[sfltech]

Hi all,

I am in need of some guidance in regards to upgrading my home's electrical service.

Here goes nothing:

I ordered a tankless water heater for my home, after it arrived I realized that I need at least 150 amp service in order to use it. I was not sure the power size my home had so I opened up the meter box and discovered that it's rated for 200 amps max, however the cable from the street is 2/0 aluminum, this is rated for max 150 amps. Based on this I assume I can get 150 amps from the street, however the the panel attached to the meter base contains two main breakers rated at 50 amps each(so 100 amps total going inside the house). I think the panel itself is an 100 amp panel and I am not sure if it would be ok to just throw an 150 amp main breaker combo in there? From what I understand a panels rating mainly refers to the busbar's ability to handle amperage and the panels overall thermal properties under load, so I am tempted to use an 150 amp main breaker setup and just monitor the internal temperatures for a bit under full load to see if it hold's up, instead of replacing the panel with one rated for 150 amps.

This is what the panel looks like:

In summary my questions are:

Is this an 100 amp panel for sure or could it be an 150 amp panel that just has 100 amp main breaker?

If this is an 100 amp panel can I use an 150 amp main breaker if I monitor the busbar temperature and make sure it's within safe limits?

Based on having 2/0 aluminum cable coming from the street into a 200 amp rated meter base is it safe to assume I can draw at least 150 amps from the street?

Sorry if this is a bit confusing, I am new to electrical work.

 

[joecaption]

#1, I'd never use an electric tankless water heater for a whole house!
Just not going to have enough make up water and cost far to much run.

 

[Jump-start]

Ok, that main breaker is a big no-no. It needs to go.

 

[Know A Little]

Ok, that main breaker is a big no-no. It needs to go.

Why do you say that?

While it is not something I would install, I do believe that is a UL listed assembly.

 

[rjniles]

Why do you say that?

While it is not something I would install, I do believe that is a UL listed assembly.

The 2 phases are not handle tied.

 

[Speedy Petey]

Why do you say that?

While it is not something I would install, I do believe that is a UL listed assembly.

It's not.
That was a Siemens panel with a parallel "quad" main breaker. Looks like two 2-pole breakers with a 4" wide handle tie. Some clueless person put two individual 2-pole breakers in as a replacement. Now each leg is on it's own breaker. That abomination is dangerous and totally hacked together.

 

[Speedy Petey]

Hi all,

I am in need of some guidance in regards to upgrading my home's electrical service.

Here goes nothing:

I ordered a tankless water heater for my home, after it arrived I realized that I need at least 150 amp service in order to use it. ....

.......

Sorry if this is a bit confusing, I am new to electrical work.

Did you not check the electrical specs before ordering this monster???

I have to honestly say, looking at that panel, and your level of electrical knowledge, your safest bet by far is to call in an electrician that knows what they are doing. Seriously.
You have a real mess going on there.

 

[Speedy Petey]

This is what the main should look like:

 

[lenaitch]

If the service is coming into the box at the lower right and the breakers at the top are the main service breakers, then there are distribution circuits in the same cavity which as far as I know is prohibited - maybe it was permitted at some point. I'm not familiar with the rules for main breakers at the meter and a separate distribution panel since I'm not sure it was ever allowed up here. Also, where are power cables at the bottom going?

 

[Jump-start]

Why do you say that?

While it is not something I would install, I do believe that is a UL listed assembly.

Its not, those are two Homeline breakers in a Siemens panel. The factor installed main was taken out of its listed assembly.

 

[Know A Little]

The 2 phases are not handle tied.

AHHHH I did not see that on the iPadSome body doing a little hackery

 

[Jim Port]

You may need an additional service just for the tankless.

 

[Know A Little]

The biggest complaint I have heard about the tankless is light flicker, when in use.

I wonder if there is a study showing the real cost savings.

Lastly from my understanding point of use tankless is a bigger savings than a single whole house and little to no wait for hot water and each single unit places less burden on your electrical service.

 

[jimn]

Ditto on electric tankless. I would never get the pay back. In fact it would probably cost me money. Between electricity plus delivery fee running about 16 cents /kWh , having to upgrade my strive to 200 AMP (which currently it's a properly wired 100 AMP system) plus the cost of the heater, plumbing, and electrical, I would be close to 4000 grand in the hole to start. I currently have an oil fired water heater and I burn about 100 gallons of oil a year.

Got that off my chest.

You really do need to get your electrical entry fixed no matter what you do. That is an abomination and as others have stated dangerous.

 

[sfltech]

This is what the main should look like:

Thanks for your help. Am I understanding correctly that if I put in a handle tied main breaker like the one above into the panel that will take care of the issues?

Also, can you tell me if my panel is rated for an 150 amp main-breaker?

 

[mpoulton]

It's not.
That was a Siemens panel with a parallel "quad" main breaker. Looks like two 2-pole breakers with a 4" wide handle tie. Some clueless person put two individual 2-pole breakers in as a replacement. Now each leg is on it's own breaker. That abomination is dangerous and totally hacked together.

Man, I wondered what I was looking at there. I didn't say anything because I figured I must have just been confused, but it sure looked like exactly what you're saying. I just didn't think it was physically possible to do that.

 

[sfltech]

If the service is coming into the box at the lower right and the breakers at the top are the main service breakers, then there are distribution circuits in the same cavity which as far as I know is prohibited - maybe it was permitted at some point. I'm not familiar with the rules for main breakers at the meter and a separate distribution panel since I'm not sure it was ever allowed up here. Also, where are power cables at the bottom going?

Here's a diagram! :smile:

 

[lenaitch]

Ok, so this is a mains breaker panel. But you have two distribution circuits in there. Up here main breakers must be physically separate from the distribution circuits (even if in same box). Maybe it's grandfathered compliant - others will know better.

 

[psgama]

That "panel" and I use the term loosely when describing what you've shown, Is an abomination. It is a total hack job and the whole thing should be replaced. No Electrician in their right mind will add your water heater without fixing that first, and no inspector will pass it. If you add an Electric tank less system to that, you're putting your household at risk of fire.

Can anyone tell if the main bus has been modified? Would a replacement Siemens breaker even still bolt to that bus?

 

[Speedy Petey]

Ok, so this is a mains breaker panel. But you have two distribution circuits in there. Up here main breakers must be physically separate from the distribution circuits (even if in same box). Maybe it's grandfathered compliant - others will know better.

No grandfathering required here. What you describe is a Canadian thing. In the US we don't have that rule.