Auto reclosure

[wangi]

What is the symbol as per IEC for Auto reclosure

 

[inpran]

Wangi,

Its 79.

 

[veritas]

79 is for IEEE/ANSI. Is it also the same for IEC?

 

[wangi]

wish to know how to represent a Auto reclosure in a CAD drawing. what is the symbol used.

 

[veritas]

I lve in the IEC world but have always seen the ANSI symbols used. On rare occasions the actual symbols as per the specific relay are used, e.g. I>, Ie>, etc. My recommendation would be to follow the standard applicable to the drawing. If ANSI symbols are used then 79's your answer for autoreclose. Else use whatever the applicable standard is.

 

[jghrist]

I think the OP means what symbol to draw not what device number to use. I don't know what the IEC symbols are, but if it is an automatic circuit recloser, I'd use a square with an R inside. If it is a reclosing relay, I'd use a circle with a 79 inside. But then I'm in the ANSI world.

 

[pscheshki]

Dear Sirs,
I'm also in the IEC world and I use always IEEE/ANSI numbers for relay protections and automation. There is a difference between IEEE/ANSI and IEC, you can see below.

 

[veritas]

When do you use 64 and when 51G/51N?

Thanks.

 

[ptcabb]

64 is measured with a single phase CT on a earthing point, 51N is through 3I0, 51G I've only seen in ANSI (ok, it IS ANSI, but I haven't sene it used in IEC), but I've been told it refers to a neutral point CT again. So to me 64 = 51G. But 51N is different, measurements wise anyway. Completely the same algorithm behind the measurement though.

Autoreclose looks like so:

 

[ptcabb]

Although the IEC61850 prefix could be different depending on vendor. It's the RREC LN anyway.

 

[veritas]

Too confuse me further, I've seen 64 used for earth leakage relays fed from core balance CT's. But 51G and 51N are used for 3I0 or neutral CT -all depends on the relay.

 

[ptcabb]

In the end they all do the same though, measure if the I0 is above the set threshold value. The IED doesn't really care if it's a core balance CT, neutral point CT or internal / external 3I0 summation.

Actually it doesn't show 50N in that table. Maybe 67 was intended as non time delayed and non stabilized 51N?

 

[wangi]

Thanks to all for the information