Traverse
Member
- Location
- Santa Rosa, CA, USA
Hi all,
(Mods: I am not asking for advice on how to execute my job, I am asking for others' interpretation of code application, safety protocols and input about their purpose.)
This is my first post on the forum, which I had to join after seeing so much good insight. (And yes I have read through discussions similar to my topic.)
I work for a small California based OEM integrator/manufacturer and we design, build, sell, and rent fully self contained portable solar AC/DC systems (some have wheels directly mounted, others are trailer based). With temporary, wheel based, off-grid, low capacity, and a combination of use applications that vary from day to day, how do you regulate this plug and play devices? Our expertise in our niche runs deep, but one thing I continually struggle with is what codes and regulations apply to our various niche applications. Specifically, the conversation about grounding continues to be a grey zone for me. I understand the NEC requirements for grounding and bonding, and I also grok the reasons why they are both needed. But if you can't fit the equipment into an NEC definition, how does the NEC apply in terms of getting an event permit signed at a temporary event? And whether NEC applies or not, does the practice of using a GEC rod actually make anyone safer? Especially when talking about smaller systems capable of producing 2kw-10kw AC max...
Having been in the event industry for a long time I have seen a number of California municipalities treat temporary structures and electrical equipment as though they are permanent and fall under the standards of the building industry, which is rather ridiculous IMO.
My post here is to flesh out and get current code references relating to grounding in the following case scenario:
Single day event, public park, needs temporary event power. The event is environmentally focused, and is opting to use portable solar generator equipment rather than combustion generators. The power will be distributed in the same way that it would be if combustion generators were in use, with UL listed cords plugs and receptacles. The difference being that the source power is harnessed via PV, battery, and inverter. The PV system is designed using UL listed components, but is not itself UL listed.
According to my interpretation, if NEC applies a grounding rod must be driven for each separately derived unit. Which is fine, but what if this were a parking lot or street intersection with no access to earth?
The AWJ is asking for "detailed grounding documentation from the generator manufacturers" to prove grounding. I can do this, even though a diagram doesn't prove grounding only a field test would. Nonetheless I find this request to be erroneous due to a poor understanding of the equipment. They are not generators first of all... and even if they were, has anyone ever heard of a temporary permit requiring such a level of detail from a portable gas/diesel generator supplier? Seems like this AWJ is just trying to justify their high Silicon Valley pay!
Also in practical terms, isn't the point to give current from lightning or a high voltage line somewhere to go, not to prevent a shock hazard resulting from a fault in the circuit. Is that not what circuit breakers are for? Since we aren't dealing with grid line voltage and there isn't any contact with other power systems, this leaves lightning as the only real reason to sweat any of this. If lightning were to strike, wouldn't it more likely strike the massive tent with metal framing next to the small trailer? If lightning is a concern, isn't a lightning rod much more effective at abating danger? Or perhaps lightning arrestors in the inverters? These are thoughts that make me doubt that GECs would even provide much protection at all... Am I totally off here?
In ten years of event production I have never dealt with such rigamarole for an event permit. Usually the fire inspector has some basic safety questions and requirements, but in this case I am also dealing with a building inspector who clearly doesn't understand portable solar power and it's application to temporary event power.
(Mods: I am not asking for advice on how to execute my job, I am asking for others' interpretation of code application, safety protocols and input about their purpose.)
This is my first post on the forum, which I had to join after seeing so much good insight. (And yes I have read through discussions similar to my topic.)
I work for a small California based OEM integrator/manufacturer and we design, build, sell, and rent fully self contained portable solar AC/DC systems (some have wheels directly mounted, others are trailer based). With temporary, wheel based, off-grid, low capacity, and a combination of use applications that vary from day to day, how do you regulate this plug and play devices? Our expertise in our niche runs deep, but one thing I continually struggle with is what codes and regulations apply to our various niche applications. Specifically, the conversation about grounding continues to be a grey zone for me. I understand the NEC requirements for grounding and bonding, and I also grok the reasons why they are both needed. But if you can't fit the equipment into an NEC definition, how does the NEC apply in terms of getting an event permit signed at a temporary event? And whether NEC applies or not, does the practice of using a GEC rod actually make anyone safer? Especially when talking about smaller systems capable of producing 2kw-10kw AC max...
Having been in the event industry for a long time I have seen a number of California municipalities treat temporary structures and electrical equipment as though they are permanent and fall under the standards of the building industry, which is rather ridiculous IMO.
My post here is to flesh out and get current code references relating to grounding in the following case scenario:
Single day event, public park, needs temporary event power. The event is environmentally focused, and is opting to use portable solar generator equipment rather than combustion generators. The power will be distributed in the same way that it would be if combustion generators were in use, with UL listed cords plugs and receptacles. The difference being that the source power is harnessed via PV, battery, and inverter. The PV system is designed using UL listed components, but is not itself UL listed.
According to my interpretation, if NEC applies a grounding rod must be driven for each separately derived unit. Which is fine, but what if this were a parking lot or street intersection with no access to earth?
The AWJ is asking for "detailed grounding documentation from the generator manufacturers" to prove grounding. I can do this, even though a diagram doesn't prove grounding only a field test would. Nonetheless I find this request to be erroneous due to a poor understanding of the equipment. They are not generators first of all... and even if they were, has anyone ever heard of a temporary permit requiring such a level of detail from a portable gas/diesel generator supplier? Seems like this AWJ is just trying to justify their high Silicon Valley pay!
Also in practical terms, isn't the point to give current from lightning or a high voltage line somewhere to go, not to prevent a shock hazard resulting from a fault in the circuit. Is that not what circuit breakers are for? Since we aren't dealing with grid line voltage and there isn't any contact with other power systems, this leaves lightning as the only real reason to sweat any of this. If lightning were to strike, wouldn't it more likely strike the massive tent with metal framing next to the small trailer? If lightning is a concern, isn't a lightning rod much more effective at abating danger? Or perhaps lightning arrestors in the inverters? These are thoughts that make me doubt that GECs would even provide much protection at all... Am I totally off here?
In ten years of event production I have never dealt with such rigamarole for an event permit. Usually the fire inspector has some basic safety questions and requirements, but in this case I am also dealing with a building inspector who clearly doesn't understand portable solar power and it's application to temporary event power.