Home>Discussions>TV>TV House Projects>Newton Centre (2009)>Whoa, major electrical safety violations
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Edge1289
Re: Whoa, major electrical safety violations
NEC wrote:

I hugely disagree. I have done many a service change and have shunted the meter out. Three phase meters even have a handle and shunts built in. As long as I called the power company telling them I had a closed loop I have not had a problem in 30+ years.

The utility I work for doesnt allow an electrician to bypass the meter. You call the power company, a crew shows up does the disconnect, you do your work, the crew returns heats it back up. Residential, $212 ripoff that the regulators allowed. Commercial 3 phase, depends.......

Timothy Miller
Re: Whoa, major electrical safety violations

Howdy i cringed when the Electrician grabbed the live wires and strapping cable with a bare hand. Kids watch this show so shame on TOH...... Safety glasses are always referred to but is that the extend of their idea of safety... Boneheads! This needs to be addressed on a future program to warn kids to never touch these lines- including tall middle aged kids. Sudden death not addressed is sure more nasty then putting an eye out. otherwise. Shame Shame Shame.

Lineman's gloves and caution to never grab these energized lines would of been the professional first heads up!
Has that electrician never seen a short caused by worn insulation on wire? Man turn the channel....

Ernie_Fergler
Re: Whoa, major electrical safety violations
NEC wrote:

How is power cut to a single residential service?

Edge1289's post describes the process to a "T".:D

rtparso
Re: Whoa, major electrical safety violations
NEC wrote:

How is power cut to a single residential service?

Every place I have seen, for above ground service there is a fused switch on the pole. Takes about 30 seconds. VS if 2 of the wires had touched you would of had an arc flash that would have at least knocked both of them off the ladders. Melted all the exposed synthetic cloth. At least second degree burns most likely some time off work with burned hands.

JLMCDANIEL
Re: Whoa, major electrical safety violations

The fused switch controls power to the transformer, in some places one transformer feeds multiple homes.
Jack

canuk
Re: Whoa, major electrical safety violations
rtparso wrote:

Every place I have seen, for above ground service there is a fused switch on the pole. Takes about 30 seconds. VS if 2 of the wires had touched you would of had an arc flash that would have at least knocked both of them off the ladders. Melted all the exposed synthetic cloth. At least second degree burns most likely some time off work with burned hands.

The switch for our utility feed is further upstream ( down the lane ) ---- so without knocking power out for about a dozen homes ---- how else would you do it ?

Edge1289
Re: Whoa, major electrical safety violations
canuk wrote:

The switch for our utility feed is further upstream ( down the lane ) ---- so without knocking power out for about a dozen homes ---- how else would you do it ?

See my first post on this page.....

Edge1289
Re: Whoa, major electrical safety violations
rtparso wrote:

Every place I have seen, for above ground service there is a fused switch on the pole. Takes about 30 seconds. VS if 2 of the wires had touched you would of had an arc flash that would have at least knocked both of them off the ladders. Melted all the exposed synthetic cloth. At least second degree burns most likely some time off work with burned hands.

The fused switch is known as a cut-out box, it generally fuses transformers or primary branch circuits. Cut-boxes are not used to disconnect individual service connections.

NEC
Re: Whoa, major electrical safety violations
Edge1289 wrote:

The fused switch is known as a cut-out box, it generally fuses transformers or primary branch circuits. Cut-boxes are not used to disconnect individual service connections.

Ummm, yes I have a masters license. I was curious to how power was cut on a single residence when a transformer tap might feed multiple homes in different areas of the country and with different power suppliers regulations...... It goes beyond the NEC and is not really covered in NFPA-70E.

I would say that a lateral cut to the home is no more safe either by an electrical contractor or the "Power Company" as long as I follow 70E.

I would also say that fault current at a residence is seldom more than 10k and arc flash is minimal.

Edge1289
Re: Whoa, major electrical safety violations
NEC wrote:

Ummm, yes I have a masters license. I was curious to how power was cut on a single residence when a transformer tap might feed multiple homes in different areas of the country and with different power suppliers regulations...... It goes beyond the NEC and is not really covered in NFPA-70E.

I would say that a lateral cut to the home is no more safe either by an electrical contractor or the "Power Company" as long as I follow 70E.

I would also say that fault current at a residence is seldom more than 10k and arc flash is minimal.

I have worked on a few different utility properties during my 37 year career during "storm trouble." Every property Ive worked on had similar means to diconnect individual overhead services. You cut the individual service at the point of attachment on the pole or the house. If the service is a midspan tap, that is to say the deadend connection is between poles, the disconnect is still done in the same manner. As I said, UG residential distribution has come a long way in my career. Disconnects are done either in a transformer or a secondary enclosure. Subway, or what i call conventional UG that feeds from manholes is disconnected in the manhole that the service originates from.

I will preface my next statement with the disclaimer;) that I am not an engineer. But here goes, available fault current is partially determined by the total KVA of the transformers feeding the services. Obviously distance from the source and conductor size come into play. Lets say you are going to disconnect a single phase 120/208 service that feeds from a 3 phase overhead network. The network is fed by 5-3 phase banks of 225 KVA each and the banks are tied together at the secondaries with the standard malimiter fuses. Your service is 50 ft long and is # 2 stranded CU. What is the avaible fault current should a phase to phase flash occur.

If you look at NFPA 70e, within the first few pages, you will find that electric utilities are exempt so those regs. dont apply to me. OSHA 1910.269 apply and say I can wear 100% cotton. I am not required to wear FR by osha and I work on equipment with much higher available fault current that 120/240 house services. 70e is a little much, i would be wearing a full flash hood if 70e applied to me.

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