Trying to set up heater to send to Malaysia

[deetz]

We have a heat treat oven that we want to send to our Malaysia facility. It is powered by 240v 60hz to buck-boost transformers that change it to 210v which then goes to another transformer that makes it 100v to each leg of the heating coils. I was looking at getting a large enough VFD to switch Malaysia power (415v 50hz) to 240v 60hz to run the machine. There are no motors but there is old temperature meters that still are using tubes. Will this work?

 

[VEBill]

Are heating coils more expensive than all those high power transformers? My instinct says to go back to the company that supplied the heating coils and ask them about making variations designed for various voltage standards. You're still left with the rest of the system, but I assume that the heating coils are most of the power.

Hopefully someone else will be along to answer your actual question.

 

[deetz]

I'm not worried about the heating coils, they are a resistive load so 50hz won't affect them. It's the VFD that supplies the transformers and controls that I worry about. Just not that familiar with VFD characteristics.

 

[OperaHouse]

TUBES!!!!! Your best bet would be to change out the temp controller now to a universal voltage type rather than wait for it to go bad over there and risk a long shutdown.

 

[deetz]

Very true. If it didn't come with a bunch of spare parts and be as cheap as it is we would do something different. Thanks.

 

[jraef]

Transformers as a rule do not like PWM feeds, as the output of a VFD would be. It can be done, but it stresses the transformer (thermally) and it's customary to use a transformer with special core designs to help reduce added eddy current losses in the magnetics.

But also I think it would be prudent and most likely less expensive to change out the old controller than to add a VFD just for that device. if not, how about a small static frequency converter just for that device's power feed, leaving the rest to run on 50Hz?

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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[VEBill]

OP: "240v ...transformers ...210v ...another transformer ...100v to ...heating coils." and "...not worried about the heating coils, they are a resistive load so 50 Hz won't affect them."

You're correct that the heating coils don't care about 50 vs. 60 Hz. But all those high power (?) transformers designed for 60 Hz (?) aren't going to like 50 Hz. They'll run hotter. Perhaps much hotter.

jref: "Transformers as a rule do not like PWM..."

Running low on options...

 

[deetz]

Thanks guys for the time and all the good and valid advice. The next step is going to be to set it up with a trans to get my 415v then hook it up to the VFD to get my 240v with 60hz that is already here, and see what happens. That's what the top brass wants me to do. Will let you know what transpires.

 

[waross]

Buy a 50 Hz transformer for the voltage you need. It may be a special order. If you use a 60 Hz transformer it must be rated for at least 120% of the 50 Hz voltage.
Fast forward 50 years or so; trash the tube type controller and buy a cheap, modern temperature controller.


Bill
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Jimmy Carter