Victron charger temperature fault

[Pavalijo]

I have a Victron 12/3000/120 multiplus set to charge the 345ah house bank at 60 amps.
It was second hand when I bought it 2 years ago and was professionally installed.
In year one (between S coast uk and Southern Brittany I think it worked faultlessly (don’t remember this problem occurring). In year 2 (NW Spain) the temperature warning light would occasionally flash (on the remote panel) and charging would cease, but this was very occasional, intermittent and charging would resume shortly afterwards. We were home for the really hot weather last year.
This year we have seen the odd temperature fault event but this week, with temperatures into the 30’s the problem is much worse. We saw little charging at all from mains yesterday.
Today is cloudy and raining with inside temperature mid 20’s, but the light is flashing and charging has ceased.
In fault I see the mains on and bulk lights showing constantly and the temperature light flashing.
Earlier I turned the unit off for an hour. I then turned it on and bulk charging resumed for about 20 minutes before going into fault again and charging ceased (as evidenced by the mains ammeter reading).

There is a temperature sensor attached to a negative terminal (tightly) but the batteries are cool and I seem to think (from reading the less than comprehensive manual) that the temperature fault light may relate to the temperature of the Multiplus unit (which is barely warm at the casing).

Can anyone shed any light? I have posted on the Victron Community forum but there have been no response in several hours so far!

There is an electrician in a nearby marina so it will be off to see him if no easy fix!

Fortunately I have enough solar on most days to keep up with consumption - except on grey days like today!
Thanks in advance
Paul

 

[pvb]

There is a temperature sensor attached to a negative terminal (tightly) but the batteries are cool and I seem to think (from reading the less than comprehensive manual) that the temperature fault light may relate to the temperature of the Multiplus unit (which is barely warm at the casing).

The battery temperature sensor's purpose is to adapt the charge voltage according to battery temperature. The specs say the charger will work in temperatures up to 65C, with its fan-assisted cooling. Is your fan running?

 

[Pavalijo]

Thanks - yes, when charging the fan runs. It is in a well ventilated locker. As mentioned, the casing does not feel warm let alone hot!

 

[pvb]

Thanks - yes, when charging the fan runs. It is in a well ventilated locker. As mentioned, the casing does not feel warm let alone hot!

It's possible that the internal temperature sensor is faulty and is triggering a shutdown unnecessarily.

 

[VicS]

It's possible that the internal temperature sensor is faulty and is triggering a shutdown unnecessarily.

The internal temperature sensor appears to relate to the inverter operation, the LED on the front panel flashing to warn that the temperature is approaching a critical level and on continuously to indicate the reason for the inverter shut down.

The OP refers to the LED on the remote control panel but as yet I have not found out anything about the remote panel

It might be worth taking a look at the battery terminal and battery lead on which the battery temperature sensor is mounted. 60 amps is a fair current ( high I would have thought for the battery size) a poor connection on the battery post could well produce enough heat locally to affect the sensor but there does not seem to be any suggestion in the manuals that this would produce any visual warning or shut the cahrger down

 

[pvb]

The internal temperature sensor appears to relate to the inverter operation, the LED on the front panel flashing to warn that the temperature is approaching a critical level and on continuously to indicate the reason for the inverter shut down.

Overheating is more likely under inverter operation, rather than charging, but I imagine the internal sensor will trigger a warning and a shutdown whatever the unit is being asked to do.

 

[Pavalijo]

Thanks for input.
The first thing I did was check and tighten the post on which the sensor is mounted - it was already pretty tight and did not feel at all warm to my fingers!
When I specified the charger I did a fair amount of research and reputable sources (I don’t remember who they were, but I read technical articles on equipment manufacturers sites etc) indicates that 60a is within the recommended range.
The idea of a faulty sensor inside the case makes sense. I will follow that up - there is a chandlery supplying Victron kit who employ a marine electrician a few bays away and he speaks some English!
The fault is showing with the panel set to charger only. The remote panel simply repeats what is on the front of the unit itself so I can turn it on and off and see what is going on without having to access the locker the unit is mounted in - it is nothing too fancy.

 

[mcetap]

You've probably already checked, but isn't it simply a buildup of dust inside the unit, blocking fresh air intake and preventing effective cooling?

 

[[2574]]

I’ve had this problem on my Victron EasyPlus 70A/1600W charger inverter. Probably four or five time over the past decade. The solution, bizarrely, has been to shake the temperature sensor wire which causes the fault to disappear and charging to commence. It works very time I know not why!

 

[Pavalijo]

Thanks - two more things to try in the morning! I did wiggle the sensor wire a bit here in case it could be a cracked wire but not comprehensively.
Just before we went out to dinner the clouds parted and the sun reappeared. The system went on to float and the temperature light went off.
Could this be a battery temperature sensor fault which leads the charger to think (incorrectly) that the batteries are too warm to accept a bulk charge but ok for float?