220 delta required from 480 not sure if 480 is wye or delta for transformer

[Fordean]

Need a 480 (wye or delta) to 220 delta

what type of 75kva tranformer should i purchase howdo i tell if i have 480 wye or 480 delta
800 amp 480v is present

 

[Dsg319]

My opinion, doesn’t matter if 480 Wye is present or not.

Don’t need the primary neutral at the transformer. Just get a Delta primary/Delta secondary transformer.

Most generally customer owned transformers I have seen are typically primary Delta wound even if it’s a 480/277 wye service. Just no need for the neutral on the primary.

 

[kwired]

Need a 480 (wye or delta) to 220 delta

what type of 75kva tranformer should i purchase howdo i tell if i have 480 wye or 480 delta
800 amp 480v is present

Your transformer won't care if the source is wye or delta derived, it only will want to see 480 volts between each input lead.

 

[winnie]

Agreed on the above: your transformer doesn't care if the 480V source is wye or delta, grounded or ungrounded. You simply get a transformer with a 480V _delta_ primary.

The question you need to spend more time noodling on is what your secondary should be.

'220V' is a confusing name for a supply; it was commonly used in the past but...standard usage voltages are 240V and 208V, and when someone says '220V' you don't really know what they mean.

If you need lots of 120V for things such as an office, then you want a 208/120V wye secondary.

If you need 240V three phase for old machinery then you probably want a 240V/120V delta secondary (which gives you a small amount of 120V capacity for incidental 120V loads).

If you need 240V for VSD fed low voltage motors then you may want to consider a 240V/139V wye secondary. The 139V is useless, but the balanced L-N loading is a benefit for drives because of input transient voltage protection.

If you specifically need 240V _single phase_ (say an application using lots of residential cooking equipment) then you might want to look at a single phase transformer.

Finally if you have lots of true 240V three phase loading you may want to look at how easily it could be converted to 480V operation. Many things such as motors are dual voltage, and the lower current at 480V can make the installation significantly cheaper.

-Jon
Do you need a true 240V secondary

 

[kwired]

Agreed on the above: your transformer doesn't care if the 480V source is wye or delta, grounded or ungrounded. You simply get a transformer with a 480V _delta_ primary.

The question you need to spend more time noodling on is what your secondary should be.

'220V' is a confusing name for a supply; it was commonly used in the past but...standard usage voltages are 240V and 208V, and when someone says '220V' you don't really know what they mean.

If you need lots of 120V for things such as an office, then you want a 208/120V wye secondary.

If you need 240V three phase for old machinery then you probably want a 240V/120V delta secondary (which gives you a small amount of 120V capacity for incidental 120V loads).

If you need 240V for VSD fed low voltage motors then you may want to consider a 240V/139V wye secondary. The 139V is useless, but the balanced L-N loading is a benefit for drives because of input transient voltage protection.

If you specifically need 240V _single phase_ (say an application using lots of residential cooking equipment) then you might want to look at a single phase transformer.

Finally if you have lots of true 240V three phase loading you may want to look at how easily it could be converted to 480V operation. Many things such as motors are dual voltage, and the lower current at 480V can make the installation significantly cheaper.

-Jon
Do you need a true 240V secondary

This becomes more significant if you have motors over 15 to 20 HP. Though if you only have a single larger motor sometimes it still ok to supply it with 208 or 240 instead of 480 volts, especially if the remainder of load is 120 or 208-240 single phase loads.

 

[Fordean]

Agreed on the above: your transformer doesn't care if the 480V source is wye or delta, grounded or ungrounded. You simply get a transformer with a 480V _delta_ primary.

The question you need to spend more time noodling on is what your secondary should be.

'220V' is a confusing name for a supply; it was commonly used in the past but...standard usage voltages are 240V and 208V, and when someone says '220V' you don't really know what they mean.

If you need lots of 120V for things such as an office, then you want a 208/120V wye secondary.

If you need 240V three phase for old machinery then you probably want a 240V/120V delta secondary (which gives you a small amount of 120V capacity for incidental 120V loads).

If you need 240V for VSD fed low voltage motors then you may want to consider a 240V/139V wye secondary. The 139V is useless, but the balanced L-N loading is a benefit for drives because of input transient voltage protection.

If you specifically need 240V _single phase_ (say an application using lots of residential cooking equipment) then you might want to look at a single phase transformer.

Finally if you have lots of true 240V three phase loading you may want to look at how easily it could be converted to 480V operation. Many things such as motors are dual voltage, and the lower current at 480V can make the installation significantly cheaper.

-Jon
Do you need a true 240V secondary

I have attached the picture of the machinery, Its from Japan, Wired for USA supposdly, 220 Delta
I have a 480 delta to 208 wye transformer quoted. 75KVA, I will fuse disconnect at 150 amp LPJ. And a small sub panel next to it.
I also have to feed a 30 amp 3ph 208 volt compressor.

Is the 208 volt secondary ok for this machinery. 208 wye type? I dont know if the 480 is wye ok on this setup.

Largest motor is 220vDelta/380vwye 60 hz 18.5 Kw 62/36 A 92.4 Eff%
Also, Motor control center that came with unit. Has no label showing what power requirements. I opened all motors and add up amps.
Looked at gauge of wire going to main switch. And put this together. Guys from Japan wont communicate. Except to say its 220v, I opened all motors and it is wired 220v.

 

[drcampbell]

I have attached the picture of the machinery, Its from Japan, Wired for USA supposedly, 220 Delta ...

Only the first page of your attachment showed up, and there's no useful information there.

I don't have a lot of confidence in what they're telling you. 220 hasn't been popular in the United States since I was a zygote.
Electric power in Japan is a mishmash of systems. Part of the country is 50 Hz, part 60. Part of it was wired with European equipment & expectations, part American. Even if they were communicating openly, I would want any Japanese supplier to be very specific.

If there aren't any 110-volt loads, or there's no noodle conductor, it doesn't matter how the transformer secondary is configured.
If this is the only thing that will be connected to this forthcoming transformer, you can select voltage taps to achieve the right voltage -- but that requires somehow figuring out what the "right" voltage is.

... Is the 208 volt secondary ok for this machinery? ...

Nobody really knows until you have a frank & open dialogue with a knowledgeable application engineer. If the motors are marked "220/380", not "208-220/380", that would suggest not. And what about every other component in the box?

If it does get hooked up to 208, it's very possible that it will "work" the first time it's powered up and for a short time thereafter, but not be very reliable.

 

[petersonra]

I'd be inclined to get a 480 to 220 delta xfmr. They are not hard to come by. Just get a 480 to 240 unit with some 2.5% taps. I would not be using 208 V. Just get what the machine wants.

Incidentally, the reason they don't want to communicate with you is because most of the money on these kind of machines is in spare parts and service. No reason to give anything away. Unfortunately, the owner bought a bit of a pig in a poke. He pretty much deserves the bad and expensive things that will happen to him for doing so. he should have consulted someone competent before buying it.

 

[paulengr]

IEC specifies +/-10% voltage for motors but realistically +/-5% is better. 208 is 5.6% low so just make sure you don’t have much drop. Realistically though you should have taps at 2.5 and 5% on the transformer so if you tap it all the way up you will have 219 V if the input is close to rated.

220 is annoying because it’s not really a standard, not on the IEEE/ANSI list except as a secondary standard.

 

[synchro]

Under the heading Technical Data, at the link below it says:
Power: 4P, 380/220V, 50/60Hz
So I assume that means 4-wire wye 380V L-L and 220V L-N, which is quite common internationally but at 50 Hz.
Since this appears to be from a vendor of the product, I would try to confirm with the manufacturer at that it's suitable for use at 60Hz.
They have contact info at: http://www.silverengineer.com/plus/list.php?tid=8

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silverengineer.en.made-in-china.com

This mentions it has a Mitsubishi inverter with a 15 kW Siemens main motor:

阿里云万网虚机手工关停页面

www.silverengineer.com

This is an example of the type of transformer that would be suitable, assuming that the requirements above are valid:

3-Phase 480V Delta - 380 Y 220

This transformer is designed to convert 3-phase 480v to 3-phase 380 Y 220 to run equipment such as panels, motors, CNC machines, welders, conveyor systems, pumps, printing equipment, fabrication tools, cryptocurrency miners, datacenter equipment, and other business machines. Primary Voltage: 480...

store.maddoxtransformer.com

 

[winnie]

Under the heading Technical Data, at the link below it says:
Power: 4P, 380/220V, 50/60Hz
So I assume that means 4-wire wye 380V L-L and 220V L-N, which is quite common internationally but at 50 Hz.
Since this appears to be from a vendor of the product, I would try to confirm with the manufacturer at that it's suitable for use at 60Hz.

This!

The unit is not designed for 220V. It is designed for 380/220V, which as synchro says means 380V wye 3 phase power.

The sort of transformer that he suggests is the simplest approach. I would confirm with the manufacturer that the unit is suitable for use at 60Hz, however if the main motor is controlled by an inverter than this is very likely the case.

-Jon

 

[Fordean]

Going with 480 to 240 trans Tapping 500v tap to bring voltage 228v Only way i can figure

 

[winnie]

Going with 480 to 240 trans Tapping 500v tap to bring voltage 228v Only way i can figure

I really believe you are reading the spec for the unit wrong. I believe you need 380V, not 220V. (In particular you need 380/220V wye, where the 380V is the L-L voltage and 220V is the L-N voltage, just as synchro described)

-Jon

 

[Fordean]

I really believe you are reading the spec for the unit wrong. I believe you need 380V, not 220V. (In particular you need 380/220V wye, where the 380V is the L-L voltage and 220V is the L-N voltage, just as synchro described)

-Jon

Now im wundering

 

[Fordean]

I really believe you are reading the spec for the unit wrong. I believe you need 380V, not 220V. (In particular you need 380/220V wye, where the 380V is the L-L voltage and 220V is the L-N voltage, just as synchro described)

-Jon

I do see references 380/220 But i checked motors They have 380/220 380 high 220low
They all tapped for low?

 

[Fordean]

I'd be inclined to get a 480 to 220 delta xfmr. They are not hard to come by. Just get a 480 to 240 unit with some 2.5% taps. I would not be using 208 V. Just get what the machine wants.

Incidentally, the reason they don't want to communicate with you is because most of the money on these kind of machines is in spare parts and service. No reason to give anything away. Unfortunately, the owner bought a bit of a pig in a poke. He pretty much deserves the bad and expensive things that will happen to him for doing so. he should have consulted someone competent before buying it.

Went for 480-240 Mgm tech says use 505 tap will bring me to 228v Close enough i think

 

[petersonra]

I do see references 380/220 But i checked motors They have 380/220 380 high 220low
They all tapped for low?

Most IEC style 3 phase motors can be wired either delta (220 V) or wye (380 V). Depending on how they are wired determines what voltage they need. If you checked and found they are wired for 220 V, they need 220 V.

 

[Fordean]

Most IEC style 3 phase motors can be wired either delta (220 V) or wye (380 V). Depending on how they are wired determines what voltage they need. If you checked and found they are wired for 220 V, they need 220 V.

View attachment 2556773

 

[MTW]

I have wired several pieces of machinery over the years manufactured in Japan. Large 5 color printing presses, 40' long 100HP spindle milling machines. They all came configured for 3Φ 220V 60Hz operation. Each building had a different service configuration, it is important to measure the actual service voltage before selecting the the transformer.

When the equipment contains VFD's or servo drives and computer controls, you really need a grounded wye output on whatever transformer you select. It's not because you need a neutral. Its because you need a ground that is symmetrical with all three legs for equipment functionality and reliability. Most of the rest of the world only uses wye systems and takes that part for granted. So when they say 220 delta, it usually means they don't really know what a delta is, they have no experience with deltas in their homeland.

Here a delta output has no way to be symmetrically grounded, you either can do a center tapped delta grounding , a corner grounding, or ungrounded with a ground fault monitor. None of these choices are any good for equipment reliability with drives and electronic components. Corner grounding can be downright destructive as soon as you power it up.

Using a delta output coil and leaving it ungrounded, is against the NEC and leaves you with liability down the road, but can function, for a while. I recently disconnected a 600V Canadian paper shear that had been connected for years to an ungrounded delta coil, but it had no drives or electronics.

The way I handle these is to specify a delta input/ wye output transformer that has enough taps to adjust the output to very near the 220V requirement. This is why you need to know the actual site service voltage, and it can vary widely during the day depending on the local grid robustness and neighboring businesses that have heavy loading during certain times of the day.

In your case of 480V input and 220V output, I would select a 480V delta input and a 208V wye output that has enough taps to get the output voltage very near to your required 220V. Tap adjustments are normally only available on the input side. So to raise the output coil voltage, you need to use a lower primary tap voltage. Higher voltage in, (adjusting the input taps to a lower voltage than actual), means higher voltage out. This will drive the transformer closer to saturation. but a 5% adjustment shouldn’t be a problem.

Be sure to properly bond the output XO terminal to the building and transformer and run a EGC to the machine grounding terminal. On the compressor I would look for another source other than the 220V output, unless the manufacturer will approve of the higher voltage input.

 

[petersonra]

I have wired several pieces of machinery over the years manufactured in Japan. Large 5 color printing presses, 40' long 100HP spindle milling machines. They all came configured for 3Φ 220V 60Hz operation. Each building had a different service configuration, it is important to measure the actual service voltage before selecting the the transformer.

When the equipment contains VFD's or servo drives and computer controls, you really need a grounded wye output on whatever transformer you select. It's not because you need a neutral. Its because you need a ground that is symmetrical with all three legs for equipment functionality and reliability. Most of the rest of the world only uses wye systems and takes that part for granted. So when they say 220 delta, it usually means they don't really know what a delta is, they have no experience with deltas in their homeland.

Here a delta output has no way to be symmetrically grounded, you either can do a center tapped delta grounding , a corner grounding, or ungrounded with a ground fault monitor. None of these choices are any good for equipment reliability with drives and electronic components. Corner grounding can be downright destructive as soon as you power it up.

Using a delta output coil and leaving it ungrounded, is against the NEC and leaves you with liability down the road, but can function, for a while. I recently disconnected a 600V Canadian paper shear that had been connected for years to an ungrounded delta coil, but it had no drives or electronics.

The way I handle these is to specify a delta input/ wye output transformer that has enough taps to adjust the output to very near the 220V requirement. This is why you need to know the actual site service voltage, and it can vary widely during the day depending on the local grid robustness and neighboring businesses that have heavy loading during certain times of the day.

In your case of 480V input and 220V output, I would select a 480V delta input and a 208V wye output that has enough taps to get the output voltage very near to your required 220V. Tap adjustments are normally only available on the input side. So to raise the output coil voltage, you need to use a lower primary tap voltage. Higher voltage in, (adjusting the input taps to a lower voltage than actual), means higher voltage out. This will drive the transformer closer to saturation. but a 5% adjustment shouldn’t be a problem.

Be sure to properly bond the output XO terminal to the building and transformer and run a EGC to the machine grounding terminal. On the compressor I would look for another source other than the 220V output, unless the manufacturer will approve of the higher voltage input.

regardless of what the output of the transformer is, the motors appear to be able to be wired in either star (wye) or delta configuration. The motors don't care any if the supply is delta or wye. The drives by default usually expect a wye source, but can often be configured for ungrounded delta systems without too much trouble. Corner grounded delta or high leg delta is not something you want to put drives on in most cases.