Solar AC Disconnect When Not Visible from the Inverter?

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brycenesbitt

Senior Member
Location
United States
The 2020 code says:

2020 NEC Significant Code Changes Part 4 690 – Solar Photovoltaic (PV) Systems 690.15"
"An equipment disconnecting means shall be permitted to be remote from the equipment where the equipment disconnecting means can be remotely operated from within 3 m (10 ft) of the equipment."


I'm having trouble with the use of the word remote twice. Does this mean the remote control switch for the remote disconnect has to be within 3 meters? Must the control switch just be within 3 meters, or visible from the inverter AND less than 3 meters away? How does someone approaching the inverter know the status of the remote switch? Does "remote" mean that a regular knife switch can be 3 meters away, but out of view?
 
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jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
They are saying that the disconnecting device which de-energizes the inverter can be far away if there is a control for it at the inverter. I this case the device isn't going to be a 'regular knife switch'. It would have to be a switch with a remote actuation feature.
 

Carultch

Senior Member
Location
Massachusetts
One example of a type of switch that this might be, is a shunt trip breaker. Put the push-button at the inverter, put the breaker elsewhere. The breaker is remote from the inverter, the push-button is remote from the breaker, but NOT remote from the inverter. The push-button remotely trips the shunt trip breaker when pressed. The breaker gets to be remote from the inverter, because a person servicing the inverter, can still disconnect the inverter from the grid while standing at the inverter.

The rule used to be that as long as the inverters were readily accessible, it didn't matter how far you made the service person walk to get to the AC breaker or disconnect. It was only when you had your inverters in a not-readily-accessible location (such as the top of a canopy column, or on a rooftop only accessibly by a portable ladder), that the location of its AC disconnecting means mattered. I agree that the NEC needed to require a disconnect you could easily find, rather than leaving open the possibility that it could be hundreds of feet away in another room. The one thing I feel this rule could use, is an exception for a line-up of inverters exceeding 10 ft in length, as long as the AC disconnecting means is grouped. It isn't really an extra safety hazard to have to walk 20 ft instead of 10 ft, as long as it is immediately obvious how to find the panelboard. Grouping makes it immediately obvious, even for 20 ft or 30 ft lineups. Deploying a push-button on half the inverters seems like an unnecessary effort when in practice, the panelboard breakers will be used directly anyway.
 
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pv_n00b

Senior Member
Location
CA, USA
I don't think that a shunt trip breaker meets the requirement for remote operation since the breaker can be reset locally. One of the reasons for the line of sight and 10 ft requirements is so that while someone is working on the inverter they can tell if someone else walks up and tries to turn the disconnect back on. With a shunt trip breaker, there is no way to prevent someone from resetting the breaker out of sight of the worker. The remote operator has to prevent the disconnect from being turned on locally.
 
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