Three phase Wye Connection

[Jesilka]

Thank God, I found your site. My company ships products directly from the OEM in Turkey to other countries. We recently shipped two AUTOCLAVES to Saudi that were labeled 220/230 Volts 50/60 Hz Three Phase. Upon receipt of the units the customer found out that the line to line voltage is 400 volts and line to neutral is 230. Saudi does not provide 220 three phase as my cusotmer stated that the power available is 230/3/60Hz: meaning line to line is 230 and line to neutral 132.

The question is what is the correct way to label a machine?
1) 220/230 Volts 50/60 Hz Three Phase. (should the customer know that they need to multiply by 1.732 to get the line to line voltage? What is the customer to assume if he sees only the above label?
2) should the OEM have labeled the unit simply as 400V three phase?
3) should it be 400Y and state that it is phase to phase or 230 Line to neutral?
You help will be extremely appreciated,
Jesilka

 

[charlie b]

Re: Three phase Wye Connection

In the US, at least, when you state that a power source or a piece of equipment is three phase, and when you give a voltage level, it will be understood that the voltage is a phase to phase measurement. So I understood that your "220/230 volt 50/60 hertz three phase" would operate sucessfully on either 220 volt phase to phase or 230 volts phase to phase, and that it could operate at either 50 hertz or 60 hertz.

I would expect that your operations manual (or owners manual or whatever you send with the equipment) would tell the user what steps, if any, must be taken with the different power sources. For example, if they need to connect the wires differently for 220 colts versus 230 volts, then your instructions should tell them what to do.

 

[LarryFine]

Re: Three phase Wye Connection

Originally posted by Jesilka:
. . . labeled 220/230 Volts 50/60 Hz Three Phase.

Originally posted by charlie b:
. . . your "220/230 volt 50/60 hertz three phase" would operate sucessfully on either 220 volt phase to phase or 230 volts phase to phase, and that it could operate at either 50 hertz or 60 hertz.

I took the rating with a slight twist: 220v @ 50 Hz or 230 @ 60 Hz, not either either @ either.

But then, I'm just that kinda guy.

 

[DaveTap]

Re: Three phase Wye Connection

Charlie is correct and I know it is the same for Japan, Germany, Switzerland, Taiwan, and Australia, but I'm a little confused. Is the customer's voltage 400V or is your machine 400V line to line? You should not need to multiply by 1.732 to get the line voltage. It should have been stated on the nameplate... in this case it says 220V-230V line to line so the customer only has 400V availible? I know there are no standards for power in Saudi but are you sure it is not 380V/3 phase/60hz which is more common there?
Is the voltage to neutral actually used in your equipment? (like for the control system or auxillary outlets?)
In the case of a large auto-clave you will have several systems to worry about: 1 controls, 2 pump or compressor motors, and 3 the heating circuits. Depending on your system they may use the same voltages or may all require different voltages. Once you have all the information I would recommend also finding acceptable tolerance ranges and setting them up on a web page so your customers (and their electricians) can determine and plan their installtion beforehand instead of finding out after the equipment has been delivered that it won't work or they have run the wrong wires. Having worked for a Swiss, a German, 2 Japanese, and several American equipment manufacturers I've seen many different approaches to this issue. European machines typically are designed for 380V/50hz and some required large transformers to adjust the voltage and/or replacement of pump motors, thermal overloads and circuit breakers in the controls. Heating equipment can typically be wired series or parallel allowing use of dual voltages with the proper wire or circuit breaker changes. Of course all this would require some re-engineering by your manufacturer. Since we did all the installations it was our job to check the customer's voltage and power to select proper transformers etc. In Saudi it can differ from one side town to the other... good luck

 

[jim dungar]

Re: Three phase Wye Connection

380Y/220V was the common European voltage.
400Y/230V is now their preferred voltage.

This is similar to what happened (440 increasing to 480V)in the US during the 50-60's. So now the Europeans will have the same situation of motors being rated 380V being used on a higher nominal supply voltage.

 

[Jesilka]

Re: Three phase Wye Connection

The name plate of the Autoclave only says: 220/230 Volts - 50/60Hz Three phase. According to the manufacturer in a Y connection system the above is the same as 380/400 Volts 50/60 Hz three phase, because of the Y connection. The machine needs 380/400volts three phase in order to run. This voltage is not available at the customer site. His available voltage is 230volts/60Hz three phase.

The manufacturer never stated that this is Y connection. Therefore, the customer in Saudi thought 230 three phase was a phase to phase measurement because his line to neutral is 132x1.732. It seems that the government hospital will not accept a higher than 132 Y connection because of safety reasons since it is not in an industrilized area. (By the way isn't this the same as in the US?) In any case the total voltage that they can get is 230volts 60Hz three phase as explained above from the 132 line to neutral idea.

I only know the basics about electricity but it seems to me that this unit was not properly labeled . "220/230volts 50/60Hz three phase" does not tell the customer that this is a Y connection and neither that it requires 380/400 volts three phase to run. Don't you think? I cannot expect my customer un the machine. Your comments are highly appreciated.

 

[charlie b]

Re: Three phase Wye Connection

Originally posted by Jesilka: The name plate of the Autoclave only says: 220/230 Volts - 50/60Hz Three phase. According to the manufacturer in a Y connection system the above is the same as 380/400 Volts 50/60 Hz three phase, because of the Y connection.

That is not the usual (i.e., conventional) way to convey voltage information. When it comes to voltage ratings, it does not matter how the machine is wired internally (i.e., WYE versus Delta). If you tell me it is 230 volts, 60 hertz, 3-phase, then I will infer that it needs 230 volts phase-to-phase. If the manufacturer intends otherwise, then it is up to the manufacturer to state the voltage rating correctly.

The difference between WYE and Delta has to do with whether it needs a neutral wire. If it does, then it is common to give the voltage rating in terms of both its phase-to-phase voltage and its phase-to-neutral voltage. That could be 230/132 volts, or it could be 400/230 volts, but it could not be expressed as just 230 or as just 400. So if the manufacturer wants 400 volts phase-to-phase and if they also want a neutral (i.e., for a WYS connection), then the product should have been labeled as "380Y/200, 50 hertz, 400Y/230, 60 hertz," or something along those lines.

So the question boils down to this: "What voltage does the machine require, and is that voltage available at its intended location?" I am not convinced that you know that answer. I think you may have had a mis-communication with the manufacturer.

 

[Jesilka]

Re: Three phase Wye Connection

Thank you, Charlie. That is the point, two customers already confirmed that when the machine arrived it requires a 380 or 400 volts three phase to run and not the 220/230Volts three phase as originally stated on the label. Hence the problem with the OEM. Here is the OEM explanation of how the system is fed, because wediscover that only the line to neutral was 220: (who begin by telling us that for a three balance system I NEED 220 for sure, )! iS THIS TRUE? I think not.
"First I would like to bring light to the topic about wether the line to neutral is 110V or 220V. For three phase balanced systems the voltage between two phases is 380V and the voltage between each phase and the neutral line is 220V, not 110V. If you see 110V between the neutral and the line there is a problem on your installation.

"Here for our instrument there are three joint heaters. Each is connected between one line and the neutral. Each one is fed by 220V. If you look at the diagram there are three inputs to the thermic relay (number 6), these inputs are from the heaters which are on three phases and the output of the thermic relay is connected to the neutral line. By this drawing you can understand that the heaters are connected between the phases and the neutral line and control circuit is connected between one of the phases and the neutral line as well. It is also fed by 220V.

Again, as I have explained. --the voltage between the two lines (for each) is 380V, the voltage between one line (for each) and the neutral is 220V-- This is a WYE (Y) connection and threfore stating that the 220/230 Volts, 50/60Hz Three Phase is the same as 380/400 volts 50/60Hz Three Phase"

I believe that your prior suggestion on how to label the unit was appropriate. Thank you so much for you professional insight!

 

[charlie b]

Re: Three phase Wye Connection

Originally posted by Jesilka: This is a WYE (Y) connection and therefor stating that the 220/230 Volts, 50/60Hz Three Phase is the same as 380/400 volts 50/60Hz Three Phase

If that is what the manufacturer told you, then they are wrong. You have a mis-application; the equipment needs a voltage source that is not available, and I believe it to be the fault of the manufacturer (i.e., because of poor communication).

Your options include sending the equipment back to the manufacturer, and looking for different equipment, or buying a transformer to step up the voltage to the required level.

 

[DaveTap]

Re: Three phase Wye Connection

Ask your manufacturer if these units are dual voltage. IE 200V or 400V 3phase changed by moving jumpers like on a motor. If the heating elements are normally connected from phase to neutral at 200V, they may also be able to connect phase to phase at 220V, but from what you've said so far it sounds like Charlie is right and the "tag" is wrong

[ February 16, 2006, 02:25 PM: Message edited by: DaveTap ]

 

[Jesilka]

Re: Three phase Wye Connection

The autoclaves are for 75 liters. Thank you, It just bothers us that the OEM stated to us that in order for a Balance three phase system there needs to be 380 phase to phase and at least 220 from line to neutral. It makes us think that really they have no concept about other countries using 110 or 120 at all.

Thanks

 

[DaveTap]

Re: Three phase Wye Connection

Well in all fairness there are fewer countries using 120/240 than other voltages, and Saudi is one of them. I was surpised to hear they had 220/3phase available. The label should still have specified 380V. As a service rep I had to change a lot of things in European machines to overcome that. The Japanese at least thought ahead to have extra taps on their transformers.

You say "in order for a balance 3 phase." That comment leads me to believe you can change the operating voltage. What about unbalanced or single phase? Some of the steamers I've installed can be connected to single or 3 phase and/or be rewired for different voltages. In other words... change the machine's connections from WYE to Delta

[ February 16, 2006, 03:06 PM: Message edited by: DaveTap ]

 

[DaveTap]

Re: Three phase Wye Connection

Hi got your PM thanks
They did mis-label the machine... The voltage tag should show the line to line voltage it is wired for AND the information about the neutral required since most equipment does not require a neutral connection. If it can operate at multiple voltages or within a voltage range it should indicate that as well and should either show how the different voltages are achived or should say see schematic for details. The schematic should be attached to the inside of a control cabinet or someplace secure yet easily accessed

That being said, ask your manufacturer how hard it is to change the autoclave's operating voltage to 220v and he may tell you to just move some jumpers or change some wires. It sounds like the heating elements are currently wired in a wye pattern meaning each one goes from line to neutral (200V) if the connections were changed to delta wirng they would be line to line in your case 220v and the heating elements would probably still work although produce slightly less heat than 200V. The next concern is your pump or compressor which may be the same solution, (change from WYE to Delta) or it may require a different motor or the installation of a transformer.

Control systems are usually the only thing that required a neutral typically a 120v control sytem on a 240v machine (in USA) because it was cheaper to get components for 120v like DC power supplies, CNC controllers, indicators or accesory lights, etc. These days most multi-voltage machines solve this with a transformer also.

Remember of course that lowering the operating voltage will mean doubling the current so you will have to increase the wire size supplying th unit to compensate and if there are motor overloads or fuses you may have to change some of them as well.