Battery charger reading...

Blue

Interesting point. I have a smaller 5A Waeco transformer I bought for one of their coolers some time ago. When I then bought a 60l Weaco the bloke from where I bought it said it was too light for continuous use and I needed the larger 6A model, the one for about $100 or so. This I did and we've had no probs.

At the time I had my doubts, however I know the bloke well and accepted his advice. It would appear he was on the ball.

Cheers

Hi Blue, just a guess but the most likely cause for the fuse blowing while using the transformer is that the fridge was pulling more than 5 amps so the transformer put out more current but this would be at a lowering in voltage which in turn caused the fridge to put more amps so the transformer voltage lowered to cater for the increased current requirement. The whole thing is just a down spiralling situation but you get the idea.
In the case of the fridge running of the battery and charger together, the two devices are shearing the load which allows the voltage to remain high and the fridge does not increase it’s current demand. When the fridge cycles off, the charger then charges up the battery again, ready for the next cycle.

Blue,
If I understand correctly, all Weaco fridges use a danfoss compressors. A characteristic of these compressors is that when the compressor starts, they draw a relatively high current, in your case in excess of 6A for a short period of time (1 or 2 seconds) and then settle down to 3.5 amps. This short peak would be enough to blow the fuse if it is a quick blow type.

With regard to the battery charger, if it has an analog meter, (ie moving needle)then it is likely that the meter mechanism won't react fast enough to the short current peak, so that you won't see it.

Hope this helps.

Mal

Spot on Mal! Most appliances draw extra current at start up!

Hi folks, if Blue replaced the 6 amp fuse with a 6 amp circuit breaker, and used it with the 5 amp transformer, the circuit breaker would eventually trip. The surge or spike that occurs when the motor starts would most likely only be the final straw not the cause.
If a 7.5 amp fuse was put in in place of the 6 amp, I think you will find it will still blow. Using a bigger fuse than 7.5 will more than likely result in the transformer being damaged. The 5 amp fuse was there to protect the transformer from continuos overload and has done it’s job.
Under normal circumstances the fuse would not blow.
If the surge that occurs when ever a motor starts was to blow fuses so easily then we would be replacing fuses all over our vehicle all the time.
Fuses will tolerate an amount of surge without blowing, they are more intended to protect against continuos overload and dead shorts.
Cheers

110 lt Waeco. Whoa!!!!

That's like 1/2 of a 44 gallon drum of grog!!

Or, like 5 Jerry cans of grog!!

That, is so cool!!!

I like you.....

Cheers

Wolfie

Hey Blue
I'm thinking of getting a Waeco 110 like yours, what do you think of it, and do you run it as a fridge / freezer or just a fridge?
It'll be my first fridge.