PV signage

Status
Not open for further replies.
M

matt_mackay

Member
Location
Zion National Park, Utah
I'm installing a small PV array directly to the power company. I know warning signs are required but am somewhat confused as to what they should say. The power company calls for a sign that states "Parallel Generation Onsite" citing NEC 110.22 and 430.102. The system contains an array, inverter(with AC and DC breaker), AC disconnect and net meter. What's the signage needed in this application?
Thanks for the help.
 
See Article 690 for examples. If you need a source for signage, one of my clients has enough made that they sell it ...

You will also want a site directory that points to where any other disconnects are located since it sounds like they aren't all at the same location. For example, the utility disconnect, then the PV and inverter AC output disconnects. If there are batteries, you'll also need signage for that.

Basically, PV is an excuse to keep sign making companies fully employed ...
 
bluesmoke...oops said:
I wholeheartedly agree. The notes I had to plaster on my last design were just ridiculous. They want signs everywhere.
Click to expand...

They aren't at all ridiculous. PV is weird and different. It turns out that it is very hard to energize both sides of a breaker (UL 1741), but just turning off the service doesn't mean the building is dead. Killing the power in a battery-backed, grid-interactive system is HARD. The good news is that having a power outage is equally hard -- my monitoring system tells me when the neighbors don't have electricity. That or they are all standing out front (waiting on me to come out and gloat :cool: )

The local fire department came by on a fund raiser / petition drive and I offered to have them over to give them a lesson in "How To Turn Off PV". The guy who stopped by my house had never seen so much electrical gear on a residence -- some of which cannot be turned off, period.

There's the PV / grid interconnect (60A 2P), PV disconnect (60A big red handled gadget), battery DC disconnect (2 x 175A DC), and inverter output (60A 3P -- another big red handled gadget). All those have to be turned off. Even with all that, the 2800 watts DC on the roof is still hot, unless the sun isn't shining. Some arrays make serious voltage even when the sun isn't shining just from street lights or moon shine -- I have a "low voltage" array -- about 110 volts DC open circuit and it makes about 20 volts or so from the street lights and moon shine. Some arrays run close to 600 volts and in Europe they run close to 1000 volts.

There are so many signs because there are so many things to possibly kill you.
 
tallgirl said:
They aren't at all ridiculous. PV is weird and different. It turns out that it is very hard to energize both sides of a breaker (UL 1741), but just turning off the service doesn't mean the building is dead. Killing the power in a battery-backed, grid-interactive system is HARD. The good news is that having a power outage is equally hard -- my monitoring system tells me when the neighbors don't have electricity. That or they are all standing out front (waiting on me to come out and gloat :cool: )

The local fire department came by on a fund raiser / petition drive and I offered to have them over to give them a lesson in "How To Turn Off PV". The guy who stopped by my house had never seen so much electrical gear on a residence -- some of which cannot be turned off, period.

There's the PV / grid interconnect (60A 2P), PV disconnect (60A big red handled gadget), battery DC disconnect (2 x 175A DC), and inverter output (60A 3P -- another big red handled gadget). All those have to be turned off. Even with all that, the 2800 watts DC on the roof is still hot, unless the sun isn't shining. Some arrays make serious voltage even when the sun isn't shining just from street lights or moon shine -- I have a "low voltage" array -- about 110 volts DC open circuit and it makes about 20 volts or so from the street lights and moon shine. Some arrays run close to 600 volts and in Europe they run close to 1000 volts.

There are so many signs because there are so many things to possibly kill you.
Click to expand...

Trust me I know. This system wasn't large enough to power the whole facility so we put in an isolation contactor to cut the inverters off when the gen was on, as it's what the client wanted. But yeah, the DC stuff is going to be lit up anytime there is sun.
 
Status
Not open for further replies.
Top