Service Upgrade question

Status
Not open for further replies.
D

dasan384

Member
Location
Miami, Florida
First of all, I want to thanks everybody on this forum because a lot of time I got many solutions to my problems just reading the forum. I have a question and I could not find the anything related here. I have to do a service upgrade to a huge house here in south Miami. The Power Company has been upgrading the area from single phase to three phase, so the owner of the house wanted to take advantage of this and upgrade his service from single phase 120/240 3 wire to 3 phase 120/208, 4 wire. They are going to have a new AC system which is going to be 3ph. 208v and the new kitchen equipment is going to be also 3ph 208. Right now they have the meter one main that goes to a gutter and then 8 120/240V panels to feed the entire house. I was planning to change the meter and install a Main Distribution Panel 120/208v, from there I want to go to an 120/208 3 phase AC/Kitchen Panel for the new equipment and then from the MDP to each 120/240 panel. Do you have any additional suggestion? The question I have is that some of the equipment they are not planning to change such as dryer, water heater and some other stuff are in 240V, so what would happen with this stuff when I change the service? because now is 120/208 I am confused with this. If anybody can help me thanks. If you need more info let me know.

Thanks in advance
 
The water heater will still function, but it will only operate at 75% of its rated heating capacity. The dryer might have a problem, as its motor will be drawing about 15% more current than normal. Also, its heating capacity will drop to 75%, so the owner will not be happy with its operation. Generally, you should not serve any component with a different voltage, unless the manufacturer's published manual or the nameplate specifically says it can work at a range of voltages. Reference NEC 110.4.

Otherwise, your plan seems reasonable. Welcome to the forum.
 
charlie b said:
The water heater will still function, but it will only operate at 75% of its rated heating capacity. The dryer might have a problem, as its motor will be drawing about 15% more current than normal. Also, its heating capacity will drop to 75%, so the owner will not be happy with its operation. Generally, you should not serve any component with a different voltage, unless the manufacturer's published manual or the nameplate specifically says it can work at a range of voltages. Reference NEC 110.4.

Otherwise, your plan seems reasonable. Welcome to the forum.
Click to expand...

[FONT=&quot]Thanks for the response. I explained that to the owner, and he is aware of that. So just to be sure, from my Distribution I am going to have a 3 pole breaker for my ac panel which is going to be 120/208, and a 2 pole breaker for each existing 120/240 panel Correct?

Thanks [/FONT]
 
dasan384 said:
Thanks for the response. I explained that to the owner, and he is aware of that. So just to be sure, from my Distribution I am going to have a 3 pole breaker for my ac panel which is going to be 120/208, and a 2 pole breaker for each existing 120/240 panel Correct?

Thanks
Click to expand...

That is correct. :thumbsup:
 
Could he use a buck/boost transformer for the two appliances in question and get a better result? I've had to use them on a few tanning beds that required a higher voltage.
 
Status
Not open for further replies.
Top