208 3ph to 440 3ph transformer

Reply

  #1  
Old 04-06-11, 02:49 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
208 3ph to 440 3ph transformer

I have a 440 volt 3 phase motor that I would like to run at my shop. I have 208 volts 3 phase available. Is this going to be tough to do? I've looked in Grainger 's & other catalogs and can't find a transformer to match these specs. TIA Tim
 
Sponsored Links
  #2  
Old 04-06-11, 02:51 PM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Upvotes: 0
Received 42 Votes on 40 Posts
What are the specs on the motor? HP rating, running current, etc -- anything you can get from the nameplate. What type of machine does it power?
 
  #3  
Old 04-06-11, 05:01 PM
Member
Join Date: Dec 2010
Location: usa
Posts: 243
Upvotes: 0
Received 0 Votes on 0 Posts
Generally you would have to take a 480V to 120/208Y transformer and reverse feed it. Of course you would need to fuse it at both sides based on the size of the load. These fellows can guide you through this but other than a specialty transformer that is one suggestion. Size of the transformer will vary, depends on the load.
 
  #4  
Old 04-06-11, 05:29 PM
Justin Smith's Avatar
Member
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,546
Upvotes: 0
Received 0 Votes on 0 Posts
Is this a commercial location?
 
  #5  
Old 04-06-11, 06:54 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,943
Received 20 Votes on 15 Posts
Originally Posted by JimElectric View Post
Generally you would have to take a 480V to 120/208Y transformer and reverse feed it. Of course you would need to fuse it at both sides based on the size of the load. These fellows can guide you through this but other than a specialty transformer that is one suggestion. Size of the transformer will vary, depends on the load.
JimElectric has it right. You can special order a 208 volt to 480 volt transformer, but it's just a stock transformer with a special label made for it.
 
  #6  
Old 04-06-11, 07:33 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
I'm not sure of the HP of the motor. It is on a Hardinge DV 59 lathe. Small motor not more than 1 hp maybe less. IT is at a commercial location. I have 3 phase 208 presently. At least thats what I'm told. I'm not an electrician. If I remember correctly, voltage across white & red, or white & blue etc gives me 110 volts. Thats ,means its 208....correct?
 
  #7  
Old 04-06-11, 07:38 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
Originally Posted by CasualJoe View Post
JimElectric has it right. You can special order a 208 volt to 480 volt transformer, but it's just a stock transformer with a special label made for it.
So I can use a 480 volt transformer even though my motor runs on 440 volts? How much would a transformer cost? Maybe I should look for a used one? If the transformer made for 3 phase then I only need 1 transformer? Thanks Tim
 
  #8  
Old 04-06-11, 07:58 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Upvotes: 0
Received 13 Votes on 11 Posts
So I can use a 480 volt transformer even though my motor runs on 440 volts?
Actually nominal standard voltage is 480v not 440v so unless the motor is very old it is 480. A motor shop may be able to reconnect it internally for 240V if available. If you have only 208 you could probably use a buck boost transformer to raise the voltage to 240 or the motor may have a wide enough tolerance to run on 208v.
 
  #9  
Old 04-06-11, 08:05 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
Originally Posted by ray2047 View Post
Actually nominal standard voltage is 480v not 440v so unless the motor is very old it is 480. A motor shop may be able to reconnect it internally for 240V if available. If you have only 208 you could probably use a buck boost transformer to raise the voltage to 240 or the motor may have a wide enough tolerance to run on 208v.
I'm thinking the motor is very old. late 50s maybe early 60s
 
  #10  
Old 04-06-11, 08:14 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Upvotes: 0
Received 13 Votes on 11 Posts
Originally Posted by TimH View Post
I'm thinking the motor is very old. late 50s maybe early 60s
Haven't probably been 440 since residential voltages were 110v and that was a lot further in the past. You really need to read the name plate. There is probably even a diagram for connecting it for a lower voltage.
 
  #11  
Old 04-06-11, 08:20 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,478
Received 22 Votes on 17 Posts
I'm thinking the motor is very old. late 50s maybe early 60s
I had to log in to let everyone know that statement had me laughing so hard that I almost choked. If something from the late fifties is "very old" then I'm absolutely prehistoric.

I've probably worked on more motors that were built in the 1920s to 1940's than ones built in 1960 or later. The older motors were more often rated at 208-220/440 volts and the newer ones will be 240/480. Before you get all concerned though about your motor requiring 440 volts you need to carefully examine the nameplate as a single voltage (especially 440) motor is actually quite rare. I strongly suspect that you do have a dual voltage motor and it can be easily reconnected for the lower voltage. If this machine has a "magnetic starter" you may need to replace the operating coil (some coils are dual voltage) and you most likely would need to change the "heater elements" on the overload relays.

There are other things to consider but first get all the nameplate data so we can help you to make an informed decision.
 
  #12  
Old 04-07-11, 01:31 AM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Upvotes: 0
Received 0 Votes on 0 Posts
Majorty of the triphase motour are dual voltage rated so changing to other voltage is not that super hard but will have to watch out the starter heater strip that part you will have to change it anyway.

I know you mention commercal location so the best answer is get a electrician they will know what to do with the set up and many time they will try to advoid useing the transfomer much as possible as long the motor have multi voltage rating that is not a issue but single rated voltage motour for that size is pretty rare unless you snag a 575 volt motour or straght 480 volt motour.

Most lathe motours can able run on 208 without major issue if they are connected on 240 volts { that part you will have to look at the nameplate and it will mention wiring diagram to verify correct connection}

If your lathe motour actually draw about 4.5 amp range @ 240 volts so the 208 it will draw about 4.8 the most { at 480 it will be about 2.3 or so amps } so you will need a small triphase transfomer like 3 KW size I don't know how easy to snag that unless you get three single phase transformers and wire up the secondary in delta fashon but have to grounded one phase per Code requirement { Your electrician will know this }

Hope that help you a bit

Merci,
Marc
 
  #13  
Old 04-07-11, 10:37 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,478
Received 22 Votes on 17 Posts
{ Your electrician will know this }
Assuming that the electrician knows something about three-phase commercial and industrial circuits. Many residential-only electricians wouldn't have a clue.
 
  #14  
Old 04-07-11, 04:46 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
I was talking to an electrician today. He said that a 208 to 480 transformer should be OK. He said its within 10% so should be good.

Anyone have an opinion on this?
 
  #15  
Old 04-07-11, 05:08 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Upvotes: 0
Received 13 Votes on 11 Posts
Probably cheaper to just reconnect the motor for 240v assuming it can be reconnected. You really haven't told us about the info on the name plate. Till you do suggesting a transformer is premature. in my opinion.
 
  #16  
Old 04-07-11, 07:43 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
Originally Posted by ray2047 View Post
Probably cheaper to just reconnect the motor for 240v assuming it can be reconnected. You really haven't told us about the info on the name plate. Till you do suggesting a transformer is premature. in my opinion.
I've been told the motors in Hardinge Lathes do not run on multiple voltages. I have considered just replacing the motor with a 208 volt motor. Again I've been told that is difficult to do. The motors are 2 speed which I'm told complicates things.
 
  #17  
Old 04-07-11, 07:50 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 12,893
Received 47 Votes on 40 Posts
That all depends if this is just a motor you are hooking up or a complete CNC Lathe package/machine. If it is a complete package then changing the voltage might not be a good option due to all the other electronics that may be on it.

A transformer will likely cost you about $250 depending on the KVA rating. There are bunches of used ones on Ebay if you want to start bidding. Otherwise around me there is a place that deals with used electrical parts like that, maybe there is one by your too.
 
  #18  
Old 04-07-11, 07:59 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
Originally Posted by Tolyn Ironhand View Post
That all depends if this is just a motor you are hooking up or a complete CNC Lathe package/machine. If it is a complete package then changing the voltage might not be a good option due to all the other electronics that may be on it.

A transformer will likely cost you about $250 depending on the KVA rating. There are bunches of used ones on Ebay if you want to start bidding. Otherwise around me there is a place that deals with used electrical parts like that, maybe there is one by your too.
No its not a cnc lathe. Just a plain old ( 1960s era ) manual lathe. Not even a coolant pump on it $250 isn't too bad. Actually the price of the lathe is really good. I just hate the hassle messing with a transformer.
 
  #19  
Old 04-07-11, 08:30 PM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Upvotes: 0
Received 0 Votes on 0 Posts
For the multispeed reversable lathé unit it better off use the transfomer to boost it up to proper voltage level.

There is too many things can go wrong with multispeed reversable triphase motor. so keep it simple there.

Merci,
Marc
 
  #20  
Old 04-08-11, 08:15 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Upvotes: 0
Received 42 Votes on 40 Posts
I agree the 208V -> 480V transformer is the way to go in this case.
 
  #21  
Old 04-08-11, 02:42 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
Final question, I hope. the lathe has a 1 HP motor What size transformer do I need?
 
  #22  
Old 04-09-11, 02:37 PM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Upvotes: 0
Received 0 Votes on 0 Posts
I will suggest 3 KW 3Ø transfomer is the smallest one I know so far but I think there is a smaller one on market but not sure the reason why I suggest 3 KW size due you may start and stop pretty fequenet and it will have some power to spare in case you get a larger one the 3 KW can handle up to 3 HP motour with out much issue { with 480 hooked up at the motour } otherwise 5 KW will do it just fine with that size.

Costwise I am not too sure yet.

so there is few options you can go from there.

Merci,
Marc
 
  #23  
Old 04-09-11, 03:00 PM
Member
Thread Starter
Join Date: Jun 2001
Location: USA
Posts: 378
Upvotes: 0
Received 0 Votes on 0 Posts
Thanks foir the input. Now I have to start looking for a transformer.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: