Masterpower UM 3.6 KW and 5.6 KW V4

[larsvonhierblau]

Hi guys, I am on my second unit of Masterpower inverters UM v4. The first one I had was a 5.6 kW Version and I exchanged it for the 3.6 kW version hence I thought the bigger one had an error. But it seems this is a system flaw, hence my second has the same error. I am using this system off-grid with AC IN - PV IN - No Battery (still checking which one to get) - AC Out. Now the issue is that all works fine as it should but the PV INput doesn't show any AMP for the PV array and only volts, therefore also no watt. The same for the AC output. No AMP is showing but volt and every attached load seem to work just fine. I bought now two separate current measurement devices, which should measure AC IN and AC Out so I can subtract AC In from the AC Out number and should know how much KW/h the PV did. however, i found this odd that both units have the same no-show for the AMPS. I wonder if this might have something to do with the not connected battery? I also saw in the box of the inverter this extra DC fuse (blade) and wondered what this is for hence nothing is written in the manual.

I hope someone can help me out here. Would be really appreciated.

 

[MrThisIsME]

Briefly looking at the manual for the unit, I see no mention or assumption that the unit would run without a battery. Most (that I have seen) AIO units require a battery. Growatt for example will not start without DC.

As the manual is not clear, call the vendor or the manufacture as the case may be?

 

[larsvonhierblau]

Hi and thanks for the answer. Ah I called the importer in spain but they just pushed me to another number and never picked up on that but wrote me a message that they can't tell me anything at the moment. However, there is a section in the manual: https://www.masterbattery.es/manuales/Omega_UM-v4.pdf page 38 last box - Line Mode in SUB. Its just odd because both units show this issue in the same way.

 

[MrThisIsME]

Read that on line 38 as you mentioned. Seems to imply that it can run without a battery. The manual is written somewhat better than most Chinesish manuals. The interface seems a little like a Growatt hence I thought it would need a battery. Irregardless, I would think it might be a glitch in the firmware. They might of never tested without a batter, crude guess.

Still able to return and find a unit with some better support, even if a forum as such here?

 

[larsvonhierblau]

I figured it out and I guess the previous unit was also ok. Hence I was just building the system I only tried it with a small load like 30 Watt fan. However, I tried it today with higher loads such as a water cooker and so on. It seems the unit needs around 100 Watt load or so to actually let the measurement kick in. I tested it over several hours and it worked flawlessly.