100a service LST

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windydrew

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Solar Installer/Electrician
Adding solar to a 100a service. Plans call for a LST but there's no access to the conductor outside the home and feeder runs through the wall behind a shower surround. My thought was to add a 8x8 under the meter, add 3 position polaris taps for my 6ga pv conductors. Any code issues here?
The pv disconnect will be within 10ft and is fused. I'll need to bond at the disconnect as well, correct?
 
windydrew said:
Adding solar to a 100a service. Plans call for a LST but there's no access to the conductor outside the home and feeder runs through the wall behind a shower surround. My thought was to add a 8x8 under the meter, add 3 position polaris taps for my 6ga pv conductors. Any code issues here?
The pv disconnect will be within 10ft and is fused. I'll need to bond at the disconnect as well, correct?
Click to expand...
Depending on which code cycle you are on, 230.46 might be an issue for you.
 
ggunn said:
Depending on which code cycle you are on, 230.46 might be an issue for you.
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Which parts, 17 NEC? 110.14 shows set screw splice is permitted. 300.5 is not applicable(underground). 300.13 allows a splice if it's located in a box according to 300.15, and 300.15 is boxes required, which will all be in a box until it runs inside the wall with SE cable.
 
The changes to 230.46 that ggunn is talking about were new in the 2020 NEC. But most actual Polaris brand connectors are fine now.

windydrew said:
Adding solar to a 100a service. Plans call for a LST but there's no access to the conductor outside the home and feeder runs through the wall behind a shower surround. My thought was to add a 8x8 under the meter, add 3 position polaris taps for my 6ga pv conductors. Any code issues here?
The pv disconnect will be within 10ft and is fused. I'll need to bond at the disconnect as well, correct?
Click to expand...

This is rather unclear to me. Does LST stand for line side tap or load side tap? Are you trying to follow the plans or saying you need to do something different?

Under the 2017 grounding and bonding for a supply side connection is pretty vague. Under more recent code cycles they are clearer that you should treat it like another service disconnect, i.e. bring the neutral to the PV disocnnect and bond it to the enclosure and EGC. Just make sure you have a white or green wire going from the PV disconnect back to the service neutral.l, and let your AHJ decide. If a load side connection, keep ground and neutral separate like any other circuit.

An 8x8 is code minimum for 1-1/4" conduits entering, I would suggest going bigger.

In conclusion, lots of potential code issues with details you haven't mentioned, but the general plan is probably fine.
 
jaggedben said:
The changes to 230.46 that ggunn is talking about were new in the 2020 NEC. But most actual Polaris brand connectors are fine now.



This is rather unclear to me. Does LST stand for line side tap or load side tap? Are you trying to follow the plans or saying you need to do something different?

Under the 2017 grounding and bonding for a supply side connection is pretty vague. Under more recent code cycles they are clearer that you should treat it like another service disconnect, i.e. bring the neutral to the PV disocnnect and bond it to the enclosure and EGC. Just make sure you have a white or green wire going from the PV disconnect back to the service neutral.l, and let your AHJ decide. If a load side connection, keep ground and neutral separate like any other circuit.

An 8x8 is code minimum for 1-1/4" conduits entering, I would suggest going bigger.

In conclusion, lots of potential code issues with details you haven't mentioned, but the general plan is probably fine.
Click to expand...
Line side tap, never heard of load side tap.
 
ggunn said:
You can, for example, tap a feeder between a main panel and a subpanel, which would be a load side tap.
Click to expand...
Interesting. Guess I've never ran into it so I'll have to read up on it.

My intention is to run 3 6ga (1 green) conductors from the line side tap in the j box below the meter to the pv production meter and then to the pv disconnect. Then bond at the fused pv disconnect and run 4 (1 green, 1 white) conductors to the inverter. Does that sound right?
 
windydrew said:
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My intention is to run 3 6ga (1 green) conductors from the line side tap in the j box below the meter to the pv production meter and then to the pv disconnect. Then bond at the fused pv disconnect and run 4 (1 green, 1 white) conductors to the inverter. Does that sound right?
Click to expand...

If you're bonding in the disconnect then technically your wire from the j-box to the disco should be white not green. Just like with the existing service disconnect. That said, on the 2017 NEC your AHJ may have their own ideas about green vs. white and bonding, and the code is unclear in Article 705, so not much point in arguing. Some AHJs might want 4-wire from the tap point.

Otherwise sounds fine. Make sure your disco is service rated.
 
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