Weird Charging Problem with Xantrex Charger

[Sailor-man]

I'm having an electrical problem with my charging system. Just replaced the 7-year old CRISTEC charger on my Dufour sailboat with a Xantrex TrueCharge2 40A battery charger.

It works fine except when we run the refrigerator on shore power. When we turn on the fridge, after about 30 mins the charger shows a temperature warning. (According to the manual this indicates the charger itself is overheating). Suggested solution is to confirm fan is working. make sure the unit is in a suitable open area, etc.

The charger fan is working properly and the unit is mounted vertically in a good location. I have tried running the charger under load with all halogen lights and accessaries on except the refrigerator and it works fine. But if I turn on the fridge within 20-30 mins it shows the temp warning.

Thought initially that this might be a faulty charger, but the replacement one does exactly the same.

The refrigerator is a factory installed 12v Frigoboat "Frigomatic Madrid 35F" wired to the panel.

I've had some suggestions that a faulty connection on the AC side could be the problem and to check connections on the panel and refrigerator. I'll look again but everything looks ok there.

Any suggestions or other ideas would be most appreciated.

[mitiempo]

I've installed quite a few of the TrueCharge2 chargers and only ever had one problem - a sticky fan.

Going through the owner's manual the only indicators of thermal shutdown I can see are when the temp and battery leds flash, meaning battery temp is too high.
Are both of these leds flashing? You would have to have a battery temp sensor for this to be indicated. If they are not both flashing which ones are?

If an AC connection is faulty the charger wouldn't be operating properly with the fridge off either.

What is your battery configuration? How many banks do you have? Is the fridge load on the same bank as the halogen lights?

[Sailor-man]

Originally Posted by mitiempo

I've installed quite a few of the TrueCharge2 chargers and only ever had one problem - a sticky fan.

Going through the owner's manual the only indicators of thermal shutdown I can see are when the temp and battery leds flash, meaning battery temp is too high.
Are both of these leds flashing? You would have to have a battery temp sensor for this to be indicated. If they are not both flashing which ones are?

If an AC connection is faulty the charger wouldn't be operating properly with the fridge off either.

What is your battery configuration? How many banks do you have? Is the fridge load on the same bank as the halogen lights?

The flashing lights are the (1) temp light (2) charger light; and (3) warning lights. In the manual, these lights flashing indicate the charger itself is overheating. I do have the temperature sensor but the indicator for the battery has not gone off. The lights, accessories and frig are running off the 2 house batteries. There's one engine battery.

The load for all the lights and accessories (without the frig on is about 40%) on the charger. If I turn all the lights off and just run the frig, it drops to 30% and after about 30 mins I get the warning that the unit is overheating.

I've had one suggestions that there could be a problem on the AC side; but others say this is unlikely. I'm going to check the frig connections next and take some readings and see where it leads me.

If you have any suggestions, let me know.

[mitiempo]

The manuals I downloaded from Xantrex - both installation and owners - have no reference to the warnings you are receiving so the printed manual must be a bit different.

Is the charger wired to the house bank or to both banks?

If you are able in your system try running the fridge off the start battery to see if the same problem occurs. If it works there may be a battery issue - if not the problem lies with the charger. It may eliminate one possibility.

I doubt very much an AC issue - these chargers are very voltage tolerant and it is obviously wired properly.

[Sailor-man]

http://www.xantrex.com/documents/Bat...-01_Rev-B).pdf

Page 3-7

[Spyder]

Check all your "grounds." Are they bright and tightly connected? A bad ground anywhere in the systems cause strange symptoms, including overheats.

[mitiempo]

I see it now - I was looking in troubleshooting farther on.

I agree a loose or bad ground could be the issue. I would go over every wire and connection between the charger and the batteries and the fridge connections as well.