diy solar

diy solar

New to DIY

2ndsteel

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Joined
Jan 23, 2020
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I have had a SolarEdge 7.2kw system on my house for 5 years. It is fully grid tied. I am in Colorado and getting close to retirement. I would like to install a solar system in my 5thWheel for travel and utilize the expensive components in my shop while I am at home. I’ll spend several days reading through this forum, getting ideas and then I will start posting questions. Larry
 
Hi,
I'm in San jose, Ca, just finised my 48v Off Grid system,
Here is my setup :
- 375w REC solar panel x 9 ( Total 3375 w )
- Midnite Classic 150 Charge controller
- Meritsun 48v/200AH Lifepo4 battery Powerwall ( Total 10Kwh )
- 48v/7000w/120v ac Reliable Inverter
It's been running very nice, power a whole home all day and night
For the total price less than $9000 Usd, pretty good deal,
 
Hi,
I'm in San jose, Ca, just finised my 48v Off Grid system,
Here is my setup :
- 375w REC solar panel x 9 ( Total 3375 w )
- Midnite Classic 150 Charge controller
- Meritsun 48v/200AH Lifepo4 battery Powerwall ( Total 10Kwh )
- 48v/7000w/120v ac Reliable Inverter
It's been running very nice, power a whole home all day and night
For the total price less than $9000 Usd, pretty good deal,
Hi i had purchased a pre-built system similar to yours consisting of 3.1 kw array and a Prebuilt Magnum System 4,400 Watts 48 VDC 120/240VAC
Off-Grid with Magnum MMP-175-30D panel, Classic 150, i was originally running lead acid until they finally died. So I recently also purchased a Meritsun sun 200ah 10kwh battery on alibaba. It seems to work fine but for some reason it won't run my well pump that my previous leads acids with the same system would. I have a 1.5 hp submersible pump 230v dual pole 30 amp breakeron it so has potential for initial starting amps to be close to 30 amps per leg but runs at around 10.5 amps per leg after start up. Thr Meritsun sun battery is rated for 100 amps continuous but for some reason thr battery bms trips a SC PROTECT code. Have any thoughts on this?
 
Hello Gauranga 108,
Congrat on your new system !!. Did you try just to run your pump alone, with 100% SOC ?. You saying that the pump needs to run on 2 LEGS @ 30 Amps @ startup ? so : 30 amps x 2 x 50V = 3000 w @ startup ?
Since your Inverter is 4400w/120v/240v = 2200w/230v , any chance that the Inverter is on the weak side ? when you startup your 3000w pump on a 2200w inverter? - this's just how I feel , I'm not sure it's right or wrong because I'm not familiar with pumps. I ran into SC PROTECT issues many times in the last 10 months. This's what caused it : When the SOC is low ( 20-25 % ) and if I use high power appliances such as 1600w Microwave oven or 1900w hair dryer ....The Inverter needs to pull the Battery hard , make the Battery Voltage drop too fast, and too low voltage causes the inverter stop working. And when I turn off the Inverter then turn it back on again, the whole system is dead !! It scared me a lot on the 1st time
Emoji
, finally I found out it was SC PROTECT, the BMS shut down to protect the Batt. Hope this help, and I wish you make your new Battery work nicely again,
Dien,
P.S : I be able to put 80-85 amps on this Batt with no issues-- SOC is high though, 70-80% or up
 
Hi thanks for the reply
I had tried what you said several times completely shutting off all other loads, with the battery at 100% SOC and during peak sun hours but still shuts down with SC protect code. In regards to the inverter it can continuously run at 4400 watts and peak surge watts of 8500 watts, so i do feel it to be strong enough. Also like I mentioned in previous post that my previous lead acid battery bank that was very much on its last leg so to say utilizing this very same inverter also worked, just prior to this with no modifications other than the battery swap and of course mppt charge controller charge settings. Now that being said maybe the lead acids were not as smart as the lithium bms and its possible the inverter was allowed to draw from the battery for the pumps load more that was good for those batteries possibly damaging them slowly, just a thought. I also did a test of accumulated loads, electric water heater, microwave, toaster etc... adding loads one by one to see how many amps I wss drawing and it shut down at around 85 to 88 amps according to my clamp meter and also the lcd on my inverter. Meritsun also on its lcd shows a current amount, but all was under the apparent 120amps it can continuously put out. I am stumped but I will look into my inverter as the possible problem, thanks again and if you have any more input I would appreciate it.
 
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