Contactors for 200HP Wye-Delta Motor Configuration

[drcampbell]

... there was a lever on the side of the panel, similar to the handle on an old slot machine. You would pull that lever and with a bang the motor would accelerate to full speed.
Would these shotgun starters have been a wye-delta starter, with a manually operated mechanism to switch from wye to delta? ...

Might have been, though I wouldn't think that a design requiring six wires down a deep well would have been the most economical.
(or maybe cable was cheaper and wells shallower back in the day, and it's an unfounded assumption based on today's economics)

A large handle would have been a good way to assure that the Y and Δ contacts never engage simultaneously and keep the control cabinet simple & economical, without using then-finicky time-delay relays or complex sequencing circuits.

 

[drcampbell]

... Did anyone do a single-phase equivalent (parallel/series connection)? I can't think of reading about any in the old books, seems like an autotransformer would work better there.

Hammond electric organs (c.1930s-1960s) had two manual switches (start & run) for starting what was almost certainly a single-phase subfractional-horsepower motor.

But because it was driving a toothed metal tonewheel to generate pitches, (speed-critical and near-zero torque requirement) I presume they used a non-self-starting synchronous motor.
Just guessing; never serviced one.

 

[GoldDigger]

Hammond electric organs (c.1930s-1960s) had two manual switches (start & run) for starting what was almost certainly a single-phase subfractional-horsepower motor.

But because it was driving a toothed metal tonewheel to generate pitches, (speed-critical and near-zero torque requirement) I presume they used a non-self-starting synchronous motor.
Just guessing; never serviced one.

A very good starting point. The only other interesting details I can add are tha that the starting function is a separate motor which you leave on briefly overlapping with the run motor. And that it is not just driving one tone wheel but a bank of ~90, one for each fundamental frequency. The shape of the teeth affects the harmonic content of the note. The precise tonal quality is set by mixing in other fundamentals.

I would guess that the starting motor slightly overspeeds the synchonous motor. letting it coast down into sync. But I really do not have much experience with synchonous motors except for our familiy's ancient electric clock. You spun up the motor with a hand knob.

 

[zbang]

I would guess that the starting motor slightly overspeeds the synchonous motor.

According to the M-series service manual, it does exactly that ("generator" is the tone generator)-

The procedure for turning on the organ is as follows: Push the "start'' switch
up (M-3, M-100) or in (M, M-2) and hold it for approximately eight seconds.
This allows time for the starting motor to bring the generator up to slightly
above it synchronous speed- While still holding the "start" switch, push the
"run" switch upward to its "on" position. This turns on the synchronous motor
and at the same time introduces a resistor in series with the starting motor
to reduce its power- Hold the "start" switch about four seconds longer and then
release it.

 

[kwired]

Back in the 1980's and 90's I worked for an irrigation company. We drilled wells, installed lineshaft turbine pumps, centrifugal pumps, pipelines, and center pivot sprinkler systems. I remember some old pump panels then that were referred to as "shotgun panels". They were propably 20-50 years old back then. I never worked on one or even opened the cover. But when you started it the motor would run at reduced speed. Then there was a lever on the dide of the panel, similar to the handle on an old slot machine. You would pull that lever and with a bang the motor would accelerate to full speed.

Would these shotgun starters have been a wye-dekta starter, with a manually operated mechanism to switch from wye to delta?

Back then we installed across the line pump panels up to about 125 hp. Abovethat we used RVAT panels, or Robicon Mark4 VFD's.

I would think it could been either wye-delta or part winding starting.

Either method would appear to be low speed in the start mode, but reality is they are lower torque in that mode and just can't accelerate the load as fast as run mode can. Either way the start mode should be very short duration as it's main purpose is to reduce initial locked rotor current, but there just isn't enough torque to allow it to remain in that condition for very long without excessive heating. Once transfer to run mode happens after just a little bit of acceleration has occurred it will have enough torque to accelerate to full speed much easier, but won't have same kind of surge in current as across the line starting will initially have.

 

[kwired]

Might have been, though I wouldn't think that a design requiring six wires down a deep well would have been the most economical.
(or maybe cable was cheaper and wells shallower back in the day, and it's an unfounded assumption based on today's economics)

A large handle would have been a good way to assure that the Y and Δ contacts never engage simultaneously and keep the control cabinet simple & economical, without using then-finicky time-delay relays or complex sequencing circuits.

Can't say what he had but around here wells over maybe 20ish HP are never submersible type. They are hollow shaft style motors located at the top of well casing and are above ground, they drive a shaft that runs all the way down to however deep the pump is situated in the well.

 

[Jraef]

…. I remember some old pump panels then that were referred to as "shotgun panels". They were propably 20-50 years old back then. I never worked on one or even opened the cover. But when you started it the motor would run at reduced speed. Then there was a lever on the dide of the panel, similar to the handle on an old slot machine. You would pull that lever and with a bang the motor would accelerate to full speed.

Would these shotgun starters have been a wye-dekta starter, with a manually operated mechanism to switch from wye to delta?
…

Those were / are called “manual compensators”, or more affectionately “one-armed bandits” because of their resemblance to a slot machine. In the bottom of the cabinet would have been a transformer in an oil tank, because it was an auto transformers starter, but using manual switches instead of contactors to step through the starting sequence in an open transition manner. Very archaic and it relied on a trained operator who knew when to transition from start to run by the sound of the motor. As those trained operators retired, the manual compensators were replaced because new operators were afraid of them.

PS:
Somewhere I have a video that I made in 2007 of an old operator at a pump station on the Sacramento River starting a 300HP pump with one of these. I was there to retrofit them with Soft Starters because whenever one failed, there was no way to repair them. The pump station operator was in his 70s and had lived at the station alone with his dogs for 40+ years. He had an old rotary dial wall telephone from the irrigation district so they could call him and tell him when to turn on pumps. It was quite the process because they were also not self-priming, so he had a vacuum pump that had to start first to fill the volute. But the vacuum pump had leather seals, so he had to manually add oil to them with an oil can while it was running in order to maintain vacuum. It was an insanely comical process to start each pump, and there were 4 of them. That’s the reason I took the video, because it’s something I had not seen in use for decades at that point. He said that he had no intention of retiring so he never needed to train his replacement, and resented the fact that my system was going to make it easier for someone else. I pointed out that having the Soft Starters was not going to change the vacuum pump priming issue, he was relieved to hear that. If I can find the videos and post them to YouTube or something, I’ll add a link.