SE Cable in Remodel

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RAYMFL

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Seminole Co
Have an existing 2 story house where the entire 1st floor has been rewired including replacement of the 200A branch circuit panel. New kitchen, laundry, lighting & etc. The entire 1st floor is bare down to the stud walls and rafters. The house was built sometime in the 70's with SE cable feeding the panel from the service. I have required the SE cable be replaced with SER cable to the branch circuit panel and the owner doesn't want to incur the expense of replacing the cable. Would like some objective opinions on this situation.

Ray
 
It was a violation then, it is a violation now. In my opinion you can require it to be fixed.

But how about we work this from another direction?

I don't think you could sign off on any of the new circuits run from this panel as they will all be in violation of 250.24(A)(5) or 250.142(B).

So they can keep the panel, they can keep the SE, but none of the new circuits can originate in that panel. :D
 
It is in violation, not much an electrical contractor can do except explain the violation and advise them what action the the inspector might take. .

In Massachusetts we have rule # 3 which states;
Rule 3. Additions or modifications to an existing installation shall be made in accordance with this Code without bringing the remaining part of the installation into compliance with the requirements of this Code. The installation shall not create a violation of this Code, nor shall it increase the magnitude of an existing violation.

Key words are "nor shall it increase the magnitude of an existing violation " .The Question then becomes would adding a circuit to this sub panel increase the magintude?? I would say it does.
 
RAYMFL said:
Have an existing 2 story house where the entire 1st floor has been rewired including replacement of the 200A branch circuit panel. New kitchen, laundry, lighting & etc. The entire 1st floor is bare down to the stud walls and rafters. The house was built sometime in the 70's with SE cable feeding the panel from the service. I have required the SE cable be replaced with SER cable to the branch circuit panel and the owner doesn't want to incur the expense of replacing the cable. Would like some objective opinions on this situation.

Ray
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If I was inspection this job the owner would have to incur the expense. There is enough work bring done to concider this new construction. Panel replacement and all walls and ceilings open is the trigger and makes it very easy. Panel replacement is no different then panel relocation which would require wire replacement.
 
iwire said:
It was a violation then, it is a violation now. In my opinion you can require it to be fixed.

But how about we work this from another direction?

I don't think you could sign off on any of the new circuits run from this panel as they will all be in violation of 250.24(A)(5) or 250.142(B).

So they can keep the panel, they can keep the SE, but none of the new circuits can originate in that panel. :D
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I don't know if it was a violation when built since we were governed by local codes at the time and remember that was and acceptable practice and don't remember when the change was made. I agree with the reverse direction and had thought that was an approach but had not considered all the circuits (120V), but its true, they would all have to origonate from the service disconnect panel or a panel that conformed to 250.24(A)(5). I will likely have to state my case on Monday as the owner has taken this matter to a higher level and I need to be able to support my reason.
Ray
 
Cavie said:
If I was inspection this job the owner would have to incur the expense. There is enough work bring done to concider this new construction. Panel replacement and all walls and ceilings open is the trigger and makes it very easy. Panel replacement is no different then panel relocation which would require wire replacement.
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We have checked the value of the remodel and it does not appear meet the 50% rule which is the how the statute determines enough work to consider it new construction.

Ray
 
The electrical contractor is not objecting to this...only the owner. Apparently the contractor informed the owner this may be required and quoted a price to upgrade the panel feeder. It has been left for the inspector to enforce. If I'm not mistaken, the origonal quote was for running the new cable up to the 2nd floor, across the attic and back down to the service. Now with the entire 1st floor exposed, it would be about 40' +/- pretty much a straight shot to the service panel that is on the outside of an exposed wall. I think he (the owner) should get a new estimate because it may not be as costly.
 
I would be surprised if it were in compliance ,... even way back in the 70s local rules and all. You should be on solid ground here ,...:smile: pun intended. He will spend more running the circuits back to the service equipment,,most likely .
 
It's possible the house is older than I said. The panel that was changed is an old FPE and they have been used in this area since the late 50's, I believe, and the house isn't that old . Out of curiousity, I could check the records to se when it was built. Anyway, I need to stay focused on the current issue at hand and persue compliance with the current code.
 
This guy has been on this issue for quite some time ,.. thought you might want to read it . Good luck.

NEC Rules on Neutral-to-Ground Connections
By Mike Holt, Published in Power Quality Magazine

Section 250-142 - To protect against dangerous touch voltage, an effective ground-fault current path (EGFP) must be provided and it becomes complete when it is bonded to the power supply system grounded (neutral) conductor. This neutral-to-ground connection (as it?s called) is to be made at either the service equipment enclosure or at the source of the separately derived system.

Service Equipment - At service equipment (the building disconnecting means), the EGFP is established by bonding the metal service disconnect enclosure to the service grounded (neutral) conductor [250-24(b)]. This neutral-to-ground connection is accomplished by the installation of a main bonding jumper (screw or strap) in accordance with Section 250-28.

Author?s Comment: The main bonding jumper is required to be supplied by the disconnect equipment manufacturer [384-3(c)].

Separately Derived Systems - For separately derived systems, the EGFP is established by when the metal enclosure of the separately derived system (transformer, generator, UPS system, or photovoltaic system) is bonded to grounded (neutral) terminal (X0) of the power supply in accordance with Section 250-30(a)(1). This neutral-to-ground connection must be made at either the separately derived system or at the first system disconnect after the separately derived system.

DANGER: Failure to provide an EGFP for services and/or separately derived systems can create any one or more of the following:
? Dangerous touch voltage will remain on all metal part of the electrical system whenever a line-to-case fault occurs.
? Metal parts of the electrical system can have dangerous touch voltage from the normal operation of the electrical system.
? Neutral current attempting to return to the power supply can cause wood members of the building to ignite from ?pyroforic-carbonization?.

Author?s Comment: A video demonstrating ?pyroforic-carbonization? is available from my office, 1-888 NEC Code. Ask for the open-neutral video.

The NEC permits a neutral-to-ground connection at separate building and structures disconnecting means, when installed in accordance with Section 250-32(b)(2). However, this is a very dangerous practice and should be avoided.

NEC Section 250-142(b) contains two exceptions where a neutral-to-ground connection is permitted on the load side of the service or separately derived systems. Exception No.1 permits a neutral-to-ground connection for existing ranges, dryers, and ovens as are limited in Section 250-140. Exception No. 2 allows a neutral-to-ground connection at meter enclosures on the load side of the service disconnect, if the meter enclosures are located near the service disconnect and no ground-fault protection is installed at the service.


The Danger of Improper Neutral-to-Ground Connections

The purpose of the NEC ?is the practical safeguarding of persons and property from hazards arising from the use of electricity? [90-1(a)]. A neutral-to-ground connection must not be made on the load side of service equipment of separately derived systems except as permitted in Section 250-142(b). The reason neutral-to-ground connections are only permitted at service equipment and separately derived systems is so that dangerous (neutral) current will not flow on the metal parts of the electrical systems in violation of Sections 250-6 and 250-142(b).

Neutral-to-ground connection can be cause by wiring errors such as neutral-to-ground shorts in receptacles, shorted surge suppressor, ballast wires caught under ballasts or ballast covers, etc. But most commonly, improper neutral-to-ground connections are made when the neutral conductor is bonded to the metal case of a subpanel.

Author?s Comment: An improper neutral-to-ground connection can create a condition where neutral current has multiple parallel paths to return to the power supply. This condition (parallel neutral paths) creates ?ground loops?, ?net currents? and the condition of ?objections current? on the EGFP, a violation of Section 250-6.

Objectionable (neutral) current flowing on the metal parts of the electrical system can cause fires, electrocution, and power quality issues with sensitive electronic equipment.

Electrocution. Death from electric shock (electrocution) can occur when as little as 50 mA of current flows through the human body. This current flow disrupts the hearts electrical circuitry causing it to go in to ventricular fibrillation. Ventricular fibrillation (VF) is a condition where the heart no longer pumps blood through the body, particularly the brain. VF can occur when the touch voltage is greater that 30V, resulting in a current flow of more than 50 mA through the body. This can occur when the effective ground-fault path (EGFP) becomes the primary path for neutral current, and a person gets in series with this path.

Example: A 120V water filter is installed at a location where a grounded (neutral) conductor is not available (only 240V for the motor) and the installer used the EGFP for the neutral conductor. Under this condition, if a person got in series with the EGFP, they could get killed.

Fire Hazard. Fire is created when heat rises to a level that is sufficient to cause ignition of adjacent combustible material in an area that is oxygenated. In an electrical system, heat is generated whenever current flows through an object in accordance with the formula I2R. Where ?I? is the magnitude in amperes of the current and ?R? is the resistance in ohms of the object.

Improper wiring resulting in a condition where neutral current flows through the EGFP can cause the temperature at loose connections to rise to a level that can cause a fire. In addition, arcing at loose connections because of neutral current flowing through the EGFP is particularly dangerous in areas containing easily ignitable and explosive gases, vapors, or dust.

Power Quality Problems from Improper Neutral-to-Ground Connections

Elevated Ground-to-Earth Voltage. When a neutral-to-ground connection is made at more than one location (ground loop), objectionable neutral current will return to the source through much of the electrical system and building. The result will be a rise in the voltage difference between the metal parts of the electrical system and the earth.

Electromagnetic Interference (EMI). In addition to the health issue as to the effect of electromagnetic fields on the human body, EMI from ?net current? (objectionable current on the EGFP and building structure) can disrupt the performance of sensitive electronic equipment and devices, particularly video monitors, electronic microscopes, etc.

Author?s Comment: For more information about Power Quality as it related to grounding, visit www.mikeholt.com/Powerquality/Powerquality.htm
__________________
God Bless, Mike Holt
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It is routed from the family room (formerly garage) to the second floor, through the attic and down to the service. Now there is a pretty much straight shot to the back of the service disconnect without leaving the 1st floor. The owner was informed today that he will have to comply and run a new service cable.
 
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