question

b380 avatar image
b380 asked

Keurig Causing MP-II "Pulsing" Buzz, Flickering Lights, Erratic Switching of Modes

TLDR; My MultiPlus II is (somewhat intermittently - certainly more often that not) doing what you see in the below videos when I run my Keurig coffee maker. Can I fix this? Is it going to damage my electrical system? Why would this happen intermittently?

Video 1: https://photos.app.goo.gl/jDyTQ5EHZSjGWrtB8

Video 2: https://photos.app.goo.gl/bjRkDAiwApQ1yrQr7


Hi all,

The past couple of days when I brew coffee with my Keurig I notice the following:

  • MultiPlus almost always emitts an audible pulsing buzz (see Video 1 link below)
  • 12v lights flicker in sync with pulsing buzz
  • Sometimes MultiPlus lights bounce between "Absorption" and "Inverter On"
  • GX Touch50 display shows inverter looping between "Float" then "Assisting" and sometimes even goes into "Passthru" and I see very weird power readings, sometimes much lower than what the Keurig would normally pull (~1500w). I've even seen negative grid power as if there was a back feed?


Diagnostics:

  • Unplugged shore power and ran with inverter only. No resolve.
    • Seems to do a bit better when disconnected, but it's definitely still happening.
  • Tested other receptacles across the RV with similar results.
  • Validated wiring at receptacle is properly secured and wired correctly
  • Validated wiring at breaker is properly secured and wired correctly
  • Ran comparable loads on the same receptacle (while on and off shore power) with no issues (hair dryer)
  • Ran comparable loads on other breakers from the same leg (while on and off shore power) with no issue (AC or microwave supplemented with smaller loads like fans or computers)
  • Googled the issue and found out about this TRIAC technology that causes this Keurig (and some other) coffee maker heating elements to pulse 10-20x per second often causing light flickering even in homes


Based on my diagnostics and research I think I can conclude the coffee maker is working as intended and it seems that my equipment is still in good shape given that everything else works fine except the Keurig. What's happening is an unfortunate effect of this TRIAC technology that is apparently magnified with inverters of all kinds. However, this all begs a few questions:

  1. Is there anything I can do to fix what you saw in the videos?
  2. Is this going to cause damage to my inverter or electrical system in general?
  3. Why would this happen intermittently and why is it that when it does happen it is often at different magnitudes?


Relevant Electrical Components:

Victron MultiPlus-II 12v 3000w (4/0 wiring to Lynx and battery bank and 6/4 SOOW to panel)

Victron 150/100 MPPT

Victron Cerbo GX/GX Touch50

Victron Lynx Distributor

(6) 100ah Battleborn LiFePO4 (4/0 wiring)


Thank you all!

Multiplus-II
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2 Answers
mvas avatar image
mvas answered ·

Connect the Keurig to a dedicated 2000 Watt dc-ac inverter. Pulsing a 1500 watt load at 20 times per second, on a shared inverter, can be problematic. A 20hz flickering light is very annoying. I am guessing, the intermittent nature is due to synchronization between the frequency of the Keurig and the frequency of the inverter. An alternate solution ... buy a different coffee maker. Or buy a much larger Multi-Plus inverter. You have found a device that is border-line useable with your small dc-ac inverter

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b380 avatar image
b380 answered ·

Thank you for the response. For what it's worth, when I make coffee I have a max load of 300w as it's early in the morning. Based on some reading, this may be an issue for ANY inverter.


But at the end of the day, my (perhaps ignorant) opinion is it is something Victron can solve with a software update. If I'm connected to 30A shore power with nothing more than a couple of small 12v lights on in addition to the coffee maker (max load of 1,800W, <60% of rated power) why doesn't the inverter pass through? It shouldn't even be kicking on, yet it is attempting to PowerAssist unnecessarily.


As a future reference for those looking for a band-aid fix, if you're on shore power you can set the inverter to "Charge Only" and it works just fine.

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