200A Panel w/a 150A Entrance Cable?

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Old 08-17-11, 05:49 AM
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200A Panel w/a 150A Entrance Cable?

Is it a problem to install a 200A Circuit Breaker panel w/an existing 150A entrance cable. Someone told me that would lead to an over-fused circuit, but thinking it through, the greater capacity "down stream" shouldn't be a problem if there is less current coming in.
 
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Old 08-17-11, 07:08 AM
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What do you mean by entrance cable? Do you mean SE. What size? Aluminum or copper wire. What is the amp rating of your meter and socket?

If even one of those is not rated 200 amps or greater a larger breaker can allow more current then they can handle.
 
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Old 08-17-11, 09:01 AM
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Thanks for the reply. To answer your question, I'm referring to the service main coming in from the street (150 Amp) to the main panel (200 Amp)
 
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Old 08-17-11, 09:04 AM
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The breaker needs to be sized for the cable. If your cable can only support 150 amps that is the size main you need.

You could install 200 amp cable on the 150a panel.
 
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Old 08-17-11, 09:27 AM
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If the 200A panel has a 150A main breaker it would be okay. It would not be okay with a 200A main breaker.
 
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Old 08-17-11, 03:57 PM
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It may be useful to note that the rules for the wires the utility company can use (for between the transformer on the pole and the top of your mast) are different than the rules for what size and kind of wire you need to use from that point on. Or, at least it was in my case in California.
 
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Old 08-17-11, 04:14 PM
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I had my service upgraded from 100 amps to 200 amps. The cable from the panel to the weather head was replaced. The POCO's cable from there to the pole is still the same. Turns out the POCO is cheap and will only replace it if it burns up and falls down.
 
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Old 08-17-11, 04:52 PM
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I had my service upgraded from 100 amps to 200 amps. The cable from the panel to the weather head was replaced. The POCO's cable from there to the pole is still the same. Turns out the POCO is cheap and will only replace it if it burns up and falls down.
My meter was moved about 15-16 years ago and updated from 60 to 200A. My drop is 2) 2AWG loosely wrapped around an aluminum guide wire which is the neutral. They will also only replae it if it melts.
 
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Old 08-17-11, 05:06 PM
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Originally Posted by drooplug View Post
I had my service upgraded from 100 amps to 200 amps. The cable from the panel to the weather head was replaced. The POCO's cable from there to the pole is still the same. Turns out the POCO is cheap and will only replace it if it burns up and falls down.
Typically, most power companies size the service drop according to the load at the house served. Just because you upgrade your service, why should the power company increase the size of the drop if there is no additional load? That doesn't sound cheap to me, but sounds smart.
 
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Old 08-17-11, 06:58 PM
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I don't know what the drop is capable of. Maybe it's fine. But the reason I increased my service was because I increased the load. I would guess the drop from the pole is no newer than the late 70's when the last panel was put in. It's obviously working ok so far. I don't know if a larger drop would make a difference, but the lights do dim when the a/c or any of my machinery is turned on. At what point do they know that the load has increased? When the wire melts and drops on both my vehicles in my driveway?
 
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Old 08-17-11, 08:28 PM
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Today 09:58 PMdrooplug
I don't know what the drop is capable of. Maybe it's fine. But the reason I increased my service was because I increased the load. I would guess the drop from the pole is no newer than the late 70's when the last panel was put in. It's obviously working ok so far. I don't know if a larger drop would make a difference, but the lights do dim when the a/c or any of my machinery is turned on. At what point do they know that the load has increased? When the wire melts and drops on both my vehicles in my driveway? .
I think the lights are dimming because the transformer is too small, and they won't know when the load has increases until the drop welds together and blows the xfrmr.
 
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Old 08-18-11, 05:23 AM
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The power company here wants to see demand load paperwork on a service increase so they know if the load will be increased and will check to see if their infrastructure needs an upgrade.
 
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Old 08-18-11, 04:04 PM
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Originally Posted by Justin Smith View Post
I think the lights are dimming because the transformer is too small, and they won't know when the load has increases until the drop welds together and blows the xfrmr.
Lovely. If it was because of the transformer, wouldn't it dim my neighbors lights as well?
 
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Old 08-18-11, 06:02 PM
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At what point do they know that the load has increased? When the wire melts and drops on both my vehicles in my driveway?
They have three ways of knowing the load has increased that I am aware of. One is to consult their crystal ball, the second is when you tell them you are increasing your load and the third is when they come looking for who is responsible for frying their transformer so they will know who to send the bill to.
 
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Old 08-18-11, 06:06 PM
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the lights do dim when the a/c or any of my machinery is turned on.
Lights dimming momentarily when a large load comes on is fairly common even in new homes.
 
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Old 08-18-11, 08:14 PM
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Guys and Gals we have wondered off topic just a bit and maybe we should wait for a response from the O/P.

To answer your question, I'm referring to the service main coming in from the street (150 Amp) to the main panel
Vaduke2005 how do you know it is 150 amp? You are talking about the wires from the pole to your house aren't you?
 
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Old 08-18-11, 09:22 PM
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I think he's talking about the SE cable.
 
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Old 08-18-11, 09:54 PM
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If he is then we need to know the size of the SE cable and if Al or Cu.
 
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Old 08-19-11, 04:13 PM
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Originally Posted by Justin Smith View Post
I think he's talking about the SE cable.
He speifically stated SE cable was rated at 150 amps in the first post.

Is it a problem to install a 200A Circuit Breaker panel w/an existing 150A entrance cable.
In the next post, he specifically calls out the service coming from the street.

I'm referring to the service main coming in from the street (150 Amp)
I think he's referring to both service cable and the service drop.
 
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Old 08-19-11, 08:17 PM
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I wouldn't worry to much about your drop. That's the poco's problem. If you have 150A SE# cable protected by a 200A breaker, then you have a problem. You will either need to reduce the main to 150A or replace the SE cable and meter pan to 200A.
 
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