DOL starting 3 Ph Motor and an RCD

[silva.foxx]

hi all and thanks for your help. I have a 3ph socket with a 100mA RCD and it is running fine with that. So, as someone pointed out, the 30mA RCD doesn't get on too well with the VFD. Now that this has happened, I do remember this happening before(a long time ago) and probably should have known better. thanks again.

Does this 100mA RCD satisfy personal safety? If the lead of this portable equipment become damaged and exposes a live conductor, does this 100mA RCD offer correct protection to the poor sod that picks up this cable and receives a new hair-do? .

 

[Darkwood]

Does this 100mA RCD satisfy personal safety? If the lead of this portable equipment become damaged and exposes a live conductor, does this 100mA RCD offer correct protection to the poor sod that picks up this cable and receives a new hair-do? .

This is a common problem with having inverters in portable equipment and really a good all round solution dosnt exist, because leakage is expected to cause nuisance tripping you have to depart from the reg's on this occasion and make it as safe as practically can be done, this includes using cable with earthed braiding and having earth circuit monitors on, the regs are not always practical in every situe but as long as counter measures are taken then youve done you bit.

 

[gerard]

I am going to check the regs but is a 100mA RCD not better than none?! If I make everything as safe as possible then what else can I do?

 

[victory12]

agree , paul. the correct terminology is " shove a megger up it"

Have you taken any IR readings? I can't understand why you've got a RCD on the drive, but never the less it shouldn't trip it. Makes you wonder why your other department gave it away?
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virtual assistant

 

[Robo1401]

If the motor is not faulty then why not just take out the RCD and install a 10A triple pole type C or D mcb? This would allow for the higher starting current and provide the necessary protection needed for this type of circuit?....

 

[gerard]

I want to protect against leakage current and an MCB won't do this. At the moment it is protected with an MCB - still waiting for supplier to get an Si type RCD and this will solve problem - hopefully!

 

[sparkyjames]

What make is the VSD as some are able to disconnect the filters that cause the tripping by a simple jumper inside the terminal cover. This is a risk based procedure based on the sites requirments for 30mA RCD prtection vs EMC issues. New Boy Ducks head and waits for flack:tounge_smile:

 

[gerard]

It's a WEG CS10 - two of them.

 

[silva.foxx]

OK. Lets clarify this for the recent new posters...

The RCD is at the socket that the portable machine is plugged in to.

Gerard has the job in hand by replacing said RCD with a special type.

When he has fitted the new RCD I'm sure he'll post back here with his results.

Clear?

 

[gerard]

OK. Lets clarify this for the recent new posters...

The RCD is at the socket that the portable machine is plugged in to.

Gerard has the job in hand by replacing said RCD with a special type.

When he has fitted the new RCD I'm sure he'll post back here with his results.

Clear?

I sure will. As I said -I'm just waiting for part to come in, there is a delay for some reason.