3 phase question have 208 v, need 460v

Status
Not open for further replies.

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I just got more info from the customer : 208-230/460 VAC 2 hp 7.8-8.2/3.1 FLA 1725 rpm or 208-230/460 VAC , 2 hp 5.6/2.8 3450 rpm
Thank you for your help.
That appears to just be the motors. What about any controls? You need to look at the machine nameplate, not just the motor nameplates.
 

kwired

Electron manager
Location
NE Nebraska
Is this just a single motor machine and no other loads?

why mention 1725 "or" 3450 rpm? Chances are it is designed for one or the other and won't work so well with "the other". The high speed motor is going to attempt to do work at least twice the rate as the low speed motor before we even look any further into details about the driven machine.
 

Stevenfyeager

Senior Member
Location
United States, Indiana
Occupation
electrical contractor
You will need to find out if it has a starter that uses line voltage for control, or a small step down transformer with adjustable input taps
( most likely) . If it is line voltage, you will need to change the starter coil, and don’t forget to change the overload heaters or dial adjustment if so equipped to match the load amps at the new voltage.
Thank you. This is all Greek to me. I may have to pass this job on to a friend of mine who does more commercial.
 

Stevenfyeager

Senior Member
Location
United States, Indiana
Occupation
electrical contractor

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
this is the machine she is buying
Just tell your customer to reach out to the manufacturer. Their website says other voltage options are available. Don't count on being able to field convert this in the field as your current will be about double at 208 and some components may be undersized.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
Although it's not really your job, it might be helpful to confirm with the customer that the standard power unit can handle the duty cycle they would be using.

From the manual:
"NOTE 2: Standard HBD units, i.e. not equipped with high cycle power unit, are not designed for high cycle use. High cycle use is defined as 12-15 motor starts per hour for 3 or more consecutive hours. If your application requires high cycle use, you must upgrade the standard power unit with a high cycle power unit."

Perhaps she already has this covered, but you never know.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Let me ask my stupid question!
208V is usually associated with Wye system. You say to use a 208 delta for the primary. How is the 208 configured to be Delta?
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Let me ask my stupid question!
208V is usually associated with Wye system. You say to use a 208 delta for the primary. How is the 208 configured to be Delta?
You are starting with a whole new system. Doesn’t mater what the old system is configured as, delta or wye. The voltage is what maters. You could have a wye-wye , or delta-delta if you wanted to. Delta wye is the most common, and usually the most stable combination.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
Let me ask my stupid question!
208V is usually associated with Wye system. You say to use a 208 delta for the primary. How is the 208 configured to be Delta?

The supply system is 208V wye.

The transformer is a load connected to this supply. They do not need to be the same.

Delta:wye transformers are the most common and generally most easily used. The new derived wye is easily grounded and you don't have the neutral impedance problems found in wye:wye transformers.

Jon
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
Let me ask my stupid question!
208V is usually associated with Wye system. You say to use a 208 delta for the primary. How is the 208 configured to be Delta?
As others stated already. No different than a standard step down to 208 application in a 480Y building. The 480 side will be delta and the 208 side will be Y.
 

Stevenfyeager

Senior Member
Location
United States, Indiana
Occupation
electrical contractor
Help ! the manager isn't liking me passing the job along. She says the man who installed the trash compactor told her no additional power needs to be run for this tool. I took a photo today of the switch of the compactor nest to where the new box tilting machine will go. It was a used machine they brought a couple of years ago and the installer told me we didn't have the right voltage the day he installed it. (Even though we called and asked which 3 phase to install for the machine before we did any work :( ) The man said, "ok, not problem, I'll just make the change in the machine." I was out of my mostly residential experience realm. So I noticed the old 460 volts sign still on it today. This photo is only a switch, not a transformer, right ? I know we have 208 only going into the machine.
I am going to put a '208 volt' label over the 460 v. There is no way he switched my 208 to 460 and that was his label, correct ?
Please help, thank you.
 

Stevenfyeager

Senior Member
Location
United States, Indiana
Occupation
electrical contractor
here is the existing compactor switch that the compactor installer says I don't need any additional power run for the tilting machine
 

Attachments

  • IMG_7263 (2).JPG
    IMG_7263 (2).JPG
    79.3 KB · Views: 15

Stevenfyeager

Senior Member
Location
United States, Indiana
Occupation
electrical contractor
I called the mfr today and he said it is hardwired and comes with a hand control. The other two machines were hardwired, I can do that.
But I am questioning the compactor installer's message....."no additional power needs run" ?
 
Status
Not open for further replies.
Top