Very old elevators, still in original form

[Telecolor 3007]

Originally Posted by dieseljeep

Open delta was used when the user only need a three phase source for small loads. Now, 120/208, "Y" configuration is common! Also, very common in apartment buildings, even if they don't have an elevator!
More later!

120/208 Volts was also used in Bucharest. 220/380 Volts where introduced in the villages (nowdays most of them are part of the city) sorrounding Bucharest. Later, the voltage was switched in Bucharest too. So when the voltage swtiching was made, I wonder if they made a recoling ot the motors of the elevators from the buildings who previously used the lower voltage.

[dieseljeep]

[QUOTE=Telecolor 3007;3251801]120/208 Volts was also used in Bucharest. 220/380 Volts where introduced in the villages (nowdays most of them are part of the city) sorrounding Bucharest. Later, the voltage was switched in Bucharest too. So when the voltage swtiching was made, I wonder if they made a recoling ot the motors of the elevators from the buildings who previously used the lower voltage.

A motor designed to run on 208 volts will generally be OK on 220 volts. It'll draw a little more power and will produce slightly more torque.
The firm I worked for offered 208/220/440 volt motors.

[Telecolor 3007]

208 Volts was the 3 phase of the 120 Volts. Can an 208 3 phase motor be connected to 1 phase 220 Volts?

[dieseljeep]

Originally Posted by Telecolor 3007

208 Volts was the 3 phase of the 120 Volts. Can an 208 3 phase motor be connected to 1 phase 220 Volts?

A three phase motor will not run on single phase.
They used to make a convertor to run a three phase motor on single phase, but with reduced torque. Unbalanced current on the artificial phase.

[Electronic M]

Originally Posted by dieseljeep

A three phase motor will not run on single phase.
They used to make a convertor to run a three phase motor on single phase, but with reduced torque. Unbalanced current on the artificial phase.

Now a days VFDs do the job....Full wave rectify into a BIG capacitor bank then invert the DC into 3 phase.

[dieseljeep]

Originally Posted by Electronic M

Now a days VFDs do the job....Full wave rectify into a BIG capacitor bank then invert the DC into 3 phase.

I was going to mention those, but I had to leave the website.
Larger VFD's still need three phase power. They make smaller VFD's for single phase, lower voltage, 120/208/240 volts, probably a maximum of 3 HP (2.2 KW). They work great.

[kf4rca]

There used to be a company that advertised on one of the top radio stations here for sales and repair of VFD's. Most of the listenership had no idea what a VFD was. Those of us who are techies speculated that the ads were probably trade-outs for the station. Station transmitters use big motors whether they are air cooled or water cooled. So, if the station aired the ads, they could get their VFD's repaired for free.

[old_coot88]

I manage a building in San Fran that was built in 1907. The Otis elevator is original to the building and serves 6 floors including the basement. It runs 24/7, a "working museum piece", serviced once a month by contract. Oldest patent date on the data plate is 1889. It's a birdcage type with pantograph doors just like in the movie Titanic (where the steerage people were trying to break through). Runs on 230V DC and PG&E has a rectifier station supplying DC exclusively for these old elevators of which there are quite a few in the city.

[kf4rca]

There's a modern glass elevator at the Peachtree Plaza Hotel in downtown Atlanta.
https://www.youtube.com/watch?v=yQ1LDAK4r4I
There's a rotating restaurant at the top called the Sundial. But I understand they turned off the rotating after a serious accident.
Our station had a microwave relay on the top (2 GHz in and 13 GHz out) for ENG uses. Other stations had equipment there too.
From time to time we had to reset the controller up there and it was an odyssey to go there. It was so busy in the daytime, you might wait an hour to get an elevator. And then there was the nightmare of parking.
So our guys would go down there in the middle of the night when it wasn't quite so busy.
An added little bit of excitement was if you had to get on the roof. There was so much RF up there that when you opened the hatch, it would pull a 2 inch arc! But I never felt anything.