110 and 220

[tom baker]

"110" and "220" are terms still in common use, althought tecnically incorrect. As an example, a home owner wants a 220 welder outlet. I suspect 110 and 220 were system voltages from early days of the NEC, if so about when did the NEC stop referencing 110 and 220? I have a motor, still in use, installed during WWII during war housing construction, that is rated 220/440.

 

[bennie]

Re: 110 and 220

Tom: The open circuit line voltage in the 40s was 115/230 nominal. The closed circuit voltage at the utilization equipment was 110/220 nominal.

The line voltage was changed to 120/240 volts in 1981. The terminal voltage became 115/230 volts.

My voltage records go back to 1899. The 115/230 voltage was adopted around 1918.

The reason for raising the voltage in 1981 was to sell more power

 

[charlie]

Re: 110 and 220

The reason for raising the voltage in 1981 was to sell more power

Bennie, you really know how to hurt a guy.

The real reason is to permit longer runs without having excessive Vd and to permit existing transformers to run a little cooler. Remember that the majority of our load is motor load. At the time this was done (before 1967 which is when I really got started in the electrical field) the 33 kV sub-transmission was raised to 34.5 kV and our 4 kV became 4.16 kV.

Somewhere around that time, IPL started its conversion program to convert the entire system to 13.2 kV (we are still working on that).

Bennie, to be fair to you, I think it was changed a little at a time across the country. It was only 25 years ago (give or take a little) that we converted from 460/265 to 480/277 volts. We would give our customer's service with the standard 480 volt transformers but buck the voltage by 5%.