motor question

[plunger]

I bought a couple of motors at an auction.One of the motors is a 5 hp motor but I notice the name plate says it is 60hz I am electrically challenged In my country we have 240v at 50hz. Will this motor run ? Or am I going to blow it up?I also bought this other motor that looks like a reduction gearbox of sorts with a built in handle .In homeshop fashion does anyone have a suggestion as to how the orange motor could be usefull Regards Eugene

[ftl]

If the voltage rating for the motor is 220 or 240 V it will probably be fine. It will turn a bit slower (50/60 * the nameplate speed). It may not produce full power, but should come close.

[darryl]

You'll just have to try it. Some motors will work ok on the lower frequency while others will overheat. You can almost always run a 50 hz motor on 60 hz though. Voltage rating has to be right- you can't run a 110v motor on 220 without cooking something. Sometimes you'll have a problem with a 220 motor if your voltage is unusually high, like 260 or something.

[plunger]

motor question no 2

The motor is rated at 230v and we work on 240 v here in s africa

[lakeside53]

One of the USA standard mains voltage is also 480/240 volts, but the motor are often rated at 460/230 to account for wiring losses. The motor will work fine on your system

[The Artful Bodger]

Hi Plunger, I am sure the motor will be fine but avoid stalling it as it may be more vulnerable to damage in that situation on a lower mains frequency.


The orange motor it totally useless, please send it to me for safe disposal!

[lakeside53]

I don't believe its more likely to stall or be damaged on 50hz. If anything, the locked rotor curent will be lower on 50hz than 60hz.

The start capacitor (that dented round structure on top) will probably work fine as is, but if the startup seems labored, increase the capacitance about 20%

The orange motor: looks like someone put a handle on it to give accurate positioning downstream, or, a cheap hand-powered reduction gearbox for something. Might want to take the handle off before applying power

[Evan]

The orange motor looks like it might make a nice wet and dry grinder. Dry on the high speed end and a wet wheel on the slow end. They sell grinders with a similar configuration and since that motor is sealed it would work well in the service.

[plunger]

Evan I quickly googled a wet and dry grinder and most stuff that came up referred to kitchen stuff. Somehow I have a feeling you have a different idea for this. What is a wet and dry grinder useful for in a homeshop

[The Artful Bodger]

. If anything, the locked rotor curent will be lower on 50hz than 60hz.

Can you explain this please as I assumed the impedance would be lower with the lower mains frequency? Thanks.

[plunger]

I hate being so dumb with motors. I am feeling that my auction day is going to work out to be a flop. I took the motor apart as I could see a wasps nest in it. The motor looks hardly used.I then fired it up by holding the wires on the lugs This immediately burned up the wires in my hand as it arced the lug off. I then did a more permanent connection and it tripped the house.Then I took the two covers off where the capacitors are. The capacitors have been stolen.I then tried to spin it by hand and it seemed to start for a short while and then tripped the house. Could someone explain what these capacitors do and what type of caps are they. If I had to spin it by hand should it not work without caps. Is it still possible that if I put caps in it might work or does it sound like the magic smoke has escaped? How would I know what type and size of cap this takes.Do you think 5 hp draws to much start up current and so trips the house. Its on a 20 amp circuit breaker.Or is this the function of the caps. This is a motor made by emmerson in the states and is rated for 230volts. Is your power different. It also has 1 phase written on the info plate Here in s africa our power is single phase 240volt We have a live a neutral and a earth. Why in the states do they talk about dual phase. I am getting confused.

[garagemark]

You will definitely need the caps. They act as a kind of "booster" to either get things going or to keep things going (start or run, or sometimes both).

As I do not really understand your power system, you say you have a hot wire with 230 volts, a neutral, and earth ground? If so, then your motor probably won't work. 230 volt single phase in a motor is usually two 120 volt hot wires, with no neutral used (only use an earth ground to the motor case for safety). So if you are hooking up to an actual "neutral" (which is essentially a ground), you are shorting the motor out, which in turn is tripping your house mains.

By the way, I like the little orange motor, I could see all kinds of uses for it. The wet/ dry grinder could be a good choice if the geared side isn't too fast.

[DENedbalek]

I hate being so dumb with motors. I am feeling that my auction day is going to work out to be a flop. I took the motor apart as I could see a wasps nest in it. The motor looks hardly used.I then fired it up by holding the wires on the lugs This immediately burned up the wires in my hand as it arced the lug off. I then did a more permanent connection and it tripped the house.Then I took the two covers off where the capacitors are. The capacitors have been stolen.I then tried to spin it by hand and it seemed to start for a short while and then tripped the house. Could someone explain what these capacitors do and what type of caps are they. If I had to spin it by hand should it not work without caps. Is it still possible that if I put caps in it might work or does it sound like the magic smoke has escaped? How would I know what type and size of cap this takes.Do you think 5 hp draws to much start up current and so trips the house. Its on a 20 amp circuit breaker.Or is this the function of the caps. This is a motor made by emmerson in the states and is rated for 230volts. Is your power different. It also has 1 phase written on the info plate Here in s africa our power is single phase 240volt We have a live a neutral and a earth. Why in the states do they talk about dual phase. I am getting confused.

Trying to spin it by hand and having it try to run sounds to me like you may have a good motor. Based on what you've said about it so far, I suspect that you have a start capacitor style motor. The wasp nest needs to come out of there, just clean it out without damaging the laquer on the windings. If necessary, take the end bell off of the motor and wash the dirt & mud out of it. Let it dry completely before reassembly. With a start capacitor, you may have a mechanism on the shaft (centrifugal switch) to drop the start winding circuit out after the motor comes up to speed. Be careful to not damage it when disassembling the motor.

The 240 v / 50 Hz should work just fine with that motor. On most motors designed for 240v here in the US, you assume the line voltage is comprised of two 120v lines 180 degrees apart (meaning that you get a voltage measurement of 240v between the two lines). What you have is 240v on line 1 and 0v on the other line. The motor does not care how it gets the 240v across the windings.

If you do a search for the model number of the motor you may be able to find the mfr wiring diagrams and parts information. Key here is to get the correct capacitor for it. I have some reference materials I can dig through if you can put a decent picture of the nameplate in a post here (or send me a PM).

Dwayne

[J Tiers]

if there are two capacitors, one will be for starting only, and the one stays in-circuit for running.

You need both.

I suggest posting a good clear picture of the nameplate. That usually has quite a good amount of info that you need.

There is no guarantee that the motor is good, of course, but also no guarantee that it is wired correctly. There are several wiring errors that can cause exactly what you see. And of course not having the start and run capacitors will be an issue.

Even when correctly wired and with all good parts, a 5 HP motor can easily draw 7 or 8 amps with no load. The starting current will be maybe 5 to 6 times that much (or more at 50 Hz) and is findable from the nameplate data. The motor could easily have been drawing somewhere above 40 amps in the condition you tested.

There is a chance that the motor will not work well on 50 Hz, but we don't know that yet. Nameplate data will help determine that. Since it is there in SA, and it apparently seems to have been used, but does not smell burnt up, it probably works on your current.

Naturally if you run it with a VFD, everything will be perfectly fine regardless. I assume you don't plan to.

[lakeside53]

Can you explain this please as I assumed the impedance would be lower with the lower mains frequency? Thanks.

No I can't explain. It was late and I got it backwards. That's what happens when you spend 1/2 of your life in 50 hz countries, and a lot of time where they use both! Sad.. I actually get paid for similar advise. lol... (note to self - don't post if you've had a few).


Plunger : yes, your 20amp breaker is insufficient to run a 5hp motor starting as you did - the surge from the few rpm to it's slip/synchonous speed will be too much. You can get over much of this by bolting it to a bench and using another motor to spin it up to near the correct speed, then cut power to the drive motor and apply to the 5hp. Similar to a pony motor on and RPC. Even then, a 30-40 amp breaker would be better.

As others have requested - post a pic of the motor plate.