Max Zs values

[peterfla]

Hi everyone, does anyone know or know where I can find max Zs value for 750A BS88 gG fuses. I did a periodic during a shutdown last week an was rushed of my feet. I can`t find anything on the web and can`t get back in to check the manufacturer.

 

[telectrix]

as a start. i'd use V/I as in 230/5In which gives a value of 230/3750 = 0.06.

 

[peterfla]

I`ve called a couple of manufacturers but they only had values for 630A=0.054 and 800A=0.034 but no values for 750A

 

[Paul.M]

On the same topic, anyone know of the max Zs for a 947-2 1250A???? Got a reading of 0.06 due to the sub station being very close but I need to note the Max? Anyone got any tables?

 

[Jay Sparks]

On the same topic, anyone know of the max Zs for a 947-2 1250A???? Got a reading of 0.06 due to the sub station being very close but I need to note the Max? Anyone got any tables?

Ey up mate, long time no see!!

Why do you need to note the max Zs? Are you using an NICEIC cert? They are the only ones I know of that require the measured and max values. If it's not for a cert and for some other reason, then I can't help.lol


Jay

 

[Paul.M]

Ey up mate, long time no see!!

Why do you need to note the max Zs? Are you using an NICEIC cert? They are the only ones I know of that require the measured and max values. If it's not for a cert and for some other reason, then I can't help.lol


Jay

lol, thanks for not helping Jay :rofl:

NAPIT EIC working under a national building company with their own electrical managers/experts. No stone un-turned kind of thing. Need to log everything, half expect them to ask "what is the purity of the steel on the SWA"!!!! All good fun and keeping me on my toes but it is/has been 10 X worst than the 2391 exam.


If your reading this Mr. M W, you said it first... "It has been emotional". Who is buying the late night fish & chips next time??? (private joke for when he aka the guest/member lurker reads this ). He knows my sense of humor by now, this post will put a smile on his face. Lets see who reads this and/or puts a like on it????

 

[Flanders]

On the same topic, anyone know of the max Zs for a 947-2 1250A???? Got a reading of 0.06 due to the sub station being very close but I need to note the Max? Anyone got any tables?

What make is the mccb i have some tables

 

[Jay Sparks]

Is this any good mate

http://www.sinomation.com/UserFiles/download/1310370348.pdf

Check page 7. I think it's 05ohms max Zs

 

[Paul.M]

What make is the mccb i have some tables

Thank you for your help Flanders. It is Merlin Gerin M12 H1



I'll be honest, this is the first time I've had anything to do with a 1250A breaker (information only, no direct testing or involvement of the connections etc... Above my experience and it was not needed). Any tables would be useful.

 

[ian.settle1]

Ey up mate, long time no see!!

Why do you need to note the max Zs? Are you using an NICEIC cert? They are the only ones I know of that require the measured and max values. If it's not for a cert and for some other reason, then I can't help.lol


Jay

The last company I worked for was carrying out PIR's on an aircraft factory, we had a visit from the NICEIC as part of their annual checks. The guy that came admitted that their certs where not designed for more than installations greater than 100A.

That's why the big companies design their own certs for very large installations

 

[Paul.M]

The last company I worked for was carrying out PIR's on an aircraft factory, we had a visit from the NICEIC as part of their annual checks. The guy that came admitted that their certs where not designed for more than installations greater than 100A.

That's why the big companies design their own certs for very large installations

Cheers Ian, I love that you feel the same about certs above 100A/125A.

Mine are 3 x large(ish) PV installs @ 100Kw+ each. Tapping into and feeding the Grid via the main incoming fuse. This needs to be certificated (AC side) BUT we have Supply and Generation! The standard certs do not account for this form of installation, it is difficult to produce a cert for a 800A, 1000A or 1250A incomer. Schematic diagram needed for each install just to show the experts the layout of the install so everyone can understand it.

Standard certs are rubbish!!!

 

[Flanders]

Thank you for your help Flanders. It is Merlin Gerin M12 H1

View attachment 30558

I'll be honest, this is the first time I've had anything to do with a 1250A breaker (information only, no direct testing or involvement of the connections etc... Above my experience and it was not needed). Any tables would be useful.

For a merlin Gerin STR23SE and a C1251 I have 0.02 ohms on my chart but I think you can change the settings on theMCCB to achieve higher values