Mobile inverter in offgrid system (magnum mms1012)

bean438
bean438 Registered Users Posts: 3
Hello everyone, I'm brand new here. Before I forget, can you recommend a good multimeter I would need to test, and trouble shoot solar? I've always bought the cheapo units, and would like to finally buy something nice. 
I don't want to over buy for my needs, but also have no problem spending on something on a fluke if need be. 

Now to the the main question. The current cabin has one ac circuit, currently powered by a Honda 2000. We would like to go solar, and use the generator as a backup. 

Niether the circuit, or generator is grounded, and the generator has a floating neutral (no neutral / ground bond)

We need 1200 watt hours per day, and am leaning towards a small 12 volt system, consisting of 4 GC batteries, a couple of panels, and hopefully the magnum mms1012. 

My my concern is how the mms1012 handles "shore" power. The ms series can function as both mobile, and off grid due to the internal neutral / ground transfer switch. 

Does the mms have the same transfer switch? 

The plan is to ground the ac ac circuit in the cabin, and to also bond the generator neutral, and ground the generator. 

Im assuming the mms ac, and dc are isolated, and that the D.C. Side is bonded to the ground terminal, as is the ac side. 

When inverting, the mms operates fully grounded, and "bonded". When it sees genny power, it will lift the ground bond, and since the generator will be grounded , and also bonded, all will be good?

does this all sound right?

i really feel the magnum AE inverters are too big for my needs. It's too bad the mms doesn't have a way to disable the neutral ground bond as the ms series does (4000 models only). 

Do do I understand the difference between an AE inverter and mobile inverter? AE has no bond as we usual provide our own bond, and mobile provides bond with a transfer switch that lifts bond when connected to "shore"?

thank you all

Comments

  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
    As to your first question: I've posted here before that I really like the Klein CL800 meter. It's got a clamp meter for measuring both AC and DC current, has an audible continuity tester, and can grab the max and min measurements so that you can measure inrush current on large inductive loads like motors.  It's here: https://www.amazon.com/gp/product/B019CY4FB4

    I'm not a Magnum expert, so I'll let someone else chime in on the main part of your question.

    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • bean438
    bean438 Registered Users Posts: 3
    Thanks for,the,recommendation horse. That looks like a real nice meter. 
  • bean438
    bean438 Registered Users Posts: 3
    I forgot,to,ask. Any,advantage or,disadvantage with a clamp meter over a dmm?

    looks like the clamp can do everything the damn AND it's a clamp meter too. 
  • nickdearing88
    nickdearing88 Registered Users Posts: 100 ✭✭✭
    I took @Horsefly 's advice on the Klein meter and have been very happy with it so far. I feel it was a good value.
    Current system: 8-100w Renogy panels mono/poly, 2 strings of 4 panels in series - 24v 100Ah AGM Battleborn LiFePO4 batteries - Morningstar MPPT40 CC - 1500W Samlex PSW inverter
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    bean438 said:
    I forgot,to,ask. Any,advantage or,disadvantage with a clamp meter over a dmm?

    looks like the clamp can do everything the damn AND it's a clamp meter too. 


    The advantage is you get what's needed for solar in one meter, if a DMM were chosen you would more than likely be getting a DC clamp on ammeter as well, because it's basically a nesesity for maintaining a system, so kill two birds with one stone.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,036 ✭✭✭✭✭
    The biggest advantage I think is the ability to safely measure much higher current. Most DVM's have a 10 amp limit. There are some that do 20 amps.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.