Fusible disconnect switch Requires to be locked?

Dose a fusible disconnect switch requires to be locked? as it has no dead front and has live parts. I say yes but I am getting kick back from the Solar company's
1. NEC690.4(C)
2. NEC110.26(2) & 110.26(F)
Please give me your thoughts o
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Dose a fusible disconnect switch requires to be locked? as it has no dead front and has live parts. I say yes but I am getting kick back from the Solar company's
1. NEC690.4(C)
2. NEC110.26(2) & 110.26(F)
Please give me your thoughts o
Most (all?) the AHJ's I deal with require the PV disco to be lockable in the OFF position. Is that what you are referring to?
 

tom baker

First Chief Moderator
Staff member
Or do you mean the cover is interlocked with the on off handle.
No code rule that prevents a disconnect from being locked on. I often did this for pump stations.
 
They have what I call utility locks on the doors, behind the door there is no dead front just live parts.
There is lots of equipment that does not have dead fronts - like pretty much every residential loadcenter, bussed gutters, meter sockets. There is no general requirement that equipment be locked. Often there is a POCO requirement that unmetered enclosures be lockable, but that is different.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
There is a change that addresses this in the 2020 code.
690.13 (A) Location. The PV system disconnecting means shall be installed at a readily accessible location. Where disconnecting
means of systems above 30 V are readily accessible to unqualified persons, any enclosure door or hinged cover that exposes live parts when open shall be locked or require a tool to open
.
I don't think that there is anything in the 2017 and earlier codes that would require this.
 
Thank you all for your input, I will keep enforcing locks for all fusible disconnect switch without dead fronts, it doesn't say "shall be locked" but it dose say "shall be protected" and I am the AHJ and no one is getting electricuited in my town, looking forward to the 2020 NEC
 

tom baker

First Chief Moderator
Staff member
Ahh, I see it now. Its solar so fed from line and load. The door is interlocked with the operating handle, when off the door can be open and that only kills the load side.
 

jaggedben

Senior Member
Peter,

Just have them put a ziptie on the locking tab so that it requires a cutting tool to open. No need to make people pay for locks for which the keys will be lost.
 

jaggedben

Senior Member
Ahh, I see it now. Its solar so fed from line and load. The door is interlocked with the operating handle, when off the door can be open and that only kills the load side.
That is just not correct. Interactive inverters shut down voltage when disconnected. It's basically no different than any other equipment disconnect, such as for an air conditioner. They could've called out only disconnects where this is not true, but they didn't.
 

jaggedben

Senior Member
There is a change that addresses this in the 2020 code.

I don't think that there is anything in the 2017 and earlier codes that would require this.
Thanks for pointing that out. Add this to the list of 2020 code changes that I find flabbergasting. Without debating the merits ... (well, I've never heard of anyone ever getting electrocuted because they opened a disconnect door and touched the live parts without knowing what was inside, but aside from that...) ... if there is to be such a requirement it belongs in Article 110. Not 690. There shouldn't be a double standard for solar installers.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
That is just not correct. Interactive inverters shut down voltage when disconnected. It's basically no different than any other equipment disconnect, such as for an air conditioner. They could've called out only disconnects where this is not true, but they didn't.
I'm with you. If you have a safety switch in this situation the line side is connected to the POCO and it has a barrier. The load side is connected to the inverter. When the switch is in the off position the inverter will shut down and there will be no exposed live parts. When the switch is on the door interlock keeps you from opening the door except with a tool.
I think the OP is wrong to require a locked door under the current or 2020 NEC.
 
Thank you all for your input, I will keep enforcing locks for all fusible disconnect switch without dead fronts, it doesn't say "shall be locked" but it dose say "shall be protected" and I am the AHJ and no one is getting electricuited in my town, looking forward to the 2020 NEC
IMO you are abusing your power. You job is not to make people install things the way YOU want them installed.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
That is just not correct. Interactive inverters shut down voltage when disconnected. It's basically no different than any other equipment disconnect, such as for an air conditioner. They could've called out only disconnects where this is not true, but they didn't.
Maybe I am misinterpreting what you say, but when you open a PV disconnect, the side of the switch that is connected to the service is still hot. It is, as you say, the same for a disco for an HVAC system.
 
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