208V unit on 240V power supply 1

[chef5mate]

A local distributor insists on having a 208V 50-60HZ 3PH induction range unit plugged in on a 240V 60HZ 3PH power supply stub outs. I told him the manufacturer puts the specs 208V on the unit's data plate for a reason and when I asked him how does it affect the overall performance of the unit and its useful life for that matter, he is unable to provide me one.

Eventually, the unit has been installed, on owner's instructions. After several days of operations, the unit's display went blacked out although the unit's power supply and heating coil is good and only the indicator light is working, the cooling fan is dead and unit is no longer heating. I'm thinking about replacing the unit's inverter board.

The machine is a induction stock pot range manufactured by Cooktek in Chicago. Model No. MSP7000-200 bearing Serial No. 6467-17121-C0102 rated 7000 watts and with voltage rating of 208V 50-60HZ 19.5A 3PH

I would really appreciate any good advise.

 

[waross]

At 208 Volts @ 50 Hz the volts per Hertz ratio is 4.16.
On 60 Hz any inductive components should be safe from saturation up to 250 Volts @ 60 Hz.
However some other components may be subject to over voltage damage.
240 Volts three phase is often three wire or four wire delta. Is this the case?
Four wire delta gives phase to neutral voltages of 120V, 120V and 208V rather than 120V,120V, and 120V.
If the control board is expecting 120 Volts and instead gets 208 Volts you can expect to see the magic smoke.
You may wish to use a transformer to drop the voltage before connecting a replacement machine.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ScottyUK]

Hi Bill - induction hobs are high frequency devices, they're a pile of electronics and an H-bridge driving an air-cored coil. The normal rules about saturation don't apply in that way here. Being consumer-grade electronics (not industrial or military) they're designed and built to tight margins and a 15% over-voltage may be too much for it to tolerate.

Agree about a transformer to drop the supply a little.

 

[Paulusgnome]

According to the datasheet for that cooker, as downloaded from the manufacturer's website, it will operate between 200V and 240V.
Link

 

[chef5mate]

Thank you all for the very helpful tips. I have managed to persuade the bldg administrator which is also the owner of the kitchen to install a transformer dedicated for his kitchen only (Thanks, Waross and ScottyUK).

Yes, Paulusgnome, based from the Instructions Manual, though unit is spec'd with voltage range of 196-220V, factory have confirmed it will run from 200-240V power supply. Thanks.

As added information, unit has a 3-board set inverter module - filter, power and controller board. Though electrical current stops right after the filter board that's still good, I'd still prefer to replace he whole 3-board set inverter and requested to include the CPU (software programming) just to be sure all is in order.

Thank you very much again folks for the assistance. Really appreciate it.

Chef5mat3