AC Disconnect for Solar panels

[Mike90250]

You need to speak to the NET METERING department. They have a seperate phone # for billing, I'll try to rememeber to look it up tonight.

[russ]

You need to check on this, 'Also, permit wise, I was at Costco last night and they are pushing a Lennox A/C with Andalay Solar combo. I already have A/C but they said that the AC from the Andalay panels could be wired right to my A/C junction box as they do it if it is closer than the main distribution panel. They do it as part of their install of course but it appears to be an easy interface as well for power -- not sure where to get the permit from.'

I am not the electrical engineer or electrician here but it doesn't sound kosher to me.

Russ

[Naptown]

No where in the 2008 NEC is a requirement for an AC disconnect. This is a POCO requirementl. Placement is up to the POCO. Some AHJ's have required disconnects but is redundant on the AC side.

By that statement I mean that as soon ass the meter is pulled and the grid is shut down to the house the inverter shuts down thus making a disconnect a redundancy. If the inverter need to be shut down for maintenance it can be turned off in the panel. Fire departments pull meters.


The only time I could see using an AC disconnect would be if installing a line tap prior to the main disconnect or main breaker in the panel. Yes this is legal. and we do it when running large array's into panels that would exceed the 20% rule.

If running a string inverter however there is a requirement for a DC disconnect, Usually built into the inverter.

[Husketeer]

Im new to Solar PV installs in Canada having just moved here from the UK where we fitted sting inverters and AC disconnects at the panel and attic space and DC disconnects if there was none built into the inverter.
Here in Canada we are fitting Enphase micro inverters behind each module and the location of the AC disconnects varies depending on which area we are installing in. Inside the city limits the inspectors state the disconnects must be either roof mounted next to the panels or at the meter for firefighters to use, however with the micro inveters pulling the meter disconnects the AC to the inverters and hence the DC being converted to AC so the disconnects are merely for maintenance purposes and on the roof they are clearly not accessible either.
Outside of city limits they are happy with the disconnects next to the panel in the mechanical room which makes way more sense.

[vinniethePVtech]

The only time I could see using an AC disconnect would be if installing a line tap prior to the main disconnect or main breaker in the panel. Yes this is legal. and we do it when running large array's into panels that would exceed the 20% rule.

Not to bust your chops. It is amended in 2008, and established in 2011 NEC that an AC disconnect is required at the point of inverter and/or equipment pad. It must be a visible disconnect. If used for line side tap it must be a fuseable visable disconnect. If the AC conductor run distance is longer than 25' from the point of line side tap not load side tap to AC disconnect, an additional overcurrent device must be put in place prior to that TAP.
I'll look up the article and sections tomorrow. I don't know if my NEC PDF will allow me to copy and paste in the forum, but I will try to get it for reference.

I think it might also be copy and pasted on my blueprint cut sheets.