Relocation of Type 2 SPD

[Bluetec]

Greetings,

I have a single-family dwelling supplied by primary service and a standby generator with a 200-amp transfer switch: I am upgrading the 120V breakers in a 200-amp main lug CB panel (surface mount inside wall). It is supplied by 200-amp outside meter/load panel (one 200-amp breaker disconnect) and the standby generator transfer switch if the primary service fails. The transfer switch does not provide any load center capability for circuit breakers.

I am upgrading the 120V breakers in the inside panel to AFCI/GFCI breakers. There is an EATON CHSPT2ULTRA installed at the breaker panel. The breaker connected to the SPD is a Siemens tandem 15/5050/15 breaker. I have to split the circuit into two 15-amp dual function breakers for AFCI/GFCI protection. There is not enough room in the cabinet for a double-pole 50-amp breaker and separate 15amp breakers. I have not been able to find the new Siemens Tandem Combination AFCI breakers that I could use to make space for the 50-amp double pole breaker.

I have decided to relocate the Type 2 SPD to the outside 200-amp meter/load center and install a 50-amp breaker in the panel and attach the SPD to the outside of the panel trough a 1/2" conduit knockout.

I cannot find anything in the 2020 NEC that details SPD protection when a Type 2 SPD is on the load side of the meter/load panel and a transfer switch is between the meter/load center and the main inside panel. The SPD should be on the load side of both sources of power but I don't have that solution. Does anyone have a suggestion on how to provide surge protection when the generator is powered on and supplying power to the inside panel? Does it require an adjacent subpanel, powered by the main, inside, CB panel, with breakers for the Type 2 SPD and the two 15-amp circuits?

One more question, please: If the Type 2 SPD is connected to an outside panel, does it need GFCI protection?

 

[tom baker]

"details SPD protection when a Type 2 SPD"
If I follow your question, SPD protection is as required by the mfg, often its a 30 amp 2 pole breaker.
Can you put the SPD on the inside CB panel, thats allowed by Art 230

 

[texie]

"details SPD protection when a Type 2 SPD"
If I follow your question, SPD protection is as required by the mfg, often its a 30 amp 2 pole breaker.
Can you put the SPD on the inside CB panel, thats allowed by Art 230

I think the OP is raising an issue that the CMP did not foresee or maybe they deem it a non issue. 230.67 Exception says the SPD can be "at each next level distribution". Not mentioned is what if you have equipment in the feeder between the main and the first panel such as a transfer switch.

 

[Bluetec]

Thank you, texie, for putting my dilemma into simple terms. EATON suggests the CHSPT2ULTRA be connected to a 50amp breaker.

Generac and Eaton offer automatic transfer switches with built-in load centers with up to 60 circuits but that would be a costly endeavor to replace the transfer switch. I found this quote on the NEMA Surge Protection Institute site, concerning the "Correct Installation of Hard-Wired Surge Protection Device":

"SPDs should be connected through an appropriately rated circuit breaker not into the main lugs of the panel. Where circuit breakers are unavailable or impractical, a fused disconnect switch should be used to connect to the lines and facilitate servicing of the SPD."

In between the generator and the transfer switch is a Siemens 100amp fusible disconnect switch. If I switched the single-wire load side lugs (neutral, leg 1, leg 2) to 2-wire lugs, I could wire in another EATON CHSPT2ULTRA to the load side of the disconnect switch. In the Eaton instructions for the SPD, they do not specify a maximum breaker size, since the leads to the SPD do not carry any supply currents. This might be a solution but I can't find any NEC reference to NEMA guidelines on wiring a SPD to a fusible disconnect.

 

[paulengr]

You get an additional 20 V per inch the further you get. Does it meet the BIL of the AFCIs?


Sent from my iPhone using Tapatalk

 

[synchro]

In between the generator and the transfer switch is a Siemens 100amp fusible disconnect switch. If I switched the single-wire load side lugs (neutral, leg 1, leg 2) to 2-wire lugs, I could wire in another EATON CHSPT2ULTRA to the load side of the disconnect switch. In the Eaton instructions for the SPD, they do not specify a maximum breaker size, since the leads to the SPD do not carry any supply currents. This might be a solution but I can't find any NEC reference to NEMA guidelines on wiring a SPD to a fusible disconnect.

The Eaton installation guide at the link below says:
"A dedicated 2-pole 15 ampere circuit breaker is recommended for use with CHSP devices, but use a 2-pole 50 ampere circuit breaker to achieve the full published ratings of the CHSPT2ULTRA device."

https://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestReleased&noSaveAs=0&Rendition=Primary&dDocName=IB00414001Y

One option would be to put a small MLO panel with feed-thru lugs and a 2-pole 50A breaker after the 100A fusible disconnect for the generator.

I think having one SPD in the 200-amp meter/load panel and another SPD for the generator's feeder is a good idea. It frees up a couple of spaces in the 200A main lug breaker panel which sounds like it's out of room. Also, having an SPD at the outside meter/load panel should protect the electronics within the ATS from POCO surges. These two locations for SPD's also might have less vulnerability than the inside panel to collateral damage if the SPD blows catastrophically which they have been known to do.

 

[Dennis Alwon]

I cannot find anything in the 2020 NEC that details SPD protection when a Type 2 SPD is on the load side of the meter/load panel and a transfer switch is between the meter/load center and the main inside panel. The SPD should be on the load side of both sources of power but I don't have that solution. Does anyone have a suggestion on how to provide surge protection when the generator is powered on and supplying power to the inside panel? Does it require an adjacent subpanel, powered by the main, inside, CB panel, with breakers for the Type 2 SPD and the two 15-amp circuits?

One more question, please: If the Type 2 SPD is connected to an outside panel, does it need GFCI protection?

Just so you know-- NC has an amendment that I believe will pass and it deletes the requirement of a SPD. This will become active probably on Oct,1 2021. It is just a proposal now but I believe it will pass.

https://www.ncosfm.gov/media/2068/open

 

[Bluetec]

Dennis, thank you for the insight on the deletion of required SPD devices. I understand the rationale for changes to the NEC, based upon catastrophic events involving humans, but have equated them to: "if a single rodent suffers a catastrophic incident, due to our lack of oversight, we have failed our mission to protect electrical circuits from such events". Yesterday, I removed the service panel from an outdoor A/C condenser unit and found a dead mouse that had been "fried" from simultaneous contact with the output terminals of a motor capacitor. If we had insisted that the terminals be insulated and isolated, to prevent such simultaneous contact, we could have saved this poor rodent's life. If you want to spend $30,000 for an 88-inch OLED television and have a Siemens whole-house surge protection device and your television "blows up" from a catastrophic surge that the SPD fails to protect; sorry, it is a plug-in device and is not covered under warranty.

 

[Dennis Alwon]

Dennis, thank you for the insight on the deletion of required SPD devices. I understand the rationale for changes to the NEC, based upon catastrophic events involving humans, but have equated them to: "if a single rodent suffers a catastrophic incident, due to our lack of oversight, we have failed our mission to protect electrical circuits from such events". Yesterday, I removed the service panel from an outdoor A/C condenser unit and found a dead mouse that had been "fried" from simultaneous contact with the output terminals of a motor capacitor. If we had insisted that the terminals be insulated and isolated, to prevent such simultaneous contact, we could have saved this poor rodent's life. If you want to spend $30,000 for an 88-inch OLED television and have a Siemens whole-house surge protection device and your television "blows up" from a catastrophic surge that the SPD fails to protect; sorry, it is a plug-in device and is not covered under warranty.

I was not making a judgement call but letting you know it was there. I also don't think a surge suppressor would have saved the rodents life...LOL

 

[Bluetec]

Dennis, my analogy was not directed toward you. In my short period of time participating in this forum it's been quite evident that you are one of the most knowledgeable and informed members and I highly value your input.

In regard to my dilemma with moving the Type 2 SPD, I still don't know how to solve the problem with the generator being active and the SPD being isolated. I could follow the NEMA advice of wiring another Type 2 SPD into the fusible disconnect.

I went back to the NEMA site and tried cross-referencing "SPD" and "Code" or "SPD" and "NEC" and the search yields a very brief narrative but when you go to the referenced link you get "Page Not Found". It seems, from their site, NEMA is distancing itself from the NEC, regarding SPDs, but, as manufacturers, they are still praising the benefits of an SPD protecting valuable components such as televisions and computers. When you go to each manufacturer's site and read the warranties associated with installing their SPD devices, those items are excluded.

I can imagine the reaction from a home or business owner, when a power surge or electrical spike occurs, their television or computer system, along with the SPD, is "fried", and they're told those items, which the SPD is designed to protect, are not covered under warranty and they're going to have to pay to replace the SPD.

 

[Dennis Alwon]

I can imagine the reaction from a home or business owner, when a power surge or electrical spike occurs, their television or computer system, along with the SPD, is "fried", and they're told those items, which the SPD is designed to protect, are not covered under warranty and they're going to have to pay to replace the SPD.

I get it.. BTW, no apology necessary

NC , IMO, is making a mistake by not requiring a concrete encased electrode. We use them wherever possible and they are great for dealing with surges. Of course, with a direct lightning strike nothing is going to protect the equipment.