Elect117
Senior Member
- Location
- California
- Occupation
- Engineer E.E. P.E.
For the NEC 2020, 702.5 Exception reads,
"Exception:
Temporary connection of a portable generator without transfer equipment shall be permitted where conditions of maintenance and supervision ensure that only qualified persons service the installation and where the normal supply is physically isolated by a lockable disconnecting means or by disconnection of the normal supply conductors."
TL;DR - How can anyone enforce qualified persons will operate the generator connection and does the installation of a "generator docking station" with a camlock provision mean that it is no longer a temporary generator connection. That the concept of installing such a piece of equipment implies that a generator can be permanently used.
Context:
I was reviewing plans as an AHJ and they intend to use this exception as a means to connect a generator docking station fitted with a camlock. This is a refrigeration building where the utility supply comes to a 4000A multimeter gear, and this company's section is 1600A fused disconnect switch. It would then go on 5 runs of 400kcmil Cu to the generator docking station. From that docking station, they would run 5x400kcmil Cu to the old MSB with a 2500A fused disconnect switch. I included the correction on the 5x400kcmil Cu from the docking station to the 2500A fused disconnect switch because there is no way to verify or ensure that they only use a generator capable of less than 1600A for overcurrent protection on the conductor. So I suggested a change to either 2500A of conductor or replace the 2500A (uncoordinated) fused disconnect.
Utility XFMR->(E) Outside 4000A Pull Section/Multi-Meter Main Switchgear -> (E) 1600A Service Main (Fused Disconnect) -> (E) 5 runs of 400kcmil -> (N) Temp. Generator Docking station with male Camlock connector located outside near main switchgear-> (N) 5 runs of 400kcmil -> (E) Pull Box for splicing into existing -> (E) 5 runs of 400 kcmil-> 2500A fused disconnect in 4000A Board located inside where all of the distribution sections and subpanels are located.
Issue:
My main issue here is with Qualified Person(s). As defined by the NEC,
"One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. (CMP-1)". There is also more on what makes someone qualified in NFPA 70E.
If some guy from building maintenance thinks he understands what he is doing, then they will energize the utility section and other sections of the multimeter panel.
"Exception:
Temporary connection of a portable generator without transfer equipment shall be permitted where conditions of maintenance and supervision ensure that only qualified persons service the installation and where the normal supply is physically isolated by a lockable disconnecting means or by disconnection of the normal supply conductors."
TL;DR - How can anyone enforce qualified persons will operate the generator connection and does the installation of a "generator docking station" with a camlock provision mean that it is no longer a temporary generator connection. That the concept of installing such a piece of equipment implies that a generator can be permanently used.
Context:
I was reviewing plans as an AHJ and they intend to use this exception as a means to connect a generator docking station fitted with a camlock. This is a refrigeration building where the utility supply comes to a 4000A multimeter gear, and this company's section is 1600A fused disconnect switch. It would then go on 5 runs of 400kcmil Cu to the generator docking station. From that docking station, they would run 5x400kcmil Cu to the old MSB with a 2500A fused disconnect switch. I included the correction on the 5x400kcmil Cu from the docking station to the 2500A fused disconnect switch because there is no way to verify or ensure that they only use a generator capable of less than 1600A for overcurrent protection on the conductor. So I suggested a change to either 2500A of conductor or replace the 2500A (uncoordinated) fused disconnect.
Utility XFMR->(E) Outside 4000A Pull Section/Multi-Meter Main Switchgear -> (E) 1600A Service Main (Fused Disconnect) -> (E) 5 runs of 400kcmil -> (N) Temp. Generator Docking station with male Camlock connector located outside near main switchgear-> (N) 5 runs of 400kcmil -> (E) Pull Box for splicing into existing -> (E) 5 runs of 400 kcmil-> 2500A fused disconnect in 4000A Board located inside where all of the distribution sections and subpanels are located.
Issue:
My main issue here is with Qualified Person(s). As defined by the NEC,
"One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. (CMP-1)". There is also more on what makes someone qualified in NFPA 70E.
If some guy from building maintenance thinks he understands what he is doing, then they will energize the utility section and other sections of the multimeter panel.
- How can anyone make sure only qualified persons operate the generator docking station?
- Do I request a letter from the CEO or building owner that a safety program or operations procedure requires that a electrical contractor be called/ onsite to use it?
- Do I ask for a letter from their insurance that they have a workers safety program that is compliant?
- Do I require proof of maintenance contract with a qualified electrician or company?
- Is it out of place for me to even doubt that only qualified persons will service the temporary generator and it's docking station?
- Can a permanently installed camlock provision be considered temporary connection as written in the exception? Is the temporary connection the camlock provision or the generator itself? An receptacle outlet is considered a load when making calculations without anything being plugged in. Shouldn't that same principle be applied for a camlock? Doesn't the installation of a "generator docking station" with the existence of the camlock mean that a generator can be used at any time and for any length of time?
