Eletrical 100 amp is it enough

[IPWitan]

I am in the process of buying a house. I just learned that the house is 100 amp and not 200. Since having a house that isn't 220 volts is completely new to me, I question whether this is enough for a reef tank and other daily things. I have a standard 90 gal setup - nothing fancy. I don't know how watts, volts, and amps interrelate.

6x54 t5 lights 324 watts
200 watt heater
mag 5 (est 45 watts)
2 mj1200 - (est 10 watts x 2)

In running this setup with a computer, printer, stove, etc., will I run into problems. I was told that the dryer and stove are electric, and 220 volts ready (I thought they REQUIRED 220, but I guess not!) The inspector suggested that I would be fine with the finish tank, but I am not sure if he appreciated how much energy is used.

Any help would be appreciated. And if I need to have the electrical upgraded to 220v, I need to get the order in place now!

David

 

[Takara]

I'm sure Don will have to chime in, but when I spoke with him he told me the difference was night and day when he switched to 220 service.

 

[IPWitan]

I hope he explains, because I simply do not understand the concept at all, other than it hurts like hell when zapped.

David

 

[DoctaQ]

volts*amps=watts

110*100=11000watts

 

[George]

I am in the process of buying a house. I just learned that the house is 100 amp and not 200. Since having a house that isn't 220 volts is completely new to me, I question whether this is enough for a reef tank and other daily things. I have a standard 90 gal setup - nothing fancy. I don't know how watts, volts, and amps interrelate.

6x54 t5 lights 324 watts
200 watt heater
mag 5 (est 45 watts)
2 mj1200 - (est 10 watts x 2)

In running this setup with a computer, printer, stove, etc., will I run into problems. I was told that the dryer and stove are electric, and 220 volts ready (I thought they REQUIRED 220, but I guess not!) The inspector suggested that I would be fine with the finish tank, but I am not sure if he appreciated how much energy is used.

Any help would be appreciated. And if I need to have the electrical upgraded to 220v, I need to get the order in place now!

David

You're confusing amps with voltage. With 100amp service you still have 240 volts coming into the house on 2 120volt lines. That being said, you should get 200amp service.

The setup you listed is using about 5 amps.

 

[JayM]

the house will run on a 100 amp service, but it would benefit from an upgrade. It shouldn't be a deal breaker

 

[kevinpratt823]

You should be fine, like George said, most likely it is a 220v/100a service, a straight 120v service is extremely rare. The only limiting factor is circuit breaker space, as it prob only has 20 spaces. I have a 100a service and I run a 450gal reef system on basically 2 dedicated circuits, as well as a 180gal FOWLR on my reg living rm outlets. This being said, your service is prob 220v at 100a which is actually 22000watts, a single pole breaker is 120v, a double pole is 220v. Again, the real limiting factor is breaker space. comment removed

 

[IPWitan]

Thank you all for the information as it is very helpful.

Let me see if I have summarized this correctly. Running the fish tank, stove, microwave, etc. shouldn't be a problem.

[Assumptions to follow] The 100 amp system only has x number of breakers. As such, I MAY need another breaker, which means that I MAY need to upgrade to 200 amps. Adding the extra 100 amps gives me a whole bunch of extra breakers.

How do I know if I need to upgrade? My knowledge suggests that if I trip the breakers, then I need a separate (dedicated) breaker. Thus, can I assume, then, if I don't trip the breaker, then I am fine?

Also, is it fair to assume that I can run everything in the house as long as I don't exceed 100 amps (11,000 watts) of concurrent usage?

Thanks again.
David

 

[stingythingy45]

I run 2 250 watt halides,2-54 watt t5s multiple PHs,return pump(Gen x pcx-40),fridg,micro,stove ect,TV...ect.. on 100 amp service(fuses) with no issues.One 250 watt heater and 1- 100 watt heater.
What makes you think you'll have problems with your house?

 

[IPWitan]

why do I think I need an upgrade...because every house I have ever owed had 200 amp service and the inspector didn't know, but thought it could be an issue.

Also, there is currently (a little pun) forced hot air for heating. Ideally, I would like to add an ac unit to it. I was told that if I did that, then I would likely need to upgrade the power. Again, this may not be accurate.

The reason for the AC is the following:
1 - appease the wifey. She doesn't like it hot in the summer, hence why we moved from Miami
2 - I have zero ac window units, so will need to spend money on something to keep the place cool. Don't like window units, moving, blocking window, etc.
3 - Must cool the fish tank in summer, might as well cool the room too!
4 - Very nice tax credits for units, if energy efficient.

 

[eric-c]

Most house that have a 200A service don't even use half. You would be surprised that after doing calculations to figure the service size for a residence (which is required for new construction by the utility co.) many homes will calculate at 80-95A. This is with electric stove, micro etc. The standard for a new home is 200A, not because they need it but we (electricians) were always taught to plan for future loads. Adding your 90 setup will not require a service upgrade, however adding an A/C unit might. It might be worth paying an electrician to give you a calculation of your house and what the demand will be for your new A/C unit. Spending a little $ now could help you save $$$ by not just upgrading the service. IMO

 

[cujo6984]

how large is the house??? you would be supprized what you could run on a 100 amp service my house is pretty big and i have 15tons worth or electric heat pumps i max at about 130 amps and thats with 20 amps going to the fishroom you should be fine unless your planning on running the electric dryer, stove and full a/c at the same time

 

[stevenp]

Can't you use piggyback breakers to fit more circuits in the panel? I remember Gustavo did this after his electrician found that he was nowhere near pulling the max 100amps on his panel, yet he had no open space for anymore breakers.

 

[cujo6984]

yes you could


the biggest thing you need to look at is max amps you will need to know what size a/c you will need and what is your max amps now

 

[Mr. Leemr]

Its funny when you actually show someone the actual amps being drawn on each leg of their service during norml operating conditions with a clamp on amp probe usually no where near what they ever expect, usually between twenty to thirty amps.

 

[cujo6984]

yea it usually alot lower than they think now go turn everything on thats a different story lol

 

[IPWitan]

The house is not big (at least compared to my neighbors) at 2600 sq including the finished basement. The posts make me think it will be ok for now. And while the stove is currently electric, we would like to switch it to gas in time...which will free up amps!

 

[cujo6984]

if you are planning a gas stove what about the dryer? you should have no problems

 

[eric-c]

Though taking an amp reading in "normal operation" is nice, the actual calculation you need to go by is a little more involved. This calculation is based on the NFPA 70/NEC.

 

[emabie]

You should be just fine as long as the circuit you put the tank stuff on is not all ready getting maxxed out. If so you may end up tripping the breaker for that circuit. In this case you will need to add a breaker. If the box is full then you can add the piggyback breakers mentioned above, ONLY if you panel is rated for them.

I don't think a tank makes a 200a service upgrade justifiable.

Central AC may though.