Shut off 3 phase supply

G

Guest 004

• Apr 23, 2013

• #1

I need a solution for a problem I have, just cant seem to think at the moment.

I need to shut off a 3 phase supply when a supply to one phase has failed? Now I am thinking 4 pole contactor, but I am not sure of how to monitor the 3 individual phases on 1 control circuit? 3 control circuits perhaps?

 

OP

G

Gage

• Apr 23, 2013

• #2

Define failed... I'm probably missing something here because I'm zzzz but...3 Phase MCB?...

 

H

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• Apr 23, 2013

• #3

use 3 single pole contactors with the 3 phases operating a (A1&A2) coil each, with the L1&L2 contacts in each wired in series to control the coil in a 4 pole contactor. Does that make sense?

 

OP

G

Guest 004

• Apr 23, 2013

• #4

^ need to elaborate a little on that HT

 

OP

G

Guest 004

• Apr 23, 2013

• #5

Gage said:

Define failed... I'm probably missing something here because I'm zzzz but...3 Phase MCB?...

Click to expand...

Incoming supply where 1 phase goes down

 

OP

G

Guest 004

• Apr 23, 2013

• #6

@HT

Thinking maybe 3 double pole contactors, with one pole wired in series to feed a 4 pole contactor?

Is that what you meant?

 

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• Apr 23, 2013

• #7

MrEnigma said:

@HT

Thinking maybe 3 double pole contactors, with one pole wired in series to feed a 4 pole contactor?

Is that what you meant?

Click to expand...

Pretty much yes

 

Hawk81

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• Apr 23, 2013

• #8

What about a phase failure relay controlling the contactor http://stevenengineering.com/Tech_Support/PDFs/45RPHS.pdf

 

OP

G

Guest 004

• Apr 23, 2013

• #9

^ thats the kiddy, nice and small as well.

 

OP

K

KINKY

• Apr 23, 2013

• #10

gage said:

define failed... I'm probably missing something here because i'm zzzz but...3 phase mcb?...

Click to expand...

fail....

 

OP

G

Guest 004

• Apr 23, 2013

• #11

^ ok buddy were are here to help people, not to dis

 

D Skelton

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• Apr 23, 2013

• #12

Forgive my rather rudimentary drawing but this is essentially what you want to do:

 

Last edited: Apr 23, 2013

OP

G

Guest 004

• Apr 23, 2013

• #13

^ thanks DS

but I do think my OP has been awerserd by post no. 8

thanks guys


Can we let this run for a couple of of days, before a mod closes it down (happy with that), but pretty sure I have a good answer.

Thanks again hawk

 

D Skelton

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• Apr 23, 2013

• #14

Essentially, in its simplest form my drawing is what a phase faliure relay does

You don't neccessarily need a phase faliure relay so I'd go with whichever option is cheapest.

 

OP

E

Engineer54

• Apr 24, 2013

• #15

From the OP i'm still not sure what he's trying to do. If all he wants to do is shut down a 3 phase supply when losing a phase, say due to a fault down stream, and the supply has fuse over current protective devices, then all that's required is to replace the fuses with a multi phase MCB/MCCB. Anyway if he's happy that he's found a solution in the way of a phase failure relay, all's good!! lol!!


One of the reasons i don't like fuse protection for poly phase motors, unless those fuses are of the striker release type, where when any fuse ruptures, is releases a striker to disconnect all the phases.