sandman.saunders8
Member
- Location
- Tucson, AZ, USA
2011 NEC Section 705 allows for supply side interconnections. However is does not specify how large these connections can be. I read an article in 2012 SolarPro by Mike Holt which states, by the way, that the size of the PV system OCP must be below the rating of the service entrance conductors. This article then goes on to discuss that PV systems are not services and that one may install the 7th disconnect on a given service. This article also has a drawing that shows an OH service to a CT/Term can and then a gutter servicing the six service disconnects. But what about service gear?
My question relates to this type of installation on a service gear without a main switch.
We are looking to put 200A of PV into an 800A rated gear. The gear has a collection of SIX existing disconnects (30A, 100A, three 200A and a 400A). We are hoping to add a 7th disconnect to the gear but have been called on it by an PE electrical engineer and the AHJ plan reviewer stating that we need to follow the 120% rule. This rule clearly only applies to Load side interconnections and would limit us to 160A of PV but only if there was a main at 800A to complete the calculation, which there is not.
If we are installing as described is this not Supply Side (line side)?
How do we size the PV interconnection for Supply side?
Does the 120% rule apply here?
My question relates to this type of installation on a service gear without a main switch.
We are looking to put 200A of PV into an 800A rated gear. The gear has a collection of SIX existing disconnects (30A, 100A, three 200A and a 400A). We are hoping to add a 7th disconnect to the gear but have been called on it by an PE electrical engineer and the AHJ plan reviewer stating that we need to follow the 120% rule. This rule clearly only applies to Load side interconnections and would limit us to 160A of PV but only if there was a main at 800A to complete the calculation, which there is not.
If we are installing as described is this not Supply Side (line side)?
How do we size the PV interconnection for Supply side?
Does the 120% rule apply here?