90.3, Article 480 and 706

[tortuga]

Do Article 480 and 706 ever both apply to an installation where the batteries are listed as an (Energy Storage System)?

Say for example UL9540 but it could be any ESS standard.
Code rules on the 'wiring method' for connecting between an ESS and a disconnect or inverter seem non existent, unless 480.12 applies.

Take for example these 48V batteries:

eFlex 5.4kWh LFP Battery - Fortress Power

Lithium Iron Phosphate Battery Eflex 5.4 KWH is a highly durable, efficient LifeP04 battery that comes with a 10 Year Warranty and remote monitoring features.

www.fortresspower.com

They are designed to have something like 2/0 battery cable ran to them.
The instructions, say a cabinet is optional and depict a battery cable just exiting a wireway this diagram is straight out of the instructions:


In this installation its a fine stand cable that is listed as 600V MTW, exiting the wireway thru a cord grip:
The positive and Negative exit thru separate K/O's:



If 480.12 does not apply is seems like they would have to be in a cabinet.
But the instructions say not required.

Nothing in 706 says 'I modify the code and you can now ignore Article 480' that I can find.
The way I read 90.3 Article 480 applies to all batteries including an energy storage system (ESS).
And when its a listed ESS 706 also applies along with 480 and if there is a conflict with 480, 706 prevails.
What do you all think?
Thanks in advance.

 

[jaggedben]

An ESS sort of by definition doesn't have raw battery output. Many have inverters with AC output, or the DC output is power-elctronically controlled and may shut off if overloaded or disconnected from control wiring. Some are sealed against accessing the batteries other than by the manufacturer. In such cases, and if it's a type of battery that doesn't require ventilation or other such issues addressed in 480, then I don't think 480 applies or can sensibly be applied. 480 applies when you're using raw battery cells and integrating your own charge controllers, inverters, etc., that are not listed together with the batteries as an ESS.

(Theoretically an ESS also can utilize a non-battery energy storage technology - flywheel, say - although admittedly one might not encounter that in a whole career.)

The issue of battery cable wiring methods that you raise has always been one where it seemed to me that common practice wasn't endorsed by the code, although neither explicitly prohibited? Seems like a grey area, and I assume part of the reason these types of systems stay under 50V nominal.

 

[jaggedben]

Say for example UL9540 but it could be any ESS standard.

What other standard is there?

Code rules on the 'wiring method' for connecting between an ESS and a disconnect or inverter seem non existent, unless 480.12 applies.
...

Nah, I think all the normal rules apply. Again, we're talking about AC or DC output from the ESS, not the battery terminals.

 

[tortuga]

Thanks for your input, that clears it up for me regarding the code.
Those Fortress power flex units sure seem more like batteries than any other ESS I have installed.
They output 48 VDC to the inverter, just like a battery would but also have the CAN bus and are listed as an ESS.

 

[tortuga]

What other standard is there?

The IEC CB Scheme (IEC standards) such as IEC standards 62133-2, UN 38.3.
Once you get a product certified under IEC CB you instantly can access 70+ countries and decent majority of the world market.
countries with varying voltage and frequency like Japan not just a 230V 50hz thing.
I personally think UL standards are great for US specific products that are made here and not used elsewhere like EMT or THHN, but we should quit using them for things like and solar / energy storage, as it becomes a tax and just makes our products cost even more, and makes them slower to market.
All the US testing labs actually test to both standards, you just pay extra for a US certification and it takes longer.
Its the same thing for control panels.

 

[jaggedben]

Those Fortress power flex units sure seem more like batteries than any other ESS I have installed.
They output 48 VDC to the inverter, just like a battery would but also have the CAN bus and are listed as an ESS.

Yeah, I agree that units like that are the grayest part of a gray area here. I'm a little unclear on the capabilities of those units to control their own input and output. It seems like the code needs to catch up and make some clarifications but I have not developed any opinions on how it should do that.