No earth

[ohthatshowyoudo]

Hi please can someone assist me.. i have started an inspection on a control circuit and noticed they have not run in an earth on a control circuit they run in a 3 core cable but taped up the green and yellow as live cable. the cable is run under ground from the distribution and is terminated within enclosed plastic houseing so there would be no fault on caseing. please can someone explain to me how i go about protecting this sort of circuit.... or does it require rewire ?

 

[ohthatshowyoudo]

god damm server keeps dropping out................ malcolmmansford.... yes the cable is just control for start stops can i use an rcbo and put warning signs ?

 

[ohthatshowyoudo]

sorry glenspark i was refering to surface mounted plastic s/w i will be more specific next time

 

[malcolmsanford]

It's so difficult to get an handle on your set up.

From the DB board does it go to a local switch isolator of some kind? Does it have a CPC From the board to this.

I take it then that your 3 core cable goes from hopefully the local switch isolator to the motor control panel and from the control panel to the motor? is this right.

The control panel and the buttons etc as Tony said is most likely class II and so Ok, but what is your motor?

 

[ohthatshowyoudo]

the motor them selfs are earthed.... the control stations ie isolator /start stop are wired from the d/b in 3 core were they used g/y --- sw live out to equipment returning control back to db for switching of contactor and thermal overload. db has main earth and all other circuits are earthed.

 

[malcolmsanford]

Then I would not worry to much about it to be honest as Tony said this is something you will see often in control wiring.

 

[GLENNSPARK]

sorry glenspark i was refering to surface mounted plastic s/w i will be more specific next time

no probs mate (i shouldn`t jump the gun)lol!!!

 

[ipf]

I agree Malcolm. 3 wire stop/start control? If so, is it wired in flex, what cca? length of run? what mechanical protection underground?.

 

[ohthatshowyoudo]

thank you all