Hi guys

i upgraded 🤔 from FiveStar 6500W inverter ongrid no solar to two MUST PV1800 Pro 5.2kW inverters with 8 x 550W Canadian Solar Panels totally offgrid. all bought from solarsuppliers

installation went well on a single inverter with panels connected, all visible on SmartESS app.  fans are very loud compared to Fivestar at +2.5kW usage and worse when solar charging.

issue started when i paralleled the inverters. i did do a questionable thing of putting all 8 panels on 1 inverter and 0 on the other due to budget constraints. now i get no more information about solar charging just battery voltage going up or down. inverter screen does show charge light and solar input(Voltage/Apps/kW).

odd thing is the software SolarPowerMonitor 2.81 also does not show MMPT information. it just says stopped but display has correct information🤔

can someone help if there is something needed to be done to view all the information.

i plan to add another 8 Panels to have 8 panels per inverter and but that will be next year late. these panels are giving me more than their spec sometimes usually in the morning 9am to 12pm

System:

Inverter: 2 x MUST PV1800 Pro 5.2kW , 1 MMPT 450V, 18A, 6000W 

Battery: AGM - 200Ah x 12 (600Ah)

Solar: Canadian Solar 550MS 

Solar Safety: 600V DC SPD, 20A Fuse, 500V 20A Breaker

Battery Safety: 200A Breaker--> 125A Fuse -> 125A Breaker 

Output AC Safety: 40A Breaker, 63A Earthleakage, 63A Disconnect

Input AC Grid: Not Used

 

 

 

 

 

 

8 hours ago, Skyelmad said:

Hi guys

i upgraded 🤔 from FiveStar 6500W inverter ongrid no solar to two MUST PV1800 Pro 5.2kW inverters with 8 x 550W Canadian Solar Panels totally offgrid. all bought from solarsuppliers

installation went well on a single inverter with panels connected, all visible on SmartESS app.  fans are very loud compared to Fivestar at +2.5kW usage and worse when solar charging.

issue started when i paralleled the inverters. i did do a questionable thing of putting all 8 panels on 1 inverter and 0 on the other due to budget constraints. now i get no more information about solar charging just battery voltage going up or down. inverter screen does show charge light and solar input(Voltage/Apps/kW).

odd thing is the software SolarPowerMonitor 2.81 also does not show MMPT information. it just says stopped but display has correct information🤔

can someone help if there is something needed to be done to view all the information.

i plan to add another 8 Panels to have 8 panels per inverter and but that will be next year late. these panels are giving me more than their spec sometimes usually in the morning 9am to 12pm

System:

Inverter: 2 x MUST PV1800 Pro 5.2kW , 1 MMPT 450V, 18A, 6000W 

Battery: AGM - 200Ah x 12 (600Ah)

Solar: Canadian Solar 550MS 

Solar Safety: 600V DC SPD, 20A Fuse, 500V 20A Breaker

Battery Safety: 200A Breaker--> 125A Fuse -> 125A Breaker 

Output AC Safety: 40A Breaker, 63A Earthleakage, 63A Disconnect

Input AC Grid: Not Used

 

 

 

 

 

 

As you are not using grid just be careful with the cycling if those batteries. They work great for a few months but not good for off grid daily cycling. 

If you can only cycle down to 12.3V per battery and move as much as possible load to day time. 

Yes the Must happens to be one of the few inverters that start their 1 fan below a set temp. Some others are triggered by increasing temp or a set load or charge rate. 

Sorry I cannot be of any help. 

Edited December 17, 20232 yr by Scorp007

i'm trying but the Wife and kids are stubborn... cooking and bathing late. we usually wake up at 48V (500~700W load at night). i have not reached full battery on solar, usually 51.8V by 6pm never seen float voltage (54.1V). when the app was working i could see it made max 31kWh and min 7kWh  

i have 0.75kW pump that turns on every now and then due to kids using water, probably keeping batteries from reaching full charge. 

i set stop charging at 100% but not sure how it calculates that. 

 

 

1 hour ago, Skyelmad said:

i'm trying but the Wife and kids are stubborn... cooking and bathing late. we usually wake up at 48V (500~700W load at night). i have not reached full battery on solar, usually 51.8V by 6pm never seen float voltage (54.1V). when the app was working i could see it made max 31kWh and min 7kWh  

i have 0.75kW pump that turns on every now and then due to kids using water, probably keeping batteries from reaching full charge. 

i set stop charging at 100% but not sure how it calculates that. 

 

 

That 48V in the morning is too low. Not knowing what uses the 5-700W during the night but I will try to reduce it. 

If you don't gave a pressure tank fit one of 50-100L to reduce the pump from starting at short intervals for small quantities of water used. 

Lead acid batteries not charging full is another suicide act. 

Thanks, I looked into the pressure tank. Decided to go with panels on the 2nd inverter. Installed 4 x 550W , still unbalanced as it's half of the other inverter. 

This has proved to be the best solution as battery now charges fully by 3pm while supporting  normal load.

 

Just a FYI: on SmartESS the inverter now shows solar power but limited to 4 panels 🤔 i guess it needs equal panels but doesn't make sense as panel mounting angles are different anyway thus producing different power.