# 400 Amp service



## david wise (Feb 17, 2010)

Okay I need to ask, I have a 400 amp service to do and I need help. I plan to bring my feed into a CT cabinet were I will feed my ungrounded conductors thru the CT's and into a 5ft. trough where I will bug them and feed to 2-200 amp panels. The building has no steel frame, no gas and is fed with PVC for water. My question is when I bring my grounded conductor into the trough should I bond it to a ground rod right there or should I feed it to both panels then bond or bond only at one panel. Also I'm not happy with the ground rod being the only form of grounding, all comments are appreciated. Thank you, Dave


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## Jeff000 (Jun 18, 2008)

Bond at first place of disconnect in the CEC. 

Run two ground rods if you are not happy with one.


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## RIVETER (Sep 26, 2009)

The code does not say you cannot have more than just a ground rod. Add more electrodes.


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## raider1 (Jan 22, 2007)

david wise said:


> Okay I need to ask, I have a 400 amp service to do and I need help. I plan to bring my feed into a CT cabinet were I will feed my ungrounded conductors thru the CT's and into a 5ft. trough where I will bug them and feed to 2-200 amp panels. The building has no steel frame, no gas and is fed with PVC for water. My question is when I bring my grounded conductor into the trough should I bond it to a ground rod right there or should I feed it to both panels then bond or bond only at one panel. Also I'm not happy with the ground rod being the only form of grounding, all comments are appreciated. Thank you, Dave


I personally would connect my grounding electrode conductor to the grounded conductor at the wireway. 250.64(D)(3) (2008 NEC) would be the applicable code reference.

You could also make the connection at both panels but IMHO this is more work.

Check out 250.64(D) for other methods of connecting the GEC to the grounded conductor where there are more than 1 service disconnecting means.

Chris


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## Toronto Sparky (Apr 12, 2009)

Two ground rods ten feet apart at service entrance.
Plumbing in the building (if copper) has to be grounded too I believe.
Was told even if the piping is not copper the plumbing fixtures should be grounded if in close proximity to electrical ground.
I assume they worry about the water/plumbing fixtures being at differant potential to the building ground.


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## McClary’s Electrical (Feb 21, 2009)

out of curiosity, could I ask why you're not metering it?


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## Electric Al (Mar 13, 2010)

Surely if there is a C.T. cabinet and C.T.s, it must be metered. :blink:


And don't call me Shirley !!!!:laughing:


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## McClary’s Electrical (Feb 21, 2009)

Electric Al said:


> Surely if there is a C.T. cabinet and C.T.s, it must be metered. :blink:
> 
> 
> And don't call me Shirley !!!!:laughing:


 


you know what I mean!! withou the CT's duh!,,,,most POCO's will meter 400 and some will meter 600


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## Dennis Alwon (May 9, 2009)

mcclary's electrical said:


> you know what I mean!! withou the CT's duh!,,,,most POCO's will meter 400 and some will meter 600


Wow- I have never heard or seen any single or 3 phase 600 amp meters without a CT. Are you sure of this?

Remember that a 400 amp meter that is metered without CT's is only rated for 320 amps continuous load.

If there were a 600 amp unit it would only be rated 480 amps continuous.

My point being this may be the reason the OP is using CT's. Their Poco also may not allow it any other way.


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## frenchelectrican (Mar 15, 2007)

Dennis .,

My shop in Wisconsin I have 400 amp bolt on metering { 480Y277V } and my POCO in my area stated that anything under 600 AMP can be bolted on but once you get over 600 amp it must be C/T.

I have to dig up my photo somewhere I know I did took it about 15 years ago.

But in France anything over 160 amp must have C/T no matter if single or triphase.

Merci,Marc


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## MDShunk (Jan 7, 2007)

Dennis Alwon said:


> Remember that a 400 amp meter that is metered without CT's is only rated for 320 amps continuous load.


That's what I used to think too, but there are true class 400 meters that meter a true 400 amps across the line.


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## Dennis Alwon (May 9, 2009)

MDShunk said:


> That's what I used to think too, but there are true class 400 meters that meter a true 400 amps across the line.


I have never seen one and I don't believe our poco would allow that. I will check.


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## MDShunk (Jan 7, 2007)

Here's a few pics of a true class 400 meter, that uses no CT's.


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## kbsparky (Sep 20, 2007)

Dennis Alwon said:


> ....a 400 amp meter that is metered without CT's is only rated for 320 amps continuous load.....


That applies to plug-in meters. Bolt-on meters and socket assemblies are available that can handle a full 400 Amp continuous load.


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## Dennis Alwon (May 9, 2009)

As you can see I don't mess with commercial stuff. Never used a bolt in meter before and I would be happy if I never use one.


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## david wise (Feb 17, 2010)

The service will definately be metered but at 5 amp instead of 400. When we looked at the total cost of everything it was much cheaper to go with the CT cabinet and CT'S because I already won them from another job which had fallen thru. PECO will be inspecting the job so I want to make sure that my bonding is properly done. I think I'm going to mount a distribution block in the trough and run all my bare copper to it, 2 ground rods, 2 panels and all bonding.


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## Innovative (Jan 26, 2010)

We usually dont CT till we are over 400 amps...... sometimes we can run 600 amps without a CT, using a K-base meter socket.


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## sparks134 (Jan 30, 2009)

What is a CT ???


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## Dennis Alwon (May 9, 2009)

sparks134 said:


> What is a CT ???


Current transformer. This basically takes the load off the meter. The wires get looped thru these small doughnut shaped CT's and the meter is fed with something like #12 wire. 

Meters are not designed to read heavy amperage so the CT's come into play on the higher loads.

Here is an idea of what they look like


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## NolaTigaBait (Oct 19, 2008)

sparks134 said:


> What is a CT ???


I thought you were a commercial guy...


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## SPINA ELECTRIC (Dec 1, 2009)

Shoot they use ct's in big houses on the hill over here in North Jersey and the money areas because most of them are 400 amps sometimes 600 amps.


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## sparks134 (Jan 30, 2009)

NolaTigaBait said:


> I thought you were a commercial guy...


Current transformer!:whistling2::whistling2:


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