aks20000
Member
- Location
- San Francisco
- Occupation
- engineer
I have a 200amp service in 1992 built 3375 sq ft home.
The outside main panel , connected to the meter, appears to be MLO panel with six spaces for circuit breakers.
It has two 100 amp CB, one feeds a sub-panel in the garage and the other feeds two outdoor AC condenser unit.
Garage panel is also 200 amp MLO panel and has many CBs for the various branch circuits. Two major load here are Electric Dryer and Oven.
I have Tesla solar installed thru city permit and its back-feed is connected to this panel using 50 amp CB, which is treated as supply side connection I think.
There is no other CB in this panel.
I now need a feed for Tesla wall charger and an electrician suggested to install it on the outside main panel as a 4th 60 amp CB.
My questions in this regard are,
1. I don't see any upstream overcurrent protection in outside service panel. There could be one between the panel and the meter , but I can't see that as panel is connected to the meter. It's a Square D panel. Adding a 60 amp CB will take the total of breaker amps to 260. Is this permitted by the code ? I understand that panels are routinely overloaded with many CBs provided total load calculation is within amp rating of the service. But in this case, I don't see any upstream overload protection - so technically I can run the three branches at full capacity of 260 amp causing my feeder wire to melt.
2. If answer to Q1 is not code compliant, then what are my options to add this new load to this panel without replacing it completely . Is it possible to add a upstream 200 amp breaker between the meter and the panel to limit max draw to 200 amps .
3. My sub-panel in the garage has ample of space and not overloaded. It feeds a dryer , a oven, microwave, two indoor hvac blowers and lighting loads. I don't have any water heater, spa or pool heating . when I checked with the same electrician ( Tesla approved and highly rated ) to put the charger on this panel, he advised against doing it as a typical practice. Is it true or has any downside in the context of my electrical load situation described above ?
4. To confuse me further, another Tesla approved electrician suggested just the opposite , that wall charger load can't be connected to outside MLO service panel and should be added to garage sub-panel.
Your advise will be greatly appreciated.
BTW, how do you deal with Tesla Solar for the sticker , that they have put in the outside main panel saying "Caution, Add no new load " . My first electrician says that they routinely strap these warnings and it makes no sense.
The outside main panel , connected to the meter, appears to be MLO panel with six spaces for circuit breakers.
It has two 100 amp CB, one feeds a sub-panel in the garage and the other feeds two outdoor AC condenser unit.
Garage panel is also 200 amp MLO panel and has many CBs for the various branch circuits. Two major load here are Electric Dryer and Oven.
I have Tesla solar installed thru city permit and its back-feed is connected to this panel using 50 amp CB, which is treated as supply side connection I think.
There is no other CB in this panel.
I now need a feed for Tesla wall charger and an electrician suggested to install it on the outside main panel as a 4th 60 amp CB.
My questions in this regard are,
1. I don't see any upstream overcurrent protection in outside service panel. There could be one between the panel and the meter , but I can't see that as panel is connected to the meter. It's a Square D panel. Adding a 60 amp CB will take the total of breaker amps to 260. Is this permitted by the code ? I understand that panels are routinely overloaded with many CBs provided total load calculation is within amp rating of the service. But in this case, I don't see any upstream overload protection - so technically I can run the three branches at full capacity of 260 amp causing my feeder wire to melt.
2. If answer to Q1 is not code compliant, then what are my options to add this new load to this panel without replacing it completely . Is it possible to add a upstream 200 amp breaker between the meter and the panel to limit max draw to 200 amps .
3. My sub-panel in the garage has ample of space and not overloaded. It feeds a dryer , a oven, microwave, two indoor hvac blowers and lighting loads. I don't have any water heater, spa or pool heating . when I checked with the same electrician ( Tesla approved and highly rated ) to put the charger on this panel, he advised against doing it as a typical practice. Is it true or has any downside in the context of my electrical load situation described above ?
4. To confuse me further, another Tesla approved electrician suggested just the opposite , that wall charger load can't be connected to outside MLO service panel and should be added to garage sub-panel.
Your advise will be greatly appreciated.
BTW, how do you deal with Tesla Solar for the sticker , that they have put in the outside main panel saying "Caution, Add no new load " . My first electrician says that they routinely strap these warnings and it makes no sense.