4 replies to this topic

[Jon R]

Hi All,

I finally plugged my new Grandby (delivered May 2021) into shore power for the first time yesterday so I could use the 120VAC outlet inside. The 120VAC outlet in the front of the sink cabinet doesn't work with all circuit breakers turned on, but I know how to troubleshoot that. The really odd thing that happened was that the DC voltage as registered by my BMV-712 slowly rose higher than I expected.

My Lithium battery was fully charged when I turned on shore power, and initially the battery voltage shown on the BMV-712 was about 14.2 volts (I have the charging voltage limit set to 14.4 on both the Victron MPPT charger and Orion). I noticed the displayed battery voltage was slowly increasing, so I watched it. Over the course of the next minute or so it kept increasing, and I finally shut off the circuit breaker supplying the Iota as it went above 14.8 volts. I did not check the voltage with anything other than the BMV-712.
From looking at the specs of the Iota, which say its no-load voltage is 13.6 volts, I would not have thought it would exceed 13.6. It was as if the Iota was ramping the voltage up to achieve a target bulk charging current. I don't know how it decides whether to behave as a power supply or a charger. It only has one set of 12VDC output terminals.

When I pushed in the kill switch, disconnecting the battery, and then turned the Iota back on, the voltage display on the 12VDC/USB outlet device read the expected 13.4 volts for when it is functioning as a power supply.

Any ideas about what's going on? I may not understand how the Iota is intended to work.

Thanks

Edited by Jon R, 19 August 2021 - 01:49 AM.

[heinphoto]

The Iota that FWC uses has the built in IQ4 charge controller.  It is designed for lead-acid batteries with a bulk charging voltage of 14.8V, absorption 14.2V, and float 13.6v.  So, it sounds like the Iota was doing a charge sequence after you plugged into shore power for the first time.  Unfortunately, you can't change the charging program with the DLS30/IQ4 to match your lithium batteries.  There is a different version of the DLS 30 that allows different IQ4 modules to be plugged in for different battery chemistries.   My understanding is that as long as you don't leave it plugged in to shore power for long periods, it won't damage your lithium batteries.  However it is probably best to let your Victron mppt and solar maintain the battery.

The 120 V outlet is a GFCI outlet, so make sure that it hasn't tripped.

[Jon R]

Thank you for the quick response.  I understand the Iota is not set up for lithium, but was not able to readily find it's charging voltage values.  Thanks for providing those!  That answers that question. 

 

I tried yesterday pushing what appear to be the test and reset buttons on the GFCI outlet, and no change.  It might be defective.  My first step in troubleshooting was going to be to pull the receptacle and see if the wires coming to it have power.  I'll post what the problem was once I figure it out

[Beach]

Lots of good info here. Click on Tech library.

https://www.iotaengi...berOfResults=50

[Jon R]

Thanks, Beach.

The wiring and gfci turned out to be fine. I just did not have a correct understanding of how the 120VAC circuit breaker panel was wired, so in all my various tries at CBs turned on and attempts to reset the gfci outlet, I never actually attempted a gfci reset with power to the gfci. They won’t reset without power.

I was thinking the #1 breaker was for the gfci, but instead it is exactly as it is labeled - a main for the other three breakers. I could see that once I pulled the panel out and looked at the wiring and bus bar on the back. So once I had both the main breaker and the #3 breaker on, and then attempted a gfci reset, it successfully reset and I had power at the outlet. I suspect they tested it at the factory and never reset it.

Edited by Jon R, 19 August 2021 - 01:43 AM.