Level 1 vs Level 2 (NFPA 110 defined) systems and how they relate to the NEC.

[mshields]

Level 1 - systems where a failure of the equipment to perform could result in loss of human life or serious injury

Level 2 - systems where a failure of the equipment to peform is "less critical" to human life and safety.

My question is on the questionable, IMO, definition of Level 2; who is to define what is to be "less critical" to human life?

More importantly what does article 701, Legally required, coincide with. Are these systems Level 1 or Level 2.

If Level 2 implies some criticality to human life then I assume Standby systems are neither Level 1 or Level 2. Is that a true statement?

And if it is, NFPA 110 is entitled Emergency and Standby Power systems yet everything in it falls into one of two Levels neither of which appears to include Standby systems.

Can anyone clarify this for me?

Thanks,

Mike

 

[ron]

I don't know an official answer, but I've generally placed 700 and 701 load associated with Level 1 and 702 associated with Level 2.

 

[steve66]

Not official either, but I believe a 700 or 701 application is a Level 1 installation, unless the AHJ agrees that a level 2 designation is approporate.

I assume neither Level 1 or Level 2 would apply to standby loads, since they are optional loads. So IMO, the designer is free to pick and choose what parts of NFPA 110 they want a standby system to meet.