10 hp Century Repulsion Start - Induction Single Phase Motor

Manufactured in U.S.A. by
CENTURY ELECTRIC CO.
St. Louis, MO.
Type RS Frame RS19 H.P. 10
Volts 110 or 220 Amp. 96 - 48
Cycles 60 R.P.M. 1750
Serial No. 786934 Spec. No. (none)
Continuous Open Rating Temperature
Rise Not More Than 40' Centigrade
Patented Dec. 29, 1914, Oct. 19, 1915.

In this video the motor is connected for 220 volts and is supplied with around 90 volts from a Variac, such that I can simply plug it in and enjoy it without having to connect it to a 240 volt socket. It will actually accelerate and run on a 15 ampere power strip without tripping it's breaker. I have run it on 240 volts, and when first thrown across the line you can feel it in the concrete floor. Once up to speed, the magnetic song it sings is also very nice on full voltage, though it makes a similar sound as heard in this video just from the slots in the iron passing one another- the magnetic sound on full voltage is just louder.

The motor next to it is a 1/4 hp, of the same make, type and vintage. It even sounds the same, but MUCH quieter.

This is just what the motor looked like when I acquired it around a year ago. It appears to be totally original, inside and out, other than it's paint. As far as I know, they were all supplied eggshell black.

In it's most recent former life it was driving a ten hp Kellogg American two cylinder, two stage air compressor, which I also have. This set up was used in an auto paint shop, supplying several painters and other air tools. The fellow I bought it from had had it for at least 30 years, and did not know what it's former service was. Forever lost to history, I guess.

It's governor was sticky such that it would accelerate to greater than synchronous speed before transitioning to induction- at which point the lights in the shop would flash bright as it almost instantly dynamic braked back down to synchronous speed- pretty scary to hear it going too fast! In reality it was probably only going a couple hundred rpm at most overspeed. Yes, a repulsion motor can exceed synchronous speed- their characteristics are practically the same as those of a series motor. So I disassembled, cleaned, lubricated and adjusted it to have it run the way you see it here.

My camera's microphone does not do it's music justice at all- it seems to mostly pick up the sound of the fan. The fan is fairly loud, but it's music is also quite loud. I guess the mic prefers the rushing air noise.

Category:

Science & Technology

Tags:

• century
• repulsion
• start
• induction
• single
• phase
• electric
• motor

[Beitz57]

I seen one and the guy was running it with 110 volts.

Will your work with 110 ?

[realvanman]

@Beitz57 Hi, yes it can be wired for 110 volts- full load amps are 96 at 110 volts!

[mainelyelectric]

dam that has good bearings what is it from? Please reply

Thanks Ben

[realvanman]

Hi Ben, I wish I knew, but I'm not sure what the motor's original service was. The fellow I bought if from had it powering a large Kellogg American compressor from the 60's. Many years ago he used this compressor at a body shop, and reportedly it supplied air to several painters at once. I thoroughly cleaned the bearings and their oil sumps while I had the motor apart, and the shaft and the bearings are in excellent shape. I filled the sumps with a very light, synthetic motor oil.

[johntdso]

Would like to actually hear this motor run on full voltage. One thing about repulsion start motors, the inrush amperage is much lower than a comparable capacitor start motor and can be reduced even further with a corresponding loss of starting torque by moving the brushes toward (soft neutral).

The largest repulsion start motor I saw was a 7-1/2 Hp Century on a crematory furnace blower. The speed of this motor was 850 RPM, 8 poles.

[realvanman]

@johntdso Hi, the next time I get a chance I'll make a video of it starting and running at rated voltage. I have a couple of 6 pole Centurys, but have never seen an 8 pole! That's really neat!

[gjtoiw]

That motor will last forever !!

[HmongGuitarPlayer]

@realvanman 8 pole runs at 900 rpm.it's pretty slow to be a blower motor.with slipage.

[Bigrick356]

Great vid! I have the exact same motor. Its a 5 hp tho yet shares the same RS19 sized frame. Heavy one! Century motors are cool

[realvanman1]

@Myers169 Hi, no, the little motor is a 1/4 hp, and is only there for size reference. The 10 hp is single phase.

[Myers169]

Now THAT is a great video!! Thanks for posting.

Question: Is the purpose of the little motor to create 3 phase for the Century?

[steamwally]

Very, very nice. I have come accross a few of these and it's allways facinating watching them start!

[Bigrick356]

How much does this one weigh? Im guessing with all the cast iron and copper its gotta easily tip 1000 lbs

[speedstick77]

Ya skeered me when it started up. Gotta check my Fruit of the Looms.

[Bigrick356]

LOUD MOTOR

[chuckbear1961]

SO YOU WANT TO SELL IT!!!!!!!!!!!!!!!!!!!!!!!!