60 Hz device to 50 Hz Source

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Hameedulla-Ekhlas

Hameedulla-Ekhlas

Senior Member
Location
AFG
Greeting all,
I have two incinerator machines in a project which have the below electrical data.

Voltage = 120 volt
Phase = 1 ph
Herts = 60 Hz

I have provided with genertor 120 volt,1ph,60z which is operating now.

Now we need to provide one more additional connection from city power but city power has the below electrical data

voltage = 220volt 1ph, 380 volt 3ph
Hertz = 50 Hz


What device should I use to connect the incinerator machines to city power?
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
100220-1439 EST

What is an incinerator machine? Is this a big resistor and/or does it include induction motors and/or relays and/or transformers. Resistor no problem with 50 Hz, all magnetic devices may have a problem with 50 Hz.

If it is only a resistor, then you simply might use a half-wave diode rectifier to reduce the voltage. Other wise an SCR phase shift controller would work. A half-wave diode causes DC current in the source as well.

If you reduced voltage from 120 to 100 because of the 50/60 frequency ratio and the devices still worked, then the system might work. Motor power output would be less. You would be nearer dropout on relays.

Any devices in the system rated for 50-60 Hz use could be run at full normal voltage.

Potentially you have a problem.

.
 
Hameedulla-Ekhlas

Hameedulla-Ekhlas

Senior Member
Location
AFG
incinerator machine is a machine which burns garbage. All garbage are collected and brought to these machine. These machine only burns waste garbage. It contains motor ofcourse.

Can any one give some explaination regarding to the above information.
 
S'mise

S'mise

Senior Member
Location
Michigan
No Biggie

No Biggie

I would just get a 2:1 transformer to knock down the 220v to 110v.
Yes, motors will run slightly slower on 50hz but it should be fine provided their is not any sensitive electronic equiptment. (It throws off clock speed in some electronics)

Make sure the voltage does not dip below 110 after start up, and monitor temps with an IR thermonitor to be safe.

If you need to, you can use a buck/boot transformer to keep voltage where you need it.

Good luck
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
100220-2136 EST

S'mise:

When you have a ferromagnetic material and a coil coupled to that core and you apply an AC voltage excitation to the coil you cycle the magnetic flux + and - each cycle. The integral over time of the excitation voltage determines the maximum flux density in the core material. The more slowly this voltages builds up the greater the integral and the more you increase the flux density before it reverses. This flux lags the voltage and reaches its maximum at a voltage zero crossing. Saturation of a magnetic material is a function of the flux density and prior history.

If you maintain the same voltage level and lower the frequency of excitation, then you force the core more into saturation increasing the magnetizing current and therefore heating of the coil. If a electromagnetic device has been designed for 60 Hz operation, then roughly speaking you should not apply a voltage greater than 50/60 of that voltage at 50 Hz.

Some devices will be designed to work at 50 Hz at a given voltage level and given a 50-60 Hz rating at that voltage by some other design modifications that reduce the losses as frequency is increased. One of these is lamination thickness to minimize eddy current losses.

.
 
S'mise

S'mise

Senior Member
Location
Michigan
Your right but...

Your right but...

gar said:
100220-2136 EST

S'mise:

When you have a ferromagnetic material and a coil coupled to that core and you apply an AC voltage excitation to the coil you cycle the magnetic flux + and - each cycle. The integral over time of the excitation voltage determines the maximum flux density in the core material. The more slowly this voltages builds up the greater the integral and the more you increase the flux density before it reverses. This flux lags the voltage and reaches its maximum at a voltage zero crossing. Saturation of a magnetic material is a function of the flux density and prior history.

If you maintain the same voltage level and lower the frequency of excitation, then you force the core more into saturation increasing the magnetizing current and therefore heating of the coil. If a electromagnetic device has been designed for 60 Hz operation, then roughly speaking you should not apply a voltage greater than 50/60 of that voltage at 50 Hz.

Some devices will be designed to work at 50 Hz at a given voltage level and given a 50-60 Hz rating at that voltage by some other design modifications that reduce the losses as frequency is increased. One of these is lamination thickness to minimize eddy current losses.

.
Click to expand...

Thanks Gar, That makes sense that 50hz design devices will run slightly hotter. I agree technically, but on a practical side most devices (relays/contactors) have a duel 50/60hz rating. Even if not, will work fine on 50hz. Yes, the life of the device will be slightly shortened because of heat. The major thing is the motors will run slower.
Using precaution is always the best policy. After some investigation into the machine components he may decide 50hz is fine.

I have ran machines on 50hz in the past and have not seen any long term problems.
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
100221-1316 EST

S'mise:

True that many devices are designed for 50-60 Hz operation, but you need to know if that is the case.

A device that was designed for 60 Hz operation, such as the motor on my drill press, may not have good life at 50 Hz. This would because the device was never designed for 50 Hz. It is all about where you are on the hysteresis curve and how sharp is that curve.

Some data from my cheap import drill press. This is almost no load data because I do not have a convenient way to put a controlled load on it. The load is only belt, spindle bearings, and windage.

Nameplate 1/2 Hp 115 V 9 A

Kill-A-Watt measurement (not a highly accurate instrument, but useful)
100 V 4.76 A 306 W
116 V 5.41 A 316 W
140 V 7.62 A 420 W

The ratios for 100 to 116 are
Voltage ratio is 1.16
Wattage ratio 1.03
Current ratio 1.14

The ratios for 116 to 140 are
Voltage ratio is 1.2
Wattage ratio 1.33
Current ratio 1.41


A 175 VA Signal Transformer Co. transformer does much better in this voltage range than the import motor.

.
 
S'mise

S'mise

Senior Member
Location
Michigan
Yes Gar, I follow your example and agree with you entirely. There is always a down side with ignoring tollerances, Some times minimal, some times catostrophic.

Like I said, some investigation into the actual components used is crutial before deciding something like runing on a different frequency.

Hameedulla was talking about a incinerator machine which I envision as a Gas fired machine with a few electrical components such as a blower motor, conveyor moror and maybe a few relays? I don't know. But like I said, I have ran 60hz on 50hz and the other way around and had no long term problems. Ultimately it is up to Hameedulla to decide exactly what he is hooking up and the internal ratings.

By the way, Hameedulla, can we just call you Ham or Hammy? :grin:
 
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