Hello All,
I searched the forums but could not find an answer and wanted to get some thoughts on the 2020 NEC 230.71 (B) code change. I am currently installing many Square D MPH style meter stacks in a state still under the 2017 NEC. These MPH stacks do not have a single main service disconnecting means and don't seem to meet any of the exceptions under this rule. I would think that in their current design Square D MPH meter stacks would no longer be acceptable. I have not seen any guidance from the manufacturer and would like to some opinions on this.
To further complicate the issue, I was looking through the 2020 NEC Enhanced content and came across the following. Below (from the 2020 NEC Enhanced Content) it states that a main disconnect is not needed and that the 6 separate enclosures would be permitted as the service disconnecting means. Those are separate enclosures or compartments?
"This arrangement does not require a single main service disconnecting means. Six separate enclosures also would be permitted as the service disconnecting means. Some factory-installed switches that disconnect power to ancillary devices that are included as part of listed equipment do not count as one of the six service disconnecting means.
Although the six service disconnect rule for services is retained, the 2020 edition revised the permission for up to six service disconnects to require each disconnecting means to be installed in separate enclosures or separate compartments. This requirement allows an installer/maintainer to operate a single disconnect that de-energizes conductors and circuit parts in the enclosure except for the line side of the disconnecting means. This enhances safety by reducing the likelihood of an incident with energized conductors or circuit parts in the service equipment."
I searched the forums but could not find an answer and wanted to get some thoughts on the 2020 NEC 230.71 (B) code change. I am currently installing many Square D MPH style meter stacks in a state still under the 2017 NEC. These MPH stacks do not have a single main service disconnecting means and don't seem to meet any of the exceptions under this rule. I would think that in their current design Square D MPH meter stacks would no longer be acceptable. I have not seen any guidance from the manufacturer and would like to some opinions on this.
To further complicate the issue, I was looking through the 2020 NEC Enhanced content and came across the following. Below (from the 2020 NEC Enhanced Content) it states that a main disconnect is not needed and that the 6 separate enclosures would be permitted as the service disconnecting means. Those are separate enclosures or compartments?
"This arrangement does not require a single main service disconnecting means. Six separate enclosures also would be permitted as the service disconnecting means. Some factory-installed switches that disconnect power to ancillary devices that are included as part of listed equipment do not count as one of the six service disconnecting means.
Although the six service disconnect rule for services is retained, the 2020 edition revised the permission for up to six service disconnects to require each disconnecting means to be installed in separate enclosures or separate compartments. This requirement allows an installer/maintainer to operate a single disconnect that de-energizes conductors and circuit parts in the enclosure except for the line side of the disconnecting means. This enhances safety by reducing the likelihood of an incident with energized conductors or circuit parts in the service equipment."
