SCCR tester.

[darekelec]

Dear professionals;
Why does my father, who is an electrician in Eastern Europe, keeps telling me I should get a meter (it's expensive, though) to test SCCR value rather then calculate on paper?
That would make sense cause asking PoCo here for anything (like kVA and Z of xfmr) takes couple of months.
Thx.

 

[GoldDigger]

Are you asking about Available Incident Current (AIC)?
That is what you would be calculating from the transformer info.
Although SCCR for equipment is determined by (often destructive) testing, the AIC from a source cannot be directly tested in the practical world. Instead the tester would have to use a large but limited impulse load to measure the source impedance and from that predict what the current would be into a bolted fault.
I do not know if the NEC even accepts the validity of such measurements for its purposes.

Tapatalk!

 

[ron]

You should post a link to the tester. It seems pretty impractical.

Maybe it induces transients on the source, or some other condition to simulate a small fault.

 

[renosteinke]

I agree with the cynics .... I mean, just because virtually every electrical phenomenon is named after a European .... how can you expect them to know anything about electricity?

 

[darekelec]

I think he wanted me to use SHORT-CIRCUIT LOOP IMPEDANCE METER MZC-310S

http://www.sonel.pl/sites/default/files/en/manuals/en_mzc-310s_v3_2.pdf

that meter costs 2000$
I think also he sent me one much cheaper but it was useless cause they have 230V to ground there and that meter did not give right readings because here is 120V to ground.

I am new to the SCCR and AIC subject so excuse my brevity.

 

[ron]

Interesting. I've never heard of this before. It seems that it will offer L-G information to some extent.

This is a white paper http://www.imeko.org/publications/wc-2003/PWC-2003-TC4-105.pdf

 

[Jraef]

The requirements for needing an SCCR point to standards that dictate how it is to be determined, and nothing in those standards include the use of a tester like this. So although you can use it, that will not qualify as satisfying the standards for determining an SCCR.

 

[Jraef]

Are you asking about Available Incident Current (AIC)?...

I have always understood AIC to mean "Amps Interrupting Capacity" as in "This breaker is rated 65kAIC", to mean it has an interrupting capacity of 65,000 amperes. Available Incident Current makes sense too, I've just never heard that before.

Available FAULT Current (AFC) is sometimes used to mean the same thing as "Available Short-Circuit Current" (officially abbreviated as "SCA" for Short-Circuit Amps), to describe the total current capacity of a system at the point of measurement should there be a bolted fault, and is often used in determining an SCCR. Then "Incedent Energy" is used in determining the potential risk for an Arc Flash event.

 

[jim dungar]

Are you asking about Available Incident Current (AIC)?
That is what you would be calculating from the transformer info.

AIC is short hand for Amps Interrupting Capacity.
AIC applies only to protective devices, like fuses and breakers.
AIC cannot be field calculated, it is a value that comes from the testing of the device.

The AIC of device must be greater than the amount of Short Circuit Amps (SCA) available at its line side terminals.
SCA can be calculated.

AIC and SCCR are well defined terms.
Sadly(?) our industry does not really have a standard method for describing. People tend to like TLA's so we end up with pockets of informal descriptors, like AFC meaning both Available Fault Current and Arcing Fault Current.