SPD Direct Bus Installation

[Doc13067]

Mounting SPD's directly to busbars is very common. Siemens has a whole line of them that bolt on and mount to the feed thru lugs. I think you are being overly dramatic about this.

There we go, electrofelon, a name im familiar with (no offense to anyone else). My only question with this was about making some sort of splice in those wires after they leave the posts under the main breaker. If I were to install some sort of insulated detachable butt splice so if this thing takes a hit it can be very quickly replaced without killing the whole service is there any reason this would be prohibited? I sincerely appreciate everyone else trying to help.

 

[jim dungar]

There we go, electrofelon, a name im familiar with (no offense to anyone else). My only question with this was about making some sort of splice in those wires after they leave the posts under the main breaker. If I were to install some sort of insulated detachable butt splice so if this thing takes a hit it can be very quickly replaced without killing the whole service is there any reason this would be prohibited? I sincerely appreciate everyone else trying to help.

I believe a splice/disconnect, like you describe, could impact the performance of the SPD, which usually want shortest possible leads with as little bending as possible (90°bends are a definite non-no).

 

[jap]

I agree.

I would think an insulated detachable butt splice would become nothing more than a glorified fusible link and possibly remove the SPD from doing what is was installed to do in the first place.

JAP>

 

[electrofelon]

There we go, electrofelon, a name im familiar with (no offense to anyone else). My only question with this was about making some sort of splice in those wires after they leave the posts under the main breaker. If I were to install some sort of insulated detachable butt splice so if this thing takes a hit it can be very quickly replaced without killing the whole service is there any reason this would be prohibited? I sincerely appreciate everyone else trying to help.

Once I needed to put some ring terminals in a meter socket for an energy monitor. I wasn't thrilled about sandwiching a ring terminal between the lug and the nut, so I added another nut on top of the nut holding the lug on. Maybe something like that would work?

 

[jap]

He seems to be asking more about being able to disconnect the SPD for serviceability rather than how to connect it to the buss.

JAP>

 

[NTesla76]

Yes, do not attach directly to the bus bar(s) or either one of them.

You must understand that I do not have all the facts or have not seen your panel board.
You need to call an apropreately licensed electrician to do this. Not an apprentice licensed one.
Call a qualified licensed electrician.
So, with that in mind, what's approximate age of your house or have you ever replaced you panel board?
Here's what a licensed electrician will look for:
Load centers(panel board) all have a maximum number of circuit breakers that may be installed.
He may be able to look at the panel boards diagram and other important info on that label.

Count the number of circuit breakers and compare that number with what's on the information on the inside label of your panel board.
Some circuit breakers are what we call single pole CB's or two pole CB's So each one counts toward the maximum allowed.

So, if there's one or two single pole CBs you may be able to remove them to make room for the SPD.
You may have to do this for 2-3 other CBs to make room for the SPD breaker.
Some CBs are made to have two terminals for two circuits stabbed into one bus bar (1 phase of the 2 phases).
You may have some options to consider before you do anything.
Let your electrician read this, he will understand.

Do not connect directly into the energized bus bars as you have mentioned.
Again, consider an outside disconnect that will refeed your inside panel and put the SPD there in the new disconnect per Code.
Call a qualified licensed electrician.

TX+MASTER+#4544

 

[Doc13067]

Once I needed to put some ring terminals in a meter socket for an energy monitor. I wasn't thrilled about sandwiching a ring terminal between the lug and the nut, so I added another nut on top of the nut holding the lug on. Maybe something like that would work?

Yeah something like this could work if the posts in the home line panel are long enough. It’s a great idea. We could actually put a second set of nuts on the post and then we would only have to disconnect one of them to remove the SPD and we would not have to turn off the main breaker to do this because it would be tight to the bus bar at all times. I was thinking of using a butt splice style lever nut on each conductor or something like that.

 

[Doc13067]

He seems to be asking more about being able to disconnect the SPD for serviceability rather than how to connect it to the buss.

JAP>

Yes that is correct. I know how to install it and I know what the manufacturer says. I was just asking for some outside the box thinking based on the downside of doing it this way.

 

[Doc13067]

I believe a splice/disconnect, like you describe, could impact the performance of the SPD, which usually want shortest possible leads with as little bending as possible (90°bends are a definite non-no).

OK, thank you that is one of the things I was wondering if I might hear from you guys. If it would jeopardize the function of the SPD then I would just stop being creative and make sure everyone knows anytime we service it. The power gets shut off.

 

[jap]

Yeah something like this could work if the posts in the home line panel are long enough. It’s a great idea. We could actually put a second set of nuts on the post and then we would only have to disconnect one of them to remove the SPD and we would not have to turn off the main breaker to do this because it would be tight to the bus bar at all times. I was thinking of using a butt splice style lever nut on each conductor or something like that.

If Your panel takes a hit but doesn't destroy the SPD you're never going to know it unless you have the type that incorporates a surge counter.

If your panel takes a hit and destroys the SPD you're going to have to shut the main off to replace it anyway.

There should never be a reason you would ever have to change out a surge protection device Hot.

JAP>

 

[Doc13067]

If Your panel takes a hit but doesn't destroy the SPD you're never going to know it unless you have the type that incorporates a surge counter.

If your panel takes a hit and destroys the SPD you're going to have to shut the main off to replace it anyway.

There should never be a reason you would ever have to change out a surge protection device Hot.

JAP>

Right, it would just be a matter of which method I would use to deenergize the SPD, the main circuit breaker or whatever clever means I was able to implement after consulting this thread.

 

[Doc13067]

In the beginning nobody was understanding me

 

[TX+ MASTER#4544]

I believe a splice/disconnect, like you describe, could impact the performance of the SPD, which usually want shortest possible leads with as little bending as possible (90°bends are a definite non-no).

2023 NEC
Regarding..........." if your panel takes a hit and destroys the SPD........'

That shouldn't happen if the SPD is rated for the fault current available as per 242.8 Short Circuit Current Rating. "The SPD shall be marked with a short-circuit current rating and shall not be installed at a point on the system where the available fault current is in excess of that rating."

Does anyone or the installer know what the fault current was? I really doubt it.

NEC Commentary found in Article 100 indicates for a typical one family dwelling example with a 100 amp service supplied by a 37.5 kilovolt ampere transformer......at a distance of 25 feet, ........the available short circuit would be approximately 6,000 amperes.

A type one SPD is usually found at the service,242.13 (A) (B).

The commentary example is perhaps somewhat extreme inasmuch as the distance was only 25 feet and considering other given parameters.
Of course it is a fact that the closer / further distance is what will determine the impact on the amount of short circuit current available.

Please read on: It's worth your time.

Some say I am too involved in the Code to know what really goes on in the real world. I have a lot to say about that, so take the time to read the facts from the 2012 Edition NFPA 70E Standard for Electrical Safety in the Workplace.

Well, I have heard from a few licensed electricians who say that they should have been more involved considering how destructive it can be when short circuit currents explode in or near your body, especially your eyes while working on any energized equipment.

Here's a few real time facts about about what actually happens while working on energized equipment and suddenly you fumble your screw driver or other tool and create a phase to ground or phase -to- phase short. Some have been edited.

From the 2012 Edition of NFPA 70 E Informative Annex K General Categories of Electrical Hazards

K.2 Electric Shock. The current required to light a 7.5 watt, 129 volt lamp, if passed across the chest, is enough to cause a fatality. Affecting especially the lungs, heart, and brain. And that may be depending on how healthy you are.

K.3 Arc Flash. When an electric current passes through air between ungrounded conductors or between ungrounded and grounded conductors, the temperature can reach35,000 degrees Fahrenheit. Scientist say that's about 7 times hotter than the surface of the sun. Arc flashes can and do kill at distances of 10 feet. You can't outrun it.

K.4 Arc Blast. ."....can melt coper conductors, when it turns from a solid to a vapor. Knock workers off of ladders, rupturing ear-drums and collapsing your lungs. Molten metal is expelled away from the arc at speeds exceeding700 MPH fast enough for shrapnel to completely penetrate the human body."

Thanks for reading
Comments accepted
TX+MASTER#4544

 

[Doc13067]

Is this artificial intelligence or something?

 

[jim dungar]

Is this artificial intelligence or something?

I don't know. The most recent reply certainly had nothing to do with the quote it referenced. But it is not the first time one of our threads has been detoured.

 

[Knightryder12]

2023 NEC
Regarding..........." if your panel takes a hit and destroys the SPD........'

That shouldn't happen if the SPD is rated for the fault current available as per 242.8 Short Circuit Current Rating. "The SPD shall be marked with a short-circuit current rating and shall not be installed at a point on the system where the available fault current is in excess of that rating."

Does anyone or the installer know what the fault current was? I really doubt it.

NEC Commentary found in Article 100 indicates for a typical one family dwelling example with a 100 amp service supplied by a 37.5 kilovolt ampere transformer......at a distance of 25 feet, ........the available short circuit would be approximately 6,000 amperes.

A type one SPD is usually found at the service,242.13 (A) (B).

The commentary example is perhaps somewhat extreme inasmuch as the distance was only 25 feet and considering other given parameters.
Of course it is a fact that the closer / further distance is what will determine the impact on the amount of short circuit current available.

Please read on: It's worth your time.

Some say I am too involved in the Code to know what really goes on in the real world. I have a lot to say about that, so take the time to read the facts from the 2012 Edition NFPA 70E Standard for Electrical Safety in the Workplace.

Well, I have heard from a few licensed electricians who say that they should have been more involved considering how destructive it can be when short circuit currents explode in or near your body, especially your eyes while working on any energized equipment.

Here's a few real time facts about about what actually happens while working on energized equipment and suddenly you fumble your screw driver or other tool and create a phase to ground or phase -to- phase short. Some have been edited.

From the 2012 Edition of NFPA 70 E Informative Annex K General Categories of Electrical Hazards

K.2 Electric Shock. The current required to light a 7.5 watt, 129 volt lamp, if passed across the chest, is enough to cause a fatality. Affecting especially the lungs, heart, and brain. And that may be depending on how healthy you are.

K.3 Arc Flash. When an electric current passes through air between ungrounded conductors or between ungrounded and grounded conductors, the temperature can reach35,000 degrees Fahrenheit. Scientist say that's about 7 times hotter than the surface of the sun. Arc flashes can and do kill at distances of 10 feet. You can't outrun it.

K.4 Arc Blast. ."....can melt coper conductors, when it turns from a solid to a vapor. Knock workers off of ladders, rupturing ear-drums and collapsing your lungs. Molten metal is expelled away from the arc at speeds exceeding700 MPH fast enough for shrapnel to completely penetrate the human body."

Thanks for reading
Comments accepted
TX+MASTER#4544

If it takes a lightning hit that SPD is toast. SPD's are mainly for utility surges.

 

[TX+ MASTER#4544]

2023 NEC, Part III Surge Arresters, Over 1,000 volts, 242.40.These are installed where the voltage is at or greater than 1,000 volts. So basically voltage levels separate the two devices. Appears there are no specific surge arresters compared to SPDs as in found in Part II Section 242.14.
But serves the same function (connected to an ungrounded conductor).

However, SPD's have a tier rating such as a type 1 SPD. A type 1 SPD is installed at where the greatest potential would be found which is at the service (242.13(B) At the Service. (1)-(2) -(3) (4) and are connected to a grounded (neutral), service conductor, or grounding electrode conductor, or an EGC.

Did you notice that a type 1 SPD was connected to a grounding conductor? Makes sense to me that a ground connection will shunt the fault to ground. Maybe not all of it but enough to, perhaps, save your sensitive electronic equipment.

A Type 2 SPD (242.14 (A) will cause fault flow current to 'trickle' down stream to a feeder or protects a remote structure or to a dry type transformer.

Type 3 SPD on the load side of branch circuits and installed as per instructions at 30 feet of conductor distance from the service or separately derived system disconnect.

A type 4 SPD (242.18) is installed at the equipment manufactures plant.
An SPD is available as an integral part of a duplex receptacle and used as a point of use protection.

A personal note: I have a portable relocatable multiple strip(receptacles) with my computer, printer and the inter-net box plugged in to it with an integral SPD in the male end and plugged into an existing duplex wall outlet that tripped when we had a nearby lighting strike.

It saved every thing that was plugged into it!
Had I not had the SPD it would have been an expensive loss!
SPDs work. Thanks to the NEC.

Thanks for reading
Comments accepted
TX+MASTER #4544