Brand new home, with two service panels.
Typically, I call this 300 amp service, when there are (2) 150 amp panels.
However, they are both fed with the same service conductors from the meter, which are 3/0 aluminum.
So this is really only 175 amp service…
Does this affect the functionality of having two 150 amp panels? And should this be called out as being undersized feeders, since the panels together could technically pull 300 amps?
Those look like fine strand, tinned copper not aluminum conductors between the meter and the bus for the two service disconnects (those are copper crimp terminals). They’re also factory installed so you would go by the amp rating of the meter main based on the nameplate from the factory. Can you find a model number for the meter main?
Also these meter mains with the second breaker being back-fed are often used for solar, was there a PV system present? Here’s an example of the nameplate from an Eaton “solar ready” panel.
Thanks. I was wondering about that fine strand.
It was two service panels, no solar.
I didn’t get a close up of the label like I normally do… this picture is zoomed in
Looks like it could be a 200 amp meter main. The only way to know if it’s large enough is to do a load calculation. The fact there are 2-150 amp breakers and sub-panels is irrelevant if the load calculation is 200 amps or less.
Thanks again!
I’ve never added them together. Isn’t it two 150amp services? The services are not combined in any way. They are separate even if to the same building.
If the meter enclosure and the service conductors to the meter are rated for 200 amps then I would call it a 200 amp service.
But if both disconnects are fed independently from the meter, would you technically call it 300 amp service?
Hypothetically (we don’t know the size of the service conductors or the meter panel) if the conductors feeding the meter and the meter panel are only 200 amps can it be a 300 amp service? Technically it could draw 300 amps due to the two 150 amp service disconnects but would it actually be a 300 amp service if the conductors and equipment ahead of the service disconnects are not rated for 300 amps?
I’ve been calling that twin 150A services, Plans I’ve read call it 300A. Interesting input from Robert as usual.
Stock? 
