Fridge compressor (Danfoss) high amp/h consumption (almost 30amp/h)

[psousa]

Hi!

I know this is a big subject here but I didn't find anything about issues related to high amp/hour consumption, so here I am.

The equipment:
Vitrifrigo C130L DX 06
Danfoss BD35F
I have this unit controller since March 2018: https://www.ebay.com/itm/273083414325?ul_noapp=true
The unit controller on the picture is the old one. (Did you noticed that wires? The blue one with the black and the brown one with the red? I kept it on this new controller but it's starnge! Usually the brown is the negative!)

Since last weekend, when my compressor starts, the panel shows a lot of amp/h consumption.
In the past was consuming only 10-11amps and steady. Now moves from 8 to 27 (I saw 27-28amps few times and 30 once) very fast, which is strange.
I've noticed this because it blew up me 2x10a fuses from the panel. The first one I didn't care. But after the 2nd one on the same weekend I was looking around to the details and it was when I saw these amps on the panel!

After that, checking around, I found the fan is dead (but the unit controller has 12v on F connector). I already ordered a replace one and I'm using external ventilation now.
But the high consumptions keeps moving around (up and down all the time while compressor is working).
The unit controller is new (March/2018).
Fridge is cold enough and the ice compartment is frost.
Thermostat seems to work in spite of I can't see big differences regarding it's position but I didn't tested it really well (just the click on and off). Now it's always on the lowest level, just touching the switch off trigger and the ice compartment is frost, so it's good enough to me.
Tested for one day without the resistor on the thermostat circuit and it defrosts. Amp/h was lower but unsteady anyways and with high peaks, also.
I made the jumper test on the unit controller (connected pins directly to jump the thermostat). The behaviour is the same: high amp/h and fluctuating.
Besides the unit controller replace in March (I did it by myself), nobody touched or changed anything on the system.
Suddenly, last weekend, I had this issue: just the amp/h, everything else seems to be the same.
I don't know if it's related with high temperatures we had, but I don't think so.

I just would like to ask your help pointing me to the right direction. Where should I start? Compressor itself?!? :-O
Unit controller? (I've contacted the seller and he told me it's not possible and considering the symptoms could be the compressor itself). Everyone says the compressor hardly fails, but now I don't know where to start.

Thank you!

 

[Graham376]

Sounds like the compressor to me, our BD50F only draws 7 amps so your 35 should be quite a bit lower. The previous 10-11 amps you quote is way too high.

 

[Daverw]

Have you check for voltage drop, this can raise the compressor running currents quite a lot, with the condenser fan not running and high ambients the compressor will run harder and pull more current anyway but not this much

When compressors fail they either lock and don’t turn and pull loads of current or valves fail and pull very little. Normally not possible for them to pull high due to internal mechanical issues.

Does if blow the fuses straight away or run for a short period?

Regards
Dave

 

[Venus1]

I am not a fridge expert, but I can tell you my experience with my Ozefridge.
My fridge draws about 8 amps (more than it should - that's another story), but you can watch the current increase at startup from about 5A to about 9A, then when the fans come on (the ones thermostatically controlled to cool the compressor), you can watch the current gradually decrease again to 5A as the compressor is cooled by the fans. Then when it's cooled and the fans stop again, you can watch the current gradually rise again to 9A., and the cycle continues.
In other words, current draw seems very dependent on compressor temp, which seems to explain your issue, as you say the fan is found to be dead. (You may have other issues, as the previous current draw seems high anyway?)

 

[Daverw]

I am not a fridge expert, but I can tell you my experience with my Ozefridge.
My fridge draws about 8 amps (more than it should - that's another story), but you can watch the current increase at startup from about 5A to about 9A, then when the fans come on (the ones thermostatically controlled to cool the compressor), you can watch the current gradually decrease again to 5A as the compressor is cooled by the fans. Then when it's cooled and the fans stop again, you can watch the current gradually rise again to 9A., and the cycle continues.
In other words, current draw seems very dependent on compressor temp, which seems to explain your issue, as you say the fan is found to be dead. (You may have other issues, as the previous current draw seems high anyway?)

What you are described if is the compressor load reacting to the condensing pressure, the fan has nothing to do with cooling the compressor but provides air flow over the condenser tube matrix, this is directly related to the air temperature, the lower air temp the more efficient and hench less compressor amps.

 

[Yngmar]

Faulty controller I'd say. Check if the controller box is very hot. BD35F draws around 5A at nominal 12V. That controller you linked does not look like an original Secop/Danfoss one, but a Turkish copy. Likely a bad one. The controller does a lot, including producing the right AC voltages for the compressor motor start/run windings, so most likely the fault is there. It does have the diagnostic LED function of the original though, or at least the documentation claims so. Try connecting a LED as described there and see if it blinks any useful information at you. Failing that, replace with original Secop/Danfoss controller before it murders your compressor motor too (those extra amps are going somewhere).

 

[owen-cox]

This is definitely the case. Replace the fan as it is most likely the high condensing temperature now the air temperatures have gone up that is causing the differences.

What you are described if is the compressor load reacting to the condensing pressure, the fan has nothing to do with cooling the compressor but provides air flow over the condenser tube matrix, this is directly related to the air temperature, the lower air temp the more efficient and hench less compressor amps.

 

[Yngmar]

This is definitely the case. Replace the fan as it is most likely the high condensing temperature now the air temperatures have gone up that is causing the differences.

It should never reach 30A though. The BD35F manual has a handy table for temperature ranges, the maximum power use there is 78.5 Watt, which is under 7A at 12V. The recommended fuse rating is 15A. 30A current draw means something is very, very broken, and it's not just a fan.

Today in a bit over 30°C ambient temperature, our condenser was at 37°C and the compressor at 62°C and the fridge circuit still drew only 5A. That's also a BD35F.

 

[superheat6k]

As already advised, the amps drawn by the compressor will increase with the discharge pressure, and the discharge pressure is a function of the condenser's condensing status, not the compressor, so if the fan stops so does cooling of the condenser, up goes the gas temperature within the condenser along with the compressor discharge pressure, and up goes the amps drawn by the compressor.

This will be considerably exacerbated by the recent high ambient conditions. Ambient air at say 28-30oC around the condenser, but not being moved could easily reach 70oC within the matrix, and with it massive discharge pressures, and currents. The compressor might even have been stalling and / or the motor overloading. Surprised the klixon (bimetallic) overload inside the terminal box didn't click in (I assume the 12v compressors have these).

 

[psousa]

So the Vitrifrigo tech guy came to check and found the problem was with the controller unit from ONE CAR PART LTD (https://www.ebay.com/itm/273083414325?ul_noapp=true), in spite of ONE CAR PART LTD insists which is not possible and they even told me it was a compressor failure!
Less than 3 months working. Garbage! Be aware if you're looking to save money! It will costs you much more!
Confronted with the tech report, they said I should send it back for tests. Sure! It will costs me 60€ just to send it back to the UK! Forget it.
Now I have an original Danfoss/Secop. If you need to buy one, just go for the original one. Looking inside, the board is protected by a transparent silicone-like material which, I believe, will protect it from the toughness of the sea environment. This one (https://www.ebay.com/itm/273083414325?ul_noapp=true) has no protection at all. We can touch everything with your fingers.

 

[pvb]

Ah, another eBay bargain!:disgust:

 

[charles_reed]

Cheap and cheerful parts make one lose sleep, money and utility.
Definitely the control unit - not fit for use.

My BD 35 draws 6 amps on start, 5 amps with the fan on and 4.5amps on economy mode. So did its predecessor and they've a total service life of 27 years. The transformer/controller are the weakest point, and I now always carry a spare - warm beer over a period of 5 weeks in Lesbos forced me to that being the most effective gambit.
It's probably an indication that it's such a quick change design.
here's the manufacturer website - based in S Italy https://www.indelwebastomarine.com/int/

 

[PhilS]

Have you disconnected the faulty fan? If it is mechanically jammed it could be that the stalled fan motor is taking excessive current.