[bugmenot]

My home is set up for 100 amp service. I'm wanting to install a tankless water heater, but my current setup can't handle it. Can I run another breaker box off the main cables from the main box, to give me another 100 amp service box? The new breaker box will then give me the needed 83 amps to run the water heater.

Thank you for your time in viewing and answering my question.

 

[Scuba_Dave]

Your main service is your main service
You can't exceed what isn't there
You would need to upgrade to a 200a service

 

[InPhase277]

Your main service is your main service
You can't exceed what isn't there
You would need to upgarde to a 200a service

As well as contact your power company to make sure the transformer and service drop can actually handle the new load without your lights and appliances browning out when it kicks on.

 

[bugmenot]

I was told that I could do this safely by bypassing the main breaker and connecting a new cable onto the main cable in the breaker box and carrying to a new box . I was told this by the man I purchased the water heater from, he said he advises people and shows them how to do it safely. He also added that the outside wires coming into the meter can handle the added amps.
I do know that if I tied into the main breaker and a load is added that my home would be browning out, but the man I spoke with today said that this would not happen since I'm bypassing the main breaker and daisy chaining the main cables going into the main box.

Thanks again for your time.

 

[Scuba_Dave]

Is your meter rated for 200a?
Will the wire from the power company handle 200a ?
Are you willing to pay the fine if you burn up the wire?
Are you able to rebuild your house if this starts a fire by overheating wires or something not rated for 200a?
Because your insurance company may refuse a claim if they find out you did something wrong. Maybe unlikely, but do you really want to risk it?

And, is your life insurance paid?
You are going to work on live 100a wires?

The man you talked to....he works for the POCO??
Will he insure you against damages if something goes wrong?
What does your electric inspector say?

 

[bugmenot]

Is your meter rated for 200a? DON'T KNOW
Will the wire from the power company handle 200a ? NOT SURE
Are you willing to pay the fine if you burn up the wire? HELL NO
Are you able to rebuild your house if this starts a fire by overheating wires or something not rated for 200a? ONLY IF INSURANCE PAYS FOR MY CURRENT HOME
Because your insurance company may refuse a claim if they find out you did something wrong. Maybe unlikely, but do you really want to risk it? I BELIEVE YOU

And, is your life insurance paid? YES, BUT I SHOULD RAISE IT
You are going to work on live 100a wires? NO

The man you talked to....he works for the POCO?? NO, HE WORKS FOR HIMSELF
Will he insure you against damages if something goes wrong? NO
What does your electric inspector say? I MAY SPEAK TO ONE SOON

I'm just looking for answering or the truth, that's why I'm here. I'm not going to jump into anything without first finding out all the facts for myself. I do appreciate the time you or anyone takes to help me and others out.

 

[InPhase277]

I'm just looking for answering or the truth, that's why I'm here. I'm not going to jump into anything without first finding out all the facts for myself. I do appreciate the time you or anyone takes to help me and others out.

The truth is, it doesn't matter to which side of the main you connect, if you put a large load on the system, your lights will dim. It sounds like the guy was trying to sell you a water heater. Likely, you will need to upgrade the size of your electric service, as well as the line from the power company. They may even need to up size the transformer, depending on what else is served by it. Best bet, get in contact with a reputable licensed electrician and the power company.

 

[COLDIRON]

Don't listen

BUG
Do not listen to the guy in the store. Have you ever heard a banana salesman yelling out rotten bananas for sale??:no:

You sound like you are almost doubling your electrical needs,
If you want to purchase and install the equipment you
must call a pro.

 

[Scuba_Dave]

Call your power company
It is possible they will say the outside wires can handle the load
But they need to approve the upgrade
They also need to verify that transformer can handle the additional load

I'm under the impression that a 200a meter would need to be installed

Do you have a main shut-off outside somewhere?
Around here everything is inside
In some cases I have seen a 200a min shut-off outside, then only a 100a panel after that. So in some cases you may have the power you need

But it needs to be verified 1st
Call the power company, they may or may not know
You will probably need an electrician to verify the setup if the power company can't come out & check it out

That 83a WH will use 83% of you existing power setup
One reason I won't even consider an electric tankless WH
And I have a 200a service !!

Can you use the tankless?
Yes, but your electric setup needs to be upgraded

 

[AllanJ]

What you are doing is having two main panels. I'm not sure whether this is permitted even if they are side by side. You need to be able to stand in one place and disconnect everything to the building; I'm not sure whether it has to be one switch/breaker/maneuver. I forget where but I saw a picture of a main panel with no main breaker but with three master switches, one for each of three subpanels.

More customary is installing a new main panel (here, 200 amps) and making your old panel into a subpanel.

I do not consider this a do it yourself project unless you have the meter pulled and the house de-energized. Accidentally shorting the feed wires upstream of the main breaker can cause a flow exceeding a thousand amps. Enough to melt and even vaporize wires and tools literally causing an explosion. Some cities require a separate permit for work upstream of the main breaker which is often categorized as "service" or "panel" work.

 

[rgsgww]

This guy must want to see your house burn down. You cannot do what he said.

 

[Addicted]

More customary is installing a new main panel (here, 200 amps) and making your old panel into a subpanel.

This sounds right.

I installed a 200 amp through feed panel (has a 200amp disconnect with just a few circuit breaker slots). It has lugs built in to feed into a subsequent panel (basicly the same as making your old pannel a sub-panel).

I believe you will need to separate neutrals and grounds in your existing pannel (now as sub panel), and feed that panel with 4 wires.

I "upgraded" from 100amp service to 200 amp service, but my external wire was not changed. The power company installed a new meter, but said my old overhead wire was OK.

 

[bugmenot]

Thanks everyone for your time and help, I decided to put off the installation and went out instead and bought a new 40 gallon water heater (natural gas). It is better to be safe than sorry!

 

[joel v.]

You made a good choice. I have heard that the electric tankless have some reliability problems. The natural gas ones are a bunch better

 

[COLDIRON]

Tankless

Just wondering why you didn't install a gas tank less in the first place??

I didn't know you had gas available or I would have answered the question different.

I guess I should have asked.