SPD Direct Bus Installation

[Doc13067]

I am looking to install Schneider surge protection device specifically the HEPD80. And I want to do the direct bus connection because the load center is loaded and I don’t want to rearrange breakers and reschedule the panel. Schneider pointed out that the only downside is if this thing ever needs to be replaced it’s a pain because you have to shut off the power and disconnect the nuts holding the main breaker to the bus. I’m sure that would not be the end of the world, but I was just curious if anyone has ever done this and installed some sort of quick detach connectors on the wires so that they could be disconnected from the bus and left hanging in the load center while you took out the SPD and replaced it with a new one. I was thinking of some sort of insulated connector that has pins on the inside, so no exposed metal would come in contact with the enclosure in the event of needing to disconnect for replacement. Do you guys have any thoughts on that?

 

[TX+ MASTER#4544]

Yes,Doc13067

Do not do this! It would be a violation of NEC and extremely dangerous to you or somebody else.

Listen to Schneider's advice.

Do you have an exterior disconnect ahead of your inside load center?
If not maybe you could install one and be in conformance with having an emergency disconnect for first responders.
If so, install it there and it will conform to NEC.

Also, the SPD shall have a rating at or above your short circuit rating at the service entrance terminals, that's per NEC code.
Contact the manufacturer of the load center or the supply house to get the SCCR, (short circuit current rating).
Do not gamble with this.

TX+MASTER#4544

 

[Doc13067]

When you say do not do this, which part are you referring to? The quick disconnect connectors?

 

[Doc13067]

Just to clarify, this is a type one SPD that is able to be connected in a direct bus manner. This is not something that I am making up. I just got off the phone with Schneider and they explained the downside is that if you have to change the SPD you have to power down, the main breaker (which is my main disconnect ahead of the SPD direct bus connection). I am simply asking if anyone has ever done this and create it using connectors some type of disconnecting method for the SPD to avoid having to turn off the main breaker in the event of needing to replace the device.

 

[jap]

Although you could, I think you'll find the suggested way to connect this SPD to the bus is via a 2p 30a Breaker.

Why complicate the issue?

There are way more cons than pros when attaching a SPD directly to the buss rather than using some means of disconnect ahead of it.

JMHO.

JAP>

 

[TX+ MASTER#4544]

When you say do not do this, which part are you referring to? The quick disconnect connectors?

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

 

[__dan]

I am looking to install Schneider surge protection device specifically the HEPD80. And I want to do the direct bus connection because the load center is loaded and I don’t want to rearrange breakers and reschedule the panel. Schneider pointed out that the only downside is if this thing ever needs to be replaced it’s a pain because you have to shut off the power and disconnect the nuts holding the main breaker to the bus. I’m sure that would not be the end of the world, but I was just curious if anyone has ever done this and installed some sort of quick detach connectors on the wires so that they could be disconnected from the bus and left hanging in the load center while you took out the SPD and replaced it with a new one. I was thinking of some sort of insulated connector that has pins on the inside, so no exposed metal would come in contact with the enclosure in the event of needing to disconnect for replacement. Do you guys have any thoughts on that?

Installations instructions say install downstream of a 30 Amp Breaker. There is no way around that. You could tap the bus and add the breaker externally but likely it's possible to rearrange existing circuits and double something else up for two spare poles.

Even adding the SPD to an existing 30 A 2 pole feeding something else paralleled on that breaker would imo, be OK. Straight on the bus with no 30 A OCPD, definitely no.

The SPD's usually have internal MOV's that short transients to ground, but they can routinely fail catastrophically for transients shorted above their rating. Usually they would have internal fuses also for that, but in your case you would be depending on the external enclosure to contain the MOV's failing, plus the 30 A OCPD to open when it needs to.

 

[Doc13067]

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 mentions

My friend, thank you for attempting to help. I am a licensed electrician as everyone on this site should be. Type 1 SPDs are designed to be installed on the line side of the service disconnect in my case this would be a main breaker. But that is not usually practical and the instructions for this particular unit do not show putting it on the line side. They instead show putting it on the load side but still directly connected to the bus via the posts that the main breaker connects to. My question was never whether or not it could be connected directly to the bus as it’s a fact that it can and I have attached the instruction manual for you guys to look at page 4 through 6 to see what I am talking about. My question was about installing connectors on the wires so they could be detached without having to shut the main breaker off. Is there anyone out there that knows what I am asking? Where is Larry Fine ️?

 

[Ken_S]

Installations instructions say install downstream of a 30 Amp Breaker. There is no way around that. You could tap the bus and add the breaker externally but likely it's possible to rearrange existing circuits and double something else up for two spare poles.

Even adding the SPD to an existing 30 A 2 pole feeding something else paralleled on that breaker would imo, be OK. Straight on the bus with no 30 A OCPD, definitely no.

The SPD's usually have internal MOV's that short transients to ground, but they can routinely fail catastrophically for transients shorted above their rating. Usually they would have internal fuses also for that, but in your case you would be depending on the external enclosure to contain the MOV's failing, plus the 30 A OCPD to open when it needs to.

View attachment 2570617

The installation instructions provide a procedure to connect directly to the buss after the main breaker. I think this is a terrible idea yet UL, and the NEC allow type 1 SPDs to connect to the service.

 

[Doc13067]

Although you could, I think you'll find the suggested way to connect this SPD to the bus is via a 2p 30a Breaker.

Why complicate the issue?

There are way more cons than pros when attaching a SPD directly to the buss rather than using some means of disconnect ahead of it.

JMHO.

JAP>

Thank you for understanding. I agree usually but in this case the direct bus would be more convenient. And if there are no listed quick connect devices that could be used then I would just resolve to knowing that the main breaker would have to be turned off anytime this unit needs to be replaced. That is really the only issue because the two nuts are very easy to unscrew and reinstall

 

[Doc13067]

The installation instructions provide a procedure to connect directly to the buss after the main breaker. I think this is a terrible idea yet UL, and the NEC allow type 1 SPDs to connect to the service.

You would probably never see them on the line side because most service equipment does not have the appropriate hardware for a second set of wires before the disconnect. At least after the disconnect it is still protected by the main breaker, although those little wires will not hold up well with 100 or 200 amps If it shorts out and the breaker trips

 

[jap]

I guess one could utilize the tap rule with a properly sized conductors with eyelets to a din rail mounted circuit breaker just for the SPD.

Wouldn't be my first choice by any means.

JAP>

 

[__dan]

Yes, I see the direct bus installation instructions. So the SPD manufacturer allows it.

The screw point they show, from memory I seem to recall they are sometimes a special nut, requiring special tool (not likely).

I took a quick look at a GE 200 A main breaker copper busbar. The bolts are regular hex head, but, it's obvious how it's built.

They take special care around the breakers and busbar with heavy high raised insulators and ridges. This is for arcing and flashover protection. Flashover deposits on insulators and makes them conductive, causing burndown. They took special care to mitigate this.

I would not think of terminating there, and I have tapped and drilled busbars for taps before. You would be routing your wires over their flashover protection, and imo, probably defeating what they put in to avoid that.

So you would be up against the panelboard manufacturer's instruction as well as the SPD maker's. Does GE allow you to tap the busbar at that point, can you find that allowance in their instructions. Probably no, and if not, not allowed.

Looking at the GE panel and asking myself if I would tap #14 wires to those bolts as the SPD shows, at the main beaker to busbar, it looked very adventurous. and I could see how it would be going around and through, exactly where they had heavy high raised insulating wraps specifically to control flashover.

Lot more work also compared to just doubling up on an existing dryer or A/C breaker.

No Thank You.

 

[__dan]

They show the direct bus connection in a picture where the pole spaces are there right next to it. Marketing guys.

The SPD is a sacrificial disposable part. It is made to do its job, take a hit, fail, and get throw away. Maybe smoking a little on the way. Don't forget, it is shorting the full hit when can be over rating and go poof. It is literally designed to go poof.

You want to be able to throw that part away without damage to the panel. It is supposed to sacrifice itself and save that. I am sure it has fusible links internal. It has to or it would keep burning.

Literally a photo of what not to do.

 

[electrofelon]

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

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.

 

[electrofelon]

https://www.siemens.com/download?BTLV_27123

Not to mention any of the BSPD breaker form factor SPD's for bolt on panelboards.....

 

[jap]

Looks like a Schneider SPD connected to a Sq. D Panel shown in a Schneider instruction manual.

If it takes a direct hit there will probably as big a "poof" whether its connected to the buss bar or a 2p 30a breaker.

JAP>

 

[TX+ MASTER#4544]

My friend, thank you for attempting to help. I am a licensed electrician as everyone on this site should be. Type 1 SPDs are designed to be installed on the line side of the service disconnect in my case this would be a main breaker. But that is not usually practical and the instructions for this particular unit do not show putting it on the line side. They instead show putting it on the load side but still directly connected to the bus via the posts that the main breaker connects to. My question was never whether or not it could be connected directly to the bus as it’s a fact that it can and I have attached the instruction manual for you guys to look at page 4 through 6 to see what I am talking about. My question was about installing connectors on the wires so they could be detached without having to shut the main breaker off. Is there anyone out there that knows what I am asking? Where is Larry Fine ️?

Hey,Doc13067, et al.

Now that I have seen the image of the installation I have a much better feeling about what was originally posted.
Actually you're not really drilling and tapping out a threaded hole for a threaded machine screw to make it adaptable directly to the bus bars.
That was my understanding when I read the original post. Hence my serious warning about drilling into the bus bars.

The mfg's installation instructions seems to make it clear to mount it as shown in the images.
I think the OP said the device(SPD) was loosely left dangling without support as required as shown in the installations.

That is a violation of the installation instructions as per mfg. The mfg shows it to be mounted via the threaded nipple with a lock-nut.

Can the panel cover be replaced without damage to the SPD?
Also, are the crimp-on terminals factory installed?
And, it looks like the SPD is on the load side of the 200 A CB so you can turn it off and safely replace the SPD if ever needed ?
If not, it too is a violation of NEC and NFPA 70E.

Now, I think we all can breath a sigh of relief knowing that he is not drilling into the energized bus bars.
Thanks to the OP for the installations image.

I don't know where Larry Fine is. He'll surface.

Forever posting
Always reading something electrical
Thanks,
TX+MASTER#4544

 

[roger]

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.

I have installed a number of those. In the 80's and 90's most of the ones I installed were directly connected.

 

[electrofelon]

Looks like a Schneider SPD connected to a Sq. D Panel shown in a Schneider instruction manual.

If it takes a direct hit there will probably as big a "poof" whether its connected to the buss bar or a 2p 30a breaker.

JAP>

Right, I know I was talking about a different manufacturer and a different product - my point was just that it is common to mount spd's directly to bus bars without any disconnect, over current protection, etc. It would be my preference to use a breaker, but often times panel spaces are precious.