There is no type C for RCD/RCBO spec, type C would be reffering to the MCB over current delay portion of an RCBO - gets very confusing as they are not often specified together. Example you can have a type A RBCO with type C overcurrent properties.Does type 'C' make sense?
Thanks @hermetic - I was thinking about a duff capacitor, because of the way the panel lights, then dims a moment after teh power trips. I flicked off all the other MCB's and tried it, but it stiil tripped out.VFD's have a capacitor array that dumps spike transient voltages to earth, which can trip RCD's BUT, it may be that you have other slight leahages elswhere in the installation that do not add up to the 30mA needed to trip the RCD until you start the lathe? Try turning off everthing or most things on the installation then try thr VFD/ lathe again and see if it still trips.
Phil
That won't cure it as the RCCD works by measuring any difference in the Live and Neutral lines. Any difference is deemed as tracking to earth, wherever that is.Thanks @hermetic - I was thinking about a duff capacitor, because of the way the panel lights, then dims a moment after teh power trips. I flicked off all the other MCB's and tried it, but it stiil tripped out.
Picking up on something @knighty said - if I remove the earth to try it - brainwave - the electric mower extension cable!! Plugged it in - and - it works!!!
So this proves it's something to do with earth leakage. Next thing to try will be a great big earth lead to an earth point away from the RCD....
as above current imbalance. disconecting the earth will make the frame go live and dangerous if its sat on anything insulated it will run ok sit it on anything metalic thats earthed and it will trip and if your in circuit between earth and case and you will fryThat won't cure it as the RCCD works by measuring any difference in the Live and Neutral lines. Any difference is deemed as tracking to earth, wherever that is.
Hmm - OK - so not particularly wanting to die just yet - is there an answer to my problem?as above current imbalance. disconecting the earth will make the frame go live and dangerous if its sat on anything insulated it will run ok sit it on anything metalic thats earthed and it will trip and if your in circuit between earth and case and you will fry
It exceeds 3.5mA, and should be supplied by a Type B RCD (See post #1) which I don't have, and as there are 2 in the supply chain I don't really want to splash the cash if there's a sensible athernative.what is the leakage on the vfd .normaly some the companys specify which rccd to use. some are up to 300 milliamp
Sort extension lead with multimeter in series on the earth wire. Or a sensitive current clamp meter, should give an idea of the leakage.I don't know how to measure the actual leakage, or even if I should be doing that?
Thanks.....but... If I connect the earth wire and switch on (To see the earth leak) , it trips as quickly as you'd hope when an earth fault is present - and as my multimeter won't store 'peaks' I'd be unable to see the values.?Sort extension lead with multimeter in series on the earth wire. Or a sensitive current clamp meter, should give an idea of the leakage.
I'm sorry to say, I don't know?what are your earthing arrangements on the supply is it a tt system or a pme
Rubber gloves and a rubber mat and possibly rubber underwear? HV switchgear days...Hmm - OK - so not particularly wanting to die just yet - is there an answer to my problem?
De-humidifier?My issue is slightly different than yours.
I have 5 VFDs in total. 4 x ABB ACS355 drives and 1 x Bosch Rexroth drive.
I can turn on and run any one of the ABB drives and the Bosch at the same time without any problems.
However, as soos as I turn more than one ABB drive on, the RCD trips. The breaker instantly trips when I try to turn more than one ABB VFD on (not starting a load, just turning the VFD on).
It is not normally a major problem as I don't really need to run more than one VFD at a time. It is just annoying to reset the breaker if I forgot to turn a particular VFD off before I turn another on.
I always wondered if there was something I could do to fix the issue.
I used input suppression on my dual vfd setup at work. I found it tripped just turning them both on.My issue is slightly different than yours.
I have 5 VFDs in total. 4 x ABB ACS355 drives and 1 x Bosch Rexroth drive.
I can turn on and run any one of the ABB drives and the Bosch at the same time without any problems.
However, as soos as I turn more than one ABB drive on, the RCD trips. The breaker instantly trips when I try to turn more than one ABB VFD on (not starting a load, just turning the VFD on).
It is not normally a major problem as I don't really need to run more than one VFD at a time. It is just annoying to reset the breaker if I forgot to turn a particular VFD off before I turn another on.
I always wondered if there was something I could do to fix the issue.