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Want to upgrade home from 200A to 400A service

12K views 78 replies 17 participants last post by  Bugman1400 
#1 ·
I am looking to educate myself on what's involved with upgrading my home service from 200A to at least 400A (I live in the US) to run some very power hungry computer equipment. By my basic calculations, I am currently pulling 170+ amps continually (total watts are over 16,000).

Some questions I have:

1)what is involved in actually upgrading capacity? I have a 200A meter, I will be calling my electric supplier as I understand they replace/maintain those. So, I assume I ask them to put a 400A meter in? (I have a 400A panel currently).

2) what is the max continuous use of a 200A meter? I've learned I shouldn't run more than 18A continuous from a 20A breaker/outlet. Same goes for the meter?

3) the computer equipment can handle up to 240v, is it possible to somehow utilize 220/240v, thus reducing the amps each computer uses? (different plugs would be needed but that's not an issue).

4) Is my current situation considered unsafe?

I greatly appreciate any feedback
 
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#2 ·
I am looking to educate myself on what's involved with upgrading my home service from 200A to at least 400A (I live in the US) to run some very power hungry computer equipment. By my basic calculations, I am currently pulling 170+ amps continually (total watts are over 16,000).

16000 W is only 66.6 Amps @240V or 133.3 Amps @120V

Some questions I have:

1)what is involved in actually upgrading capacity? I have a 200A meter, I will be calling my electric supplier as I understand they replace/maintain those. So, I assume I ask them to put a 400A meter in? (I have a 400A panel currently).

POCO's don't maintain meter sockets. Why do you say you have a 400A panel? That would be VERY odd for a residential service.

2) what is the max continuous use of a 200A meter? I've learned I shouldn't run more than 18A continuous from a 20A breaker/outlet. Same goes for the meter?

A load calc would need to be done, but generically 160A.

3) the computer equipment can handle up to 240v, is it possible to somehow utilize 220/240v, thus reducing the amps each computer uses? (different plugs would be needed but that's not an issue).

You would still be pulling the same at either 120V or 240V. Say you have a 10A 120V load. If you put that same piece of equipment on a 240V circuit, you have 5A per phase of the service, but that still equates to 10A on your service...you are still billed for 10A by the POCO.

4) Is my current situation considered unsafe?

I don't think you are analyzing this correctly, so it's hard to say.

I greatly appreciate any feedback
Answers in red
 
#3 · (Edited)
Thank you here are a few clarifications -

I am currently running about 21,000 watts continuous, not 16k (my math was off). I had an electrician come and put a bigger panel in, I'm pretty sure it's 400A but I can double check.

It looks like I'm running over the "safe" 160A currently (all the machines are running off 120v outlets). How "dangerous" is this?

I'm mainly trying to run as many machines as possible with my service, I am not sure if utilizing 240v allows me to do this. if it's just 6 to a half dozen, I won't pursue this option further.

Assuming I have a 400A panel, it looks like the "bottleneck" is the 200A meter. Is this correct, and can any licensed/competent electrician upgrade this?
 
#4 ·
As far as power goes a watt is a watt whether it's 12 volts or 240 volts. Generally an upgrade requires larger service conductors from the utility service drop to the meter and larger conductors from the meter to the panel. It could be that your electrician may have up sized the conductors from the meter to the panel. Different POCOS have different requirements for 400 amp services. Some allow a 320 amp socket while others require a CT(current transformer) cabinet ahead of the meter.

Sorry kbuz, I overlooked your answer to # 3.
 
#7 ·
It is HIGHLY doubtful that you have a 400A panel. No real electrician in his right mind would replace a 200A panel with a 400A without doing a service upgrade.

I also agree with Kbuz, you are not thinking this correctly. HOW are you measuring wattage? And amperage?

I also highly doubt you are taxing a 200A service with computer equipment in a home. Many folks have the misconception that even a room full of computers will overload a service.
Just exactly are you running? A server room? Laser printers?
"Some very power hungry computer equipment" is extremely vague.
 
#14 ·
I am measuring wattage by kill-a-watt type device, measured at the plug. So one unit is pulling ~2 KW at the wall, divided by 120 to get ~17 amps. All the computer equipment totaled is 21+ KW. This is just the computers - not accounting for any "normal" home use.
So if I'm understanding this right, my 21 KW are only using ~88 amps at the street? Which I don't quite understand because each unit on it's own is using say, 2000/120 = 17 amps at the wall, so 17 amps x 10 units = 170 amps pulling from the 200A panel (all the units are hooked up to the same panel). Again, this is my understanding of it.
I do not understand how the 240 volts is split into 120 once it reaches the house, and maybe that's where I'm getting things confused.

My concern was that I was reaching capacity or running things too close to their safe limits.
 
#18 ·
I did not measure anything at the meter - the only thing I have measured is each unit, and they pull 2 KW at the wall. I multiplied this out to get total watts used for the computers only. I could probably reverse calculate it, knowing my electric bill before these computers started running.

but that 88 amps at the meter was more a question, as my total (computer) use is again, 21 KW.

I guess it boils down to this - if I were to gauge my usage on a scale from "empty to full", where would I be right now, knowing I have a 200A meter, 200A panel, and 21 KW being pulled from that panel?
 
#17 ·
Let's try this again. At the meter, you have 240 volt service, which consists of two 120 volt legs. So if you are pulling 88 amps at the meter, the total wattage is 88 * 240 = 21,120 or 21 KW. Each individual computer actually draws 17 amps at 120 volts, for a total of 17 * 120 = 2,040 watts = approximately 2 kw per computer.

As to how 240 gets split into two 120 volt legs, each leg is 120 volts leg to neutral. You can think of one leg as +120 volts and the other leg as -120 volts, so between the legs you get +120 - (-120) = 240 volts leg to leg. The panel is set up with two busbars, one for each leg, so the busbars are 240 volts bar to bar, or 120 volts bar to neutral. You get either 240 volts or 120 volts on your circuit based on the type of breaker you put in.
 
#21 ·
Got it. So is there a way for a n00b like me to tell what type of breaker my electrician put in (and I'm assuming you mean the main breaker at the top of the panel)?

worst case I have a 120 volt breaker, and that means I'm approaching capacity of the panel, correct?
 
#24 ·
You have 2 120v legs from the utility through the meter to your panel. Loads that connect to both get 240 volts. Loads that are connected to either one and neutral get 120 volts. If you look at a 200a service and think 120v x 200 = 24,000 watts you are mistaken, it's actually 240v x 200 = 48,000. Post pictures of your meter and service and it'll be easier to tell you what you actually have.
 
#30 ·
You see the breaker at the top of the panel labeled 200A? That is a 200A, 240 volt breaker, so you have a 200A service, with a total capacity of 200A * 240V = 48,000 watts = 48 kilowatts (kw). In order to figure out how much spare capacity you really have, you need to do a load calculation on all of the devices and lights attached to your panel. But your electrician will be pleased to do this for you, as part of any required upgrade in service. Anyone who can afford 21KW worth of computers can surely afford an electrician to do the necessary work.
 
#54 ·
Well thanks for all the feedback everyone, I think I have a better understanding of everything....
Apparently I have 2x 200 amp panels, each on a separate "line" from the meter, which means 400 amps. My electrician said it didn't matter that the meter was a 200 amp meter. I am hoping he isn't wrong, should I start drawing more than 200 amps continuous.

Also, my electrician agreed with the person here who mentioned that I basically have 200 amps "per leg" of 120 volts, so my 174 amps of draw right now is essential half of that, since it's split between each voltage leg.

So, in conclusion, it appears I'm not quite as close to capacity as I thought I was. Thanks again everyone for helping me better understand this.
 
#55 ·
.
Apparently I have 2x 200 amp panels, each on a separate "line" from the meter, which means 400 amps. My electrician said it didn't matter that the meter was a 200 amp meter. I am hoping he isn't wrong, should I start drawing more than 200 amps continuous.
You don't have a 400 amp service, if your meter is only rated for 200 amps, that's all you have. You can have as many panels as you want, but the fact remains, your service is only sized for 200 amps.


.Also, my electrician agreed with the person here who mentioned that I basically have 200 amps "per leg" of 120 volts, so my 174 amps of draw right now is essential half of that, since it's split between each voltage leg.
It depends on how the circuits are split up, if all your heavy loads fall on the same leg, then you could trip the main... Of course, your whole setup sounds bizarre.


.So, in conclusion, it appears I'm not quite as close to capacity as I thought I was. Thanks again everyone for helping me better understand this.
I still think it's WAY over your head.
 
#57 ·
Perhaps it this beast, am Oracle/SUN T5-8. I have a couple in my DataCenter (commercial). 1028 cores (128 processors), 2 Terabytes of RAm. At full load it takes 21000 watt at 240/208 . It also generates 25,000 BTU of heat per hour. and should only be installed in a DataCenter environment. It's loud enough that it sounds like a small aircraft. I am sure the OP's wife would love this screaming banshee in the basement.
 
#58 · (Edited)
I also think its grow lights. Typically, the next level of residential service is 320A and usually on large houses. If your house isn't at least 6000 square feet then your electric company will certainly, in cooperation with the local police, turn that info over. I typically let my supervisors know the visual size of the house if it contradicts what it says on the work order when connecting services over 200A. I've done that twice. And it was because the house was typical size but, had junk cars and guard dogs out front and 5500 sqft written on the work order.

400A service is usually for commercial and requires CTs.

Besides, you can't plug in the 2 - 1100 watt power supplies into the same outlet or on the same circuit.
 
#63 ·
starfighter said:
I agree- this is beyond my skill level, which is why I came here. I need help and advice, and I'm taking as many approaches to getting in the know as I can. the high-draw circuits are split between the legs, so all good there. But you're saying if I have two separate 200A panels not connected to each other (each with their own 200A service), I'm still at 200A total because my meter is 200A? hypothetically, do you know what would happen if I drew more than 200A through my meter?
I would have to see a picture of your service to give you an accurate answer to your question.
 
#65 ·
I am no sparky but if you try to draw more then 200 amps through a 200 amp service you trip the breaker and power turns off. Man for some one saying they are running computer equitment and such. boggles my mind as to how ignorant one can be. Still say this is a grow opperation. no person living in a house needs that much power.
 
#67 ·
Since this thread has spun off into space, I will add the little I know about the fuses on the pole top transformer. A lineman told me they are typically 15 amp on a 12000 volt line. These are just there to protect the power companies lines. The 240 volt customer side of the transformer gives a turns ratio of 50:1. 15 amps times 50 is 750 amps. That will burn down the house drop, into molten metal, long before the fuses on the primary side will blow. If I got this wrong please correct it.
 
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