Service Entrance Conductors Tap Rule - Electrician Talk - Professional Electrical Contractors Forum

aksparky · 09-17-2010, 10:08 AM

I have an install where I need to tap the SE conductors in the Load Center right before they land on the main breaker.
This is a residential install, I would use listed ilsco wire taps and then go directly into an inline fuse holder to protect the tap wires which will be #12 conductors that are sensing leads to a resi generator.

Ive looked at 240.21 and article 725 and also looked thru article 230 and cant seem to find anything prohibiting this, is this a legal install or am I grasping?

Thanks in advance

Toronto Sparky · 09-17-2010, 10:22 AM

I would say that local POCO may have something to say about that..

jwjrw · 09-17-2010, 11:33 AM

Quote:

Originally Posted by Toronto Sparky

I would say that local POCO may have something to say about that..

Why? He said main breaker which would be service entrance cables. Not poco's feeder. Or am I mis understand you?

jwjrw · 09-17-2010, 11:35 AM

Quote:

Originally Posted by aksparky

I have an install where I need to tap the SE conductors in the Load Center right before they land on the main breaker.
This is a residential install, I would use listed ilsco wire taps and then go directly into an inline fuse holder to protect the tap wires which will be #12 conductors that are sensing leads to a resi generator.

Ive looked at 240.21 and article 725 and also looked thru article 230 and cant seem to find anything prohibiting this, is this a legal install or am I grasping?

Thanks in advance

I'm not an expert on the tap rules but I'd say it is legal if you size the tap conductors properly.

Toronto Sparky · 09-17-2010, 12:11 PM

In my house the main disconnect is before the meter. (and has seal on it)

Not really related but here in Toronto (and I assume everywhere) the disconnects that feed elevators have a set of contacts (microswitch) that bypasses the return to lobby function when disconnect is shut off .. Do they make a main breaker with this contact?

Bob Badger · 09-17-2010, 12:27 PM

Quote:

Originally Posted by aksparky

Ive looked at 240.21 and article 725 and also looked thru article 230 and cant seem to find anything prohibiting this, is this a legal install or am I grasping?

Nothing in 240.21 applies to service conductors .

You may be able to make the tap, but all the conductors must be larger then the connected load.

However, these taps would have to go directly to a service rated and bonded disconnecting means, they cannot simply run to fuse holders.

jwjrw · 09-17-2010, 12:41 PM

Quote:

Originally Posted by Toronto Sparky

In my house the main disconnect is before the meter. (and has seal on it)

Not really related but here in Toronto (and I assume everywhere) the disconnects that feed elevators have a set of contacts (microswitch) that bypasses the return to lobby function when disconnect is shut off .. Do they make a main breaker with this contact?

Sad thing is I know you are in Canada but didn't think about your codes being different. I believe our ocpd can only be on the load side of poco.

InPhase277 · 09-17-2010, 03:29 PM

Quote:

Originally Posted by jwjrw

Sad thing is I know you are in Canada but didn't think about your codes being different. I believe our ocpd can only be on the load side of poco.

It is not so much of a code issue as it is a utility preference. Some POCOs want a switch before the meter to disconnect the socket during meter change outs and what not.

jwjrw · 09-17-2010, 03:32 PM

Quote:

Originally Posted by InPhase277

It is not so much of a code issue as it is a utility preference. Some POCOs want a switch before the meter to disconnect the socket during meter change outs and what not.

I actually meant the utility codes.

I've never seen a disconnect for a meter where I am.

Toronto Sparky · 09-17-2010, 03:35 PM

Quote:

Originally Posted by jwjrw

Sad thing is I know you are in Canada but didn't think about your codes being different. I believe our ocpd can only be on the load side of poco.

As I said My meter is after the disconnect, however the outside meters would be before the main disconnect..

My place has an indoor A-Base type meter the incoming feed goes to the line side of the disconnect then from load side to the meter , then to the main breaker on the panel.. (Originally the panel was a fuse panel with no main fuses in the panel as the disconnect handled fusing and disconnecting means.)
It also had a 30A plug fuse disconnect fed off the main disconnect load side that fed the flat rate water tank :-)
This house was built in the early 50s..

Bob Badger · 09-17-2010, 03:36 PM

Quote:

Originally Posted by jwjrw

I actually meant the utility codes.

I've never seen a disconnect for a meter where I am.

Here it is a very common power company requiment for 480 volt services.

It can be a service disconnect with over current protection or it can be a non fused disconnect that the NEC calls a 'meter disconnect' you would still have to install a service disconnect on the load side of the meter.

jwjrw · 09-17-2010, 03:39 PM

Quote:

Originally Posted by Bob Badger

Here it is a very common power company requiment for 480 volt services.

It can be a service disconnect with over current protection or it can be a non fused disconnect that the NEC calls a 'meter disconnect' you would still have to install a service disconnect on the load side of the meter.

Last 480v service I did was only 100a and they didn't require it here. Not saying other areas here don't require it. But in my short life I have not noticed one here. It's interesting to hear what some areas require and don't require.

Bob Badger · 09-17-2010, 03:43 PM

Quote:

Originally Posted by jwjrw

I have not noticed one here. It's interesting to hear what some areas require and don't require.

You likely will, it has to do with power company employee safety.

If you are plugging in a 7 jaw meter into a live 480 three phase socket it can cross, short and get real ugly fast.

jwjrw · 09-17-2010, 03:51 PM

Quote:

Originally Posted by Bob Badger

You likely will, it has to do with power company employee safety.

If you are plugging in a 7 jaw meter into a live 480 three phase socket it can cross, short and get real ugly fast.

I might even become 1/2 an union electrician one day if I study hard.

Thanks for the info Bob. I'm gonna start looking. I may of seen one without realizing it. But I know poco set a transformer on the pads we made and went to the meter on the last two we did. Is it possible they had a disconnect on their side in transformer box?