Heat treatment machine power supply issue

[Emad Shaaban]

Hi every one
A heat treatment machine (pro heat 35) works with power supply 470v/575v..please see attachment
What options I have to make this machine works on 380v power supply

 

[davidbeach]

A transformer.

 

[waross]

What David said.

 

[Mark_Markus]

Best for temporary or low-budget solutions: sse a Step-Up transformer. ​

 

[Emad Shaaban]

What if user the standby 380v generator and then increase its excitation,will that affect winding withstanding?

 

[waross]

What if user the standby 380v generator and then increase its excitation,will that affect winding withstanding?

You have to check the generator nameplate to see if 480 Volts is an available voltage.
It may need a change in the connections and it will need an adjustment of the AVR.
Another issue with the generator is the maximum Volts-per-Hertz of the windings.
If you try for a voltage much above the rated V/H, saturation will limit further increases of voltage.
And, the voltage based on the V/H At 60 Hz is 6/5 times the maximum voltage at 50 Hz.
You may have to adjust the governor up to 60 Hz.
While reconfiguring the generator is most likely possible it is not a simple adjustment.
Your best option is a pair of 380:110 (or the closest available ratings) transformers configured as an open delta auto-transformer.

 

[Emad Shaaban]

Thank you every one, I tried to find 380/480v step up transformer ,but it seem to be unavailable on the local markets on my region.
Can you please suggest other options please

 

[waross]

Read my bLIPs;

Your best option is a pair of 380:110 (or the closest available ratings) transformers configured as an open delta auto-transformer.

Pit falls:
Volts per Hertz.
380 Volts suggests 50 Hz.
60 Hz transformers used on 50 Hz must have the maximum allowable voltage reduced in the ratio of 50Hz/60Hz to avoid magnetic saturation.
With a maximum voltage of 575 Volts you may consider limiting 50 Hz voltage to 489 Volts.

Try a 480 Volt to 120 Volt single phase transformer configured as an auto-transformer.
480V + 120V = 600V
600v x (380V/480V) = 475 Volts. (600V x (50Hz/60Hz) = 500 Volts = Safe from saturation.

Capacity:
Assume 40 Amps.
120 Volts x 40 Amps / 1000 = 4.8 KVA minimum.
Substitute your current and do the math to determine the needed capacity.
Two such transformers are needed.
Open delta, auto-transformer boost connection.
I have used this solution many times going from 480 Volts to 600 Volts and a similar solution going from 600 Volts to 480 Volts.

 

[Emad Shaaban]

Thanks everyone,thanks waross.
Actually my application is to step up 380v /480v
please excuse my limited experience,
3ph 380/110 transformer is available .it not single cores.
I need to be fully aware of connection .I should be very appreciative if can be sketched for me

 

[waross]

Fun with numbers:
Boost 380 Volts to 490 Volts.
What transformer capacity is needed for a 50 Amp load?
Three phase transformer: 50 A x 490 V x 1.73 / 1000 = 42.4 KVA x one transformer
Three single phase transformers: 50 A x 283 V / 1000 = 14.15 KVA x three transformers.
Two auto-transformers in open delta: 50 A x 110 V = 5.5 KVA x two transformers. 380V:110V transformers.
Total transformer capacity needed:
Conventional transformers = 42.4 KVA
Open delta auto-transformer = 11 KVA
Check the prices.

 

[waross]

This is for 240/480:120/240 Volt transformers.

 

[Emad Shaaban]

Thank you(WAROSS) very much with all respect for your time and efforts .that was very supportive .

 

[waross]

Thank you for the thank you.
Anecdotally when I worked for a contractor in Western Canada, we had a customer with a 480 Volt service.
In Eastern Canada they had a similar plant with a 600 Volt service.
They would frequently sent 600 Volt equipment out west and it was my job to spec and plan the transformers.
Then they built a new plant. BC had changed the standard voltage up to 600 Volts.
The new plant had two MCCs, one at 480V, one at 600V.
They used a two transformer auto-transformer set to drop from 600V to 480V.
But if a location was fed from one MCC it could not be changed to feed from the other MCC.
Then they started switching equipment around.
Over half of the time, there was a voltage change.
I had pairs of transformers sitting beside equipment all over the plant going from either 480 V to 600 V or from 600 V to 480 V.
My suggestion is not based on book theory.
It is based on a lot of successful field experience.
Good luck.

 

[Emad Shaaban]

Impressive experience.I will get it started and keep my experience posted here.Thanks again

 

[waross]

Rental companies supplying the oil industry in Western Canada have both open delta and full wye autotransformers available for rent.
Many petro-chemical plants have 600 Volt systems. Almost all rental generators are 480 Volts.
When a 600 Volt plant needs temporary power, they rent a 480 volt to 600 Volt auto-transformer along with the 480 Volt generator.