12V Fridge Won't Start

[LeighC]

Hello,
Has anyone experienced troubles with hot box start up on Waeco RPD190 / Danfoss BD50?
It can take 30 mins of cutting in & out before it eventually takes keeps going & then works perfectly -18deg.C freezer/ -3deg.C fridge
It only occurs on 1st start above about 25deg C Ambient after doors have been open for a while. Units are brand new. Warranty tech has flushed & done all press. tests OK. tried less 134a etc
Comp.pulls over 10 amps @ 12 volt which is off the chart, cuts out, & flashes a code 3 (Motor start error)(the rotor is locked or the differential pressure is to high >5bar)
Large static air condenser has vertical tubes ( which I can't remember seeing before) Could this be a problem with oil blocking the lower loops?
apparently they only have a .6mm orifice tube.
Have tried a second unit & it does the same thing.
I am only a auto/ AC tech & not really familiar with small mobile/domestic units.
Any help would be greatly appreciated.
Thanks LeighC

[Brian_UK]

Don't know these units but it sounds like the compressor is being overloaded due to the high start up temperatures.

Why are you leaving the door open before starting, are you trying to kill it ?

[taz24]

Hello,

Any help would be greatly appreciated.
Thanks LeighC

I have worked on one of these once before and I found the 12v supply did not have enough power to start the comp in extreme weather conditions. It did not have the torque to turn the motor over.



taz.

[LeighC]

These fridges are used in motorhomes & campervans & the door is left open for storage & closed for start up, so sometimes it can be quite warm inside at commisioning, also flat batteries are a problem as they have low batt. cut out.
Danfoss BD 50 will accept 12 or 24 volt so I tried 24v today & it started up fine, so I think you are on the money, thanks Taz
LeighC

[taz24]

These fridges are used in motorhomes & campervans & the door is left open for storage & closed for start up, so sometimes it can be quite warm inside at commisioning, also flat batteries are a problem as they have low batt. cut out.
Danfoss BD 50 will accept 12 or 24 volt so I tried 24v today & it started up fine, so I think you are on the money, thanks Taz
LeighC

Good to hear it.

The one I worked on was on a canal boat.
But unfortunatly I ended up having to scrap the fridge because the customer thought it would be a good idea to help the defrost with a knife to the evap.

taz.