Looking for help. My wife would like me to fix our system for Xmas. Full disclosure: I am not knowledgeable about solar set-ups. Current set-up purchased from discount pond shop. Inverter: Salmac 600watt 24 VDC 120 VAC output. Pump is a Matala MPC-60. We have two DC55-12 deep cycle batteries and 3 200W solar panels charging it. The panels keep the batteries charged and everything works for a while, but once a season the inverter stops working. My suspicion is that the inverter is undersized. The Mátala info says it draws 339watts. Trying to get this for my wife for Xmas. She bought the system from Discount Pond Shop and they replaced the inverter once, but with the same model. Anybody know if my suspicion is correct?Anybody have a recommendation for an inverter that won't bust? I found this one : https://www.amazon.com/Novopal-Inverter-Outlets-Port-16-4-Blenders/dp/B0BP7BH116/ref=sxin_32_pa_sp_phone_search_thematic_sspa?content-id=amzn1.sym.b5d8b92e-4fdc-453f-8f62-8682654ca71a%3Aamzn1.sym.b5d8b92e-4fdc-453f-8f62-8682654ca71a&crid=EB07FDJF6VXP&cv_ct_cx=1500w%2B24vdc%2Binverter&dib=eyJ2IjoiMSJ9.M1Vm7R25HvrPMO1sTdCLRfGbO58VwHtHKzGpd5PsgK7jqMIFFuuSuD4z3r6ra23oTTL6UaeJEk24-JFpNqnZQg.X-AlA1ucvLKbttrX6ATYeDoBddP_aM7aaLpWlnIMD3I&dib_tag=se&keywords=1500w%2B24vdc%2Binverter&pd_rd_i=B088PFM3SY&pd_rd_r=5556749e-084c-4c86-a35b-f0a2d7447e14&pd_rd_w=U7EP5&pd_rd_wg=R7W2y&pf_rd_p=b5d8b92e-4fdc-453f-8f62-8682654ca71a&pf_rd_r=8NGFAHSNK0ACMAX0YA2H&qid=1732900947&sprefix=1500w%2B24vdc%2Binverter%2Caps%2C131&sr=1-1-6024b2a3-78e4-4fed-8fed-e1613be3bcce-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfdGhlbWF0aWM&psc=1&th=1
Hi I am hooking up a similar system, can I ask if you have a low voltage cutoff to protect your batteries or do you rely on the internal low volt cutoff in the inverter?
Pumps in general during start require about 3-4 times the running current requirements. For a 360W motor (3A) the inrush can be 10A, which is over 1KW. It is a short event, but one that inexpensive solar inverters are not typically designed for. When the battery bank is low, and the sun is not out, the inverters are going to be asked to supply the surge while the battery voltage is low, increasing the current draw dramatically from 24V (1000W / 20V, 50A, higher current with a lower voltage). You are experiencing the result. A combination of things will really stress the equipment when the batteries are low. Also when too cold,
The easiest thing to do is prevent the motor/compressor from starting unless there is enough charge in the batteries to deal with the start surge. Even then, the inverter may disagree with the load it is given, it is too close in your system. Bump up the panel count, inverter capacity, and a higher level cutoff with the same load and you should have no worries apart from aging batteries.
I personally do not like 24V DC systems. They should be at least 48V to keep current at reasonable levels for surge, so wire doesn’t need to be huge. If the wiring is insufficient for a 50A draw, bad things will happen at the load end when the voltage droops too low and the motor is stuck in start mode. A sure way to cause a failure. In the example above, 48V current would be 25A rather than 50A all else the same.
Any more than 48V is an outdoor safety issue for electrocution, so that is a good threshold and compromise. I don’t know if the availability and costs of 48V is better or worse. I avoided the pitfalls of a low voltage solar system and opted for a mini inverter topology that goes straight to the grid.
My system has been running great so far and the batteries barely discharge even in our low sun days we've been having here in Ontario.
4x6v batteries - 2x costco trojan knockoffs and 2x AGM odysseys that I got so cheep I could not pass them up even if I ruin them.
Inverter amazon 1000w 24V
2x 500 watt panels 155 watt amazon pump digital timer runs the pump from 8am to 4pm.
keeps the lake open and barely puts a dent in the batteries , I have a low volt cutoff switch but it has never tripped in the last 2 months
if you go with a 48v system youll have to bump up your panels in order to feed the batteries and everything gets exponentially bigger...and more costly...it's surprising how little difference pump sizes actually make to keep the ice off...ie a smaller pump works just about as well as a large pump.
