Arc Flash Hazard labeling

[chelin]

Hi,
I'm perfoming an arc flash hazard analysis to a facility which is a data center. After giving them the results they came up with a series of requests. They want me to label each ATS's, disconnect switches and transformers. I know that NEC 110.16 and NFPA 70E 400.11 requires to label switchboards, panelboards, MCC's, meter sockets and industrial control panels... but I have not found anywhere that I need to label the requested equipment. Also, the program that I use (SKM-PTW) does not give me the option for these labels.
What should I do, reply to them that I cannot do it or should I define a bus for each ATS, disconnect and tx to get the labels?
Hope anyone can help me and thank you in advance,
chelin

 

[davidbeach]

Define the bus and provide the labels. Why argue with your client?

 

[Zogzog]

I agree with david, if you dont want the work I will take it off your hands for you

 

[DanDel]

SKM definitely does provide the option for Arc Flash labeling, with dozens of different labels and different ways of outputing the data. What version do you have?

 

[dpc]

Any equipment where the worker could be exposed to live parts or an arcing fault hazard should be labeled.

Have you ever opened up an "ASCO" type ATS? Much scarier inside than any switchboard I've ever seen.

There is nothing in NFPA 70E that restricts what can be labeled.

As David says, you just need to add a bus upstream of each device.

 

[chelin]

I do want the job, the only thing is that I want to do the right thing, I don't want to label something that shouldn't be.

The SKM version is 6.0.... but I haven't found how to label other equipment than buses. The only way would be (for what I know) adding a bus instead of the equipmnet (Ats, disconnect, etc...)

 

[DanDel]

chelin, the SKM model includes the buses to which the ATSs, switches, and transformers are connected. These are typically named for the devices anmd used for the labeling.

For instance, an ATS would have three buses, Normal, Emergency, and Load, all of which could have different Arc Flash energies. You would have the transformer primary and secondary buses, and the bus to which the switch is connected, etc.

 

[davidbeach]

You can't have equipment in SKM without a bus, it may be a node bus and not show up in the flash study; just change it to a regular bus and it should be in your study.

 

[chelin]

yes DanDel, you're right... I usually mark them as bus nodes and do not include them in the labels. What I should do is to give them the name of the downstream equipment and get a label for it, but I still have one question on it; Should I define it from the library and/or give some values to it or just leave it as it comes?

 

[DanDel]

Define what from the library? All of the protective devices must be defined so that their interupting times can be used for the arc flash calculations.

 

[chelin]

Ok, am I confusing everything?
My question is for the bus: If for example I have a disconnect switch and I need a label for it, I need to put a bus (which shows up upstream when I put a disconnect in the oneline), Do I need to define the equipment ratings for that bus or not?

 

[DanDel]

You can still run the arc flash analysis without putting all the data in for each bus.
If you are also running a short circuit study, you will need to input the Short Circuit rating of the bus if you want to analyze the adequacy of the bus momentary ratings.