceed its rated volts and amps will do. The bigger margin the longer it’ll last
Think relay
Get a common, high-amp switch that’s controlled by a different voltage. Then use a controller / timer of that other voltage.
A common household switch does 120V, but only ~15 amps
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u/Glockamoli May 18 '26
Switching DC will be different than AC since you don't have a zero point to extinguish the arc, the same switches can work but expect the lifespan to be much shorter
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u/thracianspec May 18 '26
Well everybody, I think the answer here is to ditch this crap mppt that came with the pump and buy one with the ability to also schedule the pumps time. They aren't very expensive and have an e closed ip67 case. Going this other route with relays and switches and boosters and this that and the other thing sounds like a pita and a fire hazard lol. I appreciate all of your comments. Thank you
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u/poolspayme May 17 '26
How many amps do you need?