Multiplus2 Installation and Maintenance

[SD McCart]

Hello all. This is a public service announcement regarding maintenance on the MP2. (long post warning) This may have been covered before but I think it is a good reminder to check the wiring on your MP2 as a regular part of the units maintenance. It appears I had a loose input wire (black 6AWG) which melted the terminal block, filled my basement with smoke, could have caused a serious fire and it ruined my MP2. I will add photos below. I received my MP2 in April 2023 and this happened in January 2024. The input wire I used is what came in the camper, the stranded wire that originally went to the back of the breaker box. I made some mistakes which fortunately only cost me money and time. I did not strip my wire long enough, I did not put a longer length of wire in the base of the MP2 and do a proper tug test. I did not perform regular maintenance/tug test on the wiring. So this expense of time and money is on me. After melting my terminal block less than two weeks into a three month trip I contacted Neil on this site whose advice and guidance was priceless and kept us going. Thank you Neil! (I will try to add links to the video’s and equipment Neil sent me) He told me to get at least 6AWG insulated wire splice connectors so I could connect the wire from the input of the MP2 to the wire on the output of the MP2. He then instructed me to get my lithium converter and run the appropriate wires from the converter to the Lynx and plug it in. This basically put the wiring back to the way it was when I purchased the camper. I did this, after having my converter and extra wire shipped to me, and I was back in business, charging my four batteries and having a fully functioning camper. I will keep these connectors and converter in my unit from now on. I filed a warranty claim with Inverters R US and did not hear back from them in a timely manner. Neil assisted by contacting Current Connected who filed my claim and within days heard back from Victron that this was not covered under warranty due to my installation error but they would meet me half way on a new MP2 which I received and installed correctly. I did use the fine stranded wire and ferrules as recommended in one of the videos. The Current Connected rep as recommended this wire. I hope this post, and more so the videos, are helpful for installing an MP2 or similar unit and its maintenance.

Installation Videos:
Victron MultiPlus-II Inverter: Step-by-Step AC Output/Input Connection Wiring with a Spring Terminal (youtube.com)

Victron Multiplus II Wiring Tutorial (youtube.com)

Wire splice connectors or something similar:
OhLectric Electrical Power Cable Connectors - Single Entry Splice - Black Insulated Vinyl Coated Wire - 2-14 Wire Range - Slotted Allen Hex - Aluminum Connector for CU9AL Wires - Pack of 4 - OL-67604: Amazon.com: Tools & Home Improvement

[ncitro]

Glad it worked out Scott, I know it was a long road. Definitely good for everyone to keep in mind.

[Jlawles2]

That truly is not good. Glad nothing other than the device was damaged. With the fine stranded wire you will find it's much easier to put the strain loops in making it easier to check later (that list of things to check on a camper just keeps getting longer).

I do not have an inverter but, I am not a proponent of the spring connections. I prefer good old fashioned screw terminals or lugs. Wish there was an option for that on the device.

[ncitro]

I agree, I am not a huge fan of those connectors. The fact that a dealer (linked above) released a video on the best way to insert the wires tells me it should be better. That said the inverter, its software, and the integration to the rest of the Victron ecosystem is amazing. In my mind the MPII is still one of the best products out there for our use case, you just need to be very careful in how its installed, and apparently given his response from his dealer, research your dealer well and be confident they will stand by you.