Ordering new 600 ton press. I want to clarify some specs...

[milemaker13]

We are about to order a huge new press and I just want to make sure I have a few things right. This being the largest machine I have installed yet so I don't want it to come in wrong.

I am told the machine is 460v 3 phase and it was noted that the main motor is a Y- configuration.

Our building has about 492 volts phase to phase, and has a neutral. Our lighting ,for example, is 277 volts. I assume this is a 480 Y system, correct?

Rule of thumb has always been 10% so the machine should be OK with up to 506 volts. But nowadays new equipment will sometimes have a lower tolerance.

And would it matter if my building was 480 Y or delta? Does this mean the machine will require a neutral connection? Why would they specify the motors being Y wound?

I need to see if I can get some better info, but this is what I have so far.:?

 

[iwire]

You are fine, a 460 volt tagged machine is intended to be connected to a 480 volt source.

 

[milemaker13]

Yes, I would agree.

What about the Y- motors? I understand the differance but didn't think my incomming power would relate to that. Unless its their way of saying it needs a neutral connection...

 

[iwire]

A little more on the voltage.

As far as the Delta / Wye issue.

It makes no difference if the main motor is Wye or Delta, the motor only needs 3 hot phases.

As far as the entire machine with info you have provided I can't tell if the machine needs a neutral or not, but if it does you have one available.

 

[milemaker13]

OK, thank you for the info.

 

[augie47]

It might be worth asking for a bit more detail such as HP and if the machine comes with a starter/drive..
You need the HP to assure you have adequate service and the type of starter needed may vary depending on HP and your service size.
Some areas have POCO restrictions on large motors starting "across the line"

 

[jim dungar]

The equipment is furnished with a 45kVA transformer. Your service only needs to be able to supply that transformer.

Similar conditions occur with a VFD, 430.122 says the feeder is sized to the input of the VFD, there is absolutely not mention of considering the output of the VFD.
670.3(A) mentions duty cycles of equipment permitting 'reduced size conductors', similar to the feeder demand factor found in 430.26.

You are required to comply with the equipment nameplates, your are not required to determine the validity of the nameplate information.

 

[augie47]

The equipment is furnished with a 45kVA transformer. Your service only needs to be able to supply that transformer.

Similar conditions occur with a VFD, 430.122 says the feeder is sized to the input of the VFD, there is absolutely not mention of considering the output of the VFD.
670.3(A) mentions duty cycles of equipment permitting 'reduced size conductors', similar to the feeder demand factor found in 430.26.

You are required to comply with the equipment nameplates, your are not required to determine the validity of the nameplate information.

I'm loosing my mind. Where did the 45 kva transf. enter the equation. I've read iy 3 times and still don't see that,
(looks more like a reply to Yazermann's thread)

 

[jim dungar]

I'm loosing my mind. Where did the 45 kva transf. enter the equation. I've read iy 3 times and still don't see that,
(looks more like a reply to Yazermann's thread)

:ashamed:OOPS:ashamed:

Wrong thread.
mea culpa.

 

[kwired]

Yes, I would agree.

What about the Y- motors? I understand the differance but didn't think my incomming power would relate to that. Unless its their way of saying it needs a neutral connection...

When they say it is a wye - wound motor all that means is the coils that make up the windings are connected together in a wye configuration. It will not matter what the input source was derived from as long as it is 460 volts (within acceptable tolerances), 60 hertz, and there are three phases 120 degrees apart. That means for supply corner grounded delta would work, ungrounded delta would work, typical wye sytem would work, high impedance ground on a wye would work, even pulse width modulation (basically a manufactured three phase supply) from a variable frequency drive would work, all of those provide three phases with right voltage, frequency, and phase angles.

If you need a neutral it is probably for something other than the motor.

 

[Cow]

Don't be scared, order it up!!!

 

[milemaker13]

You got it boss.... Should I get 2 in case this one wears out? Lol. :happyyes:

I think they are about to pull the trigger:thumbsup:

 

[kwired]

You got it boss.... Should I get 2 in case this one wears out? Lol. :happyyes:

I think they are about to pull the trigger:thumbsup:

Buying 2 is probably cheaper than buying one plus one of every spare part to have on hand just in case

 

[milemaker13]

Probably right. It could also reduce downtime, not waiting on overseas parts. But, not sure we have room for such a large 'parts cabinet'. Lol.

 

[pfalcon]

... Our lighting ,for example, is 277 volts. I assume this is a 480 Y system, correct? ...:?

Not necessarily. Our plant has several 3 wire and no 4 wire systems:

480V Y solidly grounded
480V D ungrounded
480V Y high impedance ground

Only three phases are run in the buss. Protective ground is from the grounding system local to the equipment. To run lighting we install a lighting transformer that provides the neutral but supplies no other equipment.

The standard for 480V is +/- 10%. Automotive industry oftens suggests designing for 460V since low voltages are more damaging than high voltages. Sounds like your plant had lots of problems in the past and cranked up to 492 to avoid overcurrents.