Commercial Dishwasher-Cable with 2 black and green wires

[atlant]

Hi everyone,

Before I ask my question I would like to Thank each and everyone who contributed to this forum so people like me can read and learn!

I need some help with connecting commercial dishwasher ,I come across cable with 2 black and green wires( I am attaching picture),first I thought that because there is a motor even if I connected wrongly the motor will turn the other way round,but this was only to proof me wrong. I have 20A spur for the dishwasher and no matter what I do it trips the RCD.The dishwasher is second hand so no installers instructions.

Any help and clarity will be much appreciated.

 

[Sparky_Ben]

i would say 1 would be phase and 2 would be neutral, check the internals of the machine as to what is what it maybe be marked in side and check numbers, is there a data plate on the machine some of these can be over 20A more like 32A supply for some.

 

[atlant]

I have tried phase and neutral and sloping around but the effect was the same,trip the RCD,I will be able to check numbers and data plate as soon as tomorrow morning.
Thanks

 

[Big n Daft]

That doesnt sound good.
Check the connections on the machine itself.
If it still trips sounds like a dud machine.
Happy fault finding................

 

[tony mc]

The machine is leaking to earth when switched on & leaking enough to trip your 30 mA RCD (assume 30mA). Even if you have the Line & Neutral connected the wrong way the RCD is still doing its job and detecting a imbalance by tripping.

You need the appliance tested by way Insulation resistance test !!

 

[JD6400]

Just a couple of thoughts , is it 2 phase like some welders , is it a rcbo that you are tripping and it needs to be 32a , or are you sure this is not a Yankee spec machine and needs a transformer ( had this myself a few weeks ago ) .
Other than that you may have a duff one ?

 

[atlant]

Thanks Tomy,I will do Insulation resistance and then lots will come clearer.I was very worried about this two blacks, at some point I tought that this machine may need a transformer or something

 

[tony mc]

Post the make model and ID of machine you never know someone will have info on it.

 

[atlant]

Hi dpelectrical,it is RCD 64A not RCBO,on 32A MCB,Yankee spec machine,this is my worry becouse I have not seen cable like this around,and the numbers on the cable makes sense to be 2 phase,Thanks

 

[Knobhead]

If it is American it will be 220V 2 phase. Their system is 110-0-110.
But you’re looking for an earth fault. Sort that and you will be OK to connect to 230V