no room for Line-Side tap?

[Drivewaybeer]

My engineering plans and electrical permit specify a line-side tap, but the electrician who was scheduled to complete the final wiring has informed me that there is no available space in my 200-amp panel to accommodate the tap. The plans call for a Square D B-Tap model D223NRB Line tap.

Are there any alternatives to replacing the entire panel? I really don't have the budget for that right now even though the panel is an old zinsco. I have attached a photo of the panel where the line-side tap was originally intended to be installed.

Any guidance or suggestions would be greatly appreciated.

 

[Drivewaybeer]

Here's a screen shot of the stamped permit plans

 

[jjww]

might need to shop for another electrician- tho a couple of burndy 3 ways would be pretty tight in there

 

[Drivewaybeer]

To be clear the power comes in from the top and my line diagram shows the tap there...

 

[Koyaanisqatsi]

You appear to have plenty of room on the inner side of your main breaker. Why not put the tap there? It's a lot safer if you do. And a lot more likely to get approved. Line-side taps are a bad deal for a few reasons.

 

[timselectric]

To be clear the power comes in from the top and my line diagram shows the tap there...

Definitely not enough room. Would have to replace the meter/main. And possibly the entire service.

You appear to have plenty of room on the inner side of your main breaker. Why not put the tap there? It's a lot safer if you do. And a lot more likely to get approved. Line-side taps are a bad deal for a few reasons.

Load side tap is limited to 20%.
The line side tap is the only way to get approved above 20%.

 

[Hedges]

What's wrong with even 100% load side tap?

I've got 200A meter & main breaker (only) box, Polaris feeds:
200A sub panel with 200A main breaker
125A sub panel with 100A main breaker
100A fused disconnect

 

[zanydroid]

Why does it need to be a line side tap? There are other options in 705.12 besides 120% rule. I have microinverters adding up to 90A feeding into a 100A panel and service

 

[timselectric]

Why does it need to be a line side tap? There are other options in 705.12 besides 120% rule. I have microinverters adding up to 90A feeding into a 100A panel and service

Are you doing the total breaker route?
That and 120% are the only two that I am barely familiar with.
I say "barely" , because it doesn't really affect me. So, I don't really follow any of it, closely.

 

[timselectric]

What's wrong with even 100% load side tap?

Nothing, if it's an actual load. Because it can't overload the system. "System" , being the conductors and bussing.
But if it's a second source, it can.

 

[Hedges]

Nothing, if it's an actual load. Because it can't overload the system. "System" , being the conductors and bussing.
But if it's a second source, it can.

Try 100A from breaker panel + 100A from PV disconnect on a 2 awg wire.
But feed it through a 100A breaker into a loads panel.

Done as a feeder tap, that should be fine.
Although 200A is available, a 2 awg branch wire is protected with 100A breaker at far end.

Feeder tap rules include 10' max length and in metal conduit.
Although it work work the same without that.

Feeder tap rules allow something smaller, like feeder tap at least 20% (?) of service rating (which isn't even OCP if line side tap!)

I want the wires heavy enough to meet the gauge required for EGC of a circuit having available amperage (200A in this case) to fast trip upstream sources.

 

[timselectric]

Try 100A from breaker panel + 100A from PV disconnect on a 2 awg wire.
But feed it through a 100A breaker into a loads panel.

Done as a feeder tap, that should be fine.
Although 200A is available, a 2 awg branch wire is protected with 100A breaker at far end.

Feeder tap rules include 10' max length and in metal conduit.
Although it work work the same without that.

Feeder tap rules allow something smaller, like feeder tap at least 20% (?) of service rating (which isn't even OCP if line side tap!)

I want the wires heavy enough to meet the gauge required for EGC of a circuit having available amperage (200A in this case) to fast trip upstream sources.

Not really following what you are saying.
But with two sources, you have to make sure that every conductor or bussing can handle what the two sources could put on them.
On a load side tap, the two sources can combine. On a line side tap, they can't.
This is the reason why a load side tap, must be at the opposite end of the panel bussing. To lesson the two sources from fully combining in a single place. But since it still can, there's a limit on the total of the two sources.

 

[Drivewaybeer]

To provide a little more information, my electrical service form PG&E is 200 amp. I have around 6000 watts for solar panels feeding into a Sol-ark 15K. I think the max output of the sol-ark inverter is 62.5 Amps

 

[Drivewaybeer]

any options besides replacing the entire panel and service? I don't think I can even afford that right now. The electrician ballparked 3500 to do that. I'm worried.

 

[zanydroid]

any options besides replacing the entire panel and service? I don't think I can even afford that right now. The electrician ballparked 3500 to do that. I'm worried.

Sum of Breakers / Hawaiian tie in


EG post#3 here

Hawaiian Tie In

Has anybody heard of the term ‘Hawaiian tie in’? We are a solar company in California. We have been told that 'Hawaiian tie in' is common practice out east. With a Hawaiian tie in, we remove all load breakers and put a lug kit to feed a sub where we relocate all house loads. This makes the...

forums.mikeholt.com

And I already said in my previous post that I successfully did this with PG&E with a bigger system size than yours, and smaller service

 

[Offgrid Jungle]

Problem #1 = Zinsco breakers are garbage, unsafe and not covered by some insurance companies if they find out your house has Zinsco breakers. I've replaced hundreds of Zinsco panels and refuse to do a job if the owner "can't afford it".

Problem #2 = Get a new Electrical contractor. They said nothing about this at bid time? Fire them and get someone else.

 

[Hedges]

Not really following what you are saying.
But with two sources, you have to make sure that every conductor or bussing can handle what the two sources could put on them.
On a load side tap, the two sources can combine. On a line side tap, they can't.
This is the reason why a load side tap, must be at the opposite end of the panel bussing. To lesson the two sources from fully combining in a single place. But since it still can, there's a limit on the total of the two sources.

By "load side tap" I don't mean branch breaker installed in breaker panel busbar.

I mean Polaris or insulation piercing connector installed on cable between main breaker (e.g. 100A) and a sub panel with its own main breaker (e.g. 100A).

Let's say the tap goes to a 100A fused disconnect.
And the "Y" shape of wire is 2 awg, so fine for 100A but certainly not 200A.
Not an "E" shape bunch of wires like the busbar in a breaker panel. If it was, backbone of "E" is a busbar, needs to carry sum of current. Body of Polaris serves that purpose in my case.

Thevenin says 100A from grid + 100A from PV = 200A available at intersection of "Y" to go out third leg.
But sub panel has 100A breaker, so that is the most current that can flow.
A 2 awg wire after intersection of "Y" has 200A available to it, but protected by 100A breaker at far end.
That is a "Feeder Tap".

In image below, the extra breakers at near end of run because length 25' > 10'
If they had been 10'and in metal conduit, then "Feeder Tap" and rely on OCP at far end.

For our case, consider "GEN" to be "Inverter", and instead of a transfer switch just wired in parallel.

NEC 240.21B - 25 Ft Feeder Tap Rule - Electric power & transmission & distribution

Do I need to put Breakers for 2 Separate Panel board feeders supplied from load side of Automatic transfer switch with Utility and Stand by generator sources the 2 Panel boards are within 25 Ft from Service entrance ATS (with Stand by generator source) and has their own main breakers as well...

www.eng-tips.com

 

[timselectric]

Thevenin says 100A from grid + 100A from PV = 200A available at intersection of "Y" to go out third leg.
But sub panel has 100A breaker, so that is the most current that can flow.
A 2 awg wire after intersection of "Y" has 200A available to it, but protected by 100A breaker at far end.
That is a "Feeder Tap".

Yes, that's fine because everything is protected at its rating.

For our case, consider "GEN" to be "Inverter", and instead of a transfer switch just wired in parallel.

I would say that the 600a is maybe required, but the 1200a isn't.
Depending on the local jurisdiction.
I only use the 25' distance, when a transformer is the source.
But I don't remember if that's the rule or just a habit.