SPDs required on EM inverters?

[gh0st]

If an emergency lighting inverter was provided with integral distribution (ex. 20A/1P breakers), would the inverter be designated as a "Panelboard". If so, and if the inverter was providing power for life safety lighting loads, I would believe that the inverter would either need to be UL 1449 listed or be provided with a UL 1449 SPD. Correct???

Is it also safe to assume that if an inverter did not have onboard distribution but was simply feeding a standard panelboard, only the panelboard would need to be provided with a listed SPD?

Some code references:

285.6 Listing. An SPD shall be a listed device. Ul 1449, Standard for Surge Protective Devices......

700.8 Surge Protection. A listed SPD shall be installed in or on all emergency systems switchboards and panelboards.

The Code defines a panel board in a few ways.
1) Panelboard: A single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in or against a wall, partition, or other support; and accessible only from the front.
2) ....A panelboard is an electrical assembly designed to be placed in a cabinet or cutout box.

Thanks.

 

[paulengr]

Yes but it all depends on if this is an emergency system or not. See also NFPA 110 that gets into a lot more detail. NFPA 101 Lufe Safety Systems is the actual enabling Code that triggers this.

As an example usually you need lighted exit signs but there are glow-in-the-dark sticker signs that meet this requirement. If the distance is a long ways or stairwells are involved you typically need lighting. Battery powered lights on the exit signs is usually all you need. This is far cheaper than a centralized backup system. But beyond a certain distance such as in a very large plant it may require for instance a lighted and ventilated hallway for escape to shorten the distance. This gets beyond basic battery power.

Aside from this you will see some emergency or security services go down this rabbit hole voluntarily. Think “fallout shelter” like in a chemical plant or government security. Or a hospital operating room area where even though they have manual backups typically they go for the critical emergency option. Then you find an entire backup power system with redundancy including the testing and maintenance requirements.

In terms of implementation NEC 700 is relatively easy. NFPA 110 is not. So be careful about whether this is truly a critical emergency system or merely a backup system. And just because you can get dual source lighting doesn’t necessarily mean it’s a good idea to use it.

I’ve run into customers that often say they want emergency systems but when you look they aren’t NFPA 110 compliant, and they aren’t triggering anything in NFPA 101. So then you know it’s just a standard backup system and you can just ask how far they want to take it.

That being said surge arresters are now required in most panels because AFCIs aren’t properly rated for the service they are in. The “solution” is requiring a surge arrester instead of requiring higher surge ratings.

 

[steve66]

I would consider an emergency lighting inverter as being covered under its own UL924 listing. Therefore, its not a panelboard since its listed as something else.