Tom, this video has been very helpful. Recently I was given a document by Schindler outlining that their max SCCR for their control equipment is 5000A. I do not want to let the smoke out. The available fault current at the equipment feeding the disconnect for this controller is 22kA (give or take). I am being told to "ensure that the available fault current of the building supply at the service switch does not exceed this value." Is this the same thing as protecting this equipment with a fused disconnect? Because the verbiage in that sentence does not make me feel as if that is the case.
I never really considered short circuit current ratings for every small piece of equipment before and don't think I am alone. In cases of many pieces of small equipment it happens to have been listed and made for a typical installation so there's normally no issue. However, it would help the installation community be more aware if there was more standardizing of things and putting it into tables in the NEC or something. We can't afford to make people have to buy standard upon standard and publication upon publication. There's even a fundraiser (informational note) in 240.4 that suggests buying another publication to help with short circuit ratings for wire that is applied within its ampacity!
When is an example where in reality, the X/R ratio is so low as to be of concern? Seems like they go pretty low in tests so I am wondering what installations are actually so low as to need any adjustments. Also, how does the X/R ratio of the utility power source differ in impact from the X/R ratio caused by the power factor of your facility loads?
I’m wondering something. When you protect a Type 2 Surge Protective Device with a 15 amp breaker, what SCCR should be assumed? I see some of them rated in the 100s of kiloamps. So what interrupting capacity of the breaker is needed?
Good talk and useful information, not dry and boring like some others, thank you!
I appreciate that!
Great discussion on SCCR and maximum available fault current.
Another GREAT job Thomas!...Love the analogies as well! Keep them coming.
Thanks! Will do!
This was great. I shared it with colleagues that specify equipment
Awesome!
Amazing explanation. Thanks 👍
Great content. Very useful. Thanks Thomas for what you are doing. God bless you.
My pleasure!
Thanks Tom for these tech talks - great job as always!!!!
Tom, this video has been very helpful.
Recently I was given a document by Schindler outlining that their max SCCR for their control equipment is 5000A. I do not want to let the smoke out. The available fault current at the equipment feeding the disconnect for this controller is 22kA (give or take). I am being told to "ensure that the available fault current of the building supply at the service switch does not exceed this value." Is this the same thing as protecting this equipment with a fused disconnect? Because the verbiage in that sentence does not make me feel as if that is the case.
I never really considered short circuit current ratings for every small piece of equipment before and don't think I am alone. In cases of many pieces of small equipment it happens to have been listed and made for a typical installation so there's normally no issue. However, it would help the installation community be more aware if there was more standardizing of things and putting it into tables in the NEC or something. We can't afford to make people have to buy standard upon standard and publication upon publication. There's even a fundraiser (informational note) in 240.4 that suggests buying another publication to help with short circuit ratings for wire that is applied within its ampacity!
Great information; thanks Tom.
how about the new UL update on SCCR of the Air conditioner on the enclosure mount ?
Love your lessons 💕. I have learnt alot.
I'm so glad!
When is an example where in reality, the X/R ratio is so low as to be of concern? Seems like they go pretty low in tests so I am wondering what installations are actually so low as to need any adjustments.
Also, how does the X/R ratio of the utility power source differ in impact from the X/R ratio caused by the power factor of your facility loads?
I’m wondering something. When you protect a Type 2 Surge Protective Device with a 15 amp breaker, what SCCR should be assumed? I see some of them rated in the 100s of kiloamps. So what interrupting capacity of the breaker is needed?
Very nice tech talking
thanks!