60hz to 50hz

[Doc13067]

I have a client who is bringing less than 100 amps worth of equipment from Greece that will operate at 50hz. I felt that the most economical way to deal with this was to install a sub panel that runs on EU 220v 50 hz. The power coming into the house is 240v 60hz. Does anyone know of a transformer or frequency converter that I could put between the 100A sub panel breaker and the 100A sub panel? If there is something that I can run Al 2/3 SER into and out of then I could have an entire load center dedicated to powering Greek equipment.

 

[electrofelon]

I have a client who is bringing less than 100 amps worth of equipment from Greece that will operate at 50hz. I felt that the most economical way to deal with this was to install a sub panel that runs on EU 220v 50 hz. The power coming into the house is 240v 60hz. Does anyone know of a transformer or frequency converter that I could put between the 100A sub panel breaker and the 100A sub panel? If there is something that I can run Al 2/3 SER into and out of then I could have an entire load center dedicated to powering Greek equipment.

We had to do something similar recently and we ended up getting a UPS which could do the frequency conversion. A VFD is another option. IT depends on the loads. Is there a substantial motor load?

 

[synchro]

Are the loads only 220V single phase L-N ?
Also, it would be wise to verify with the manufacturer(s) of the equipment that 60Hz cannot be used.

 

[ruxton.stanislaw]

What are the loads exactly?

 

[retirede]

It depends on what you’re powering. Our plant had several machine tools that were purchased used from Europe. Nameplate 380V, 50 HZ. We simply hooked them up and ran them on 480/60. The machinists had to account for the speed difference when selecting the gears for spindle speed and table feedrates. We did have to change the bulbs in the indicator lights.

 

[Besoeker3]

I have a client who is bringing less than 100 amps worth of equipment from Greece that will operate at 50hz. I felt that the most economical way to deal with this was to install a sub panel that runs on EU 220v 50 hz. The power coming into the house is 240v 60hz. Does anyone know of a transformer or frequency converter that I could put between the 100A sub panel breaker and the 100A sub panel? If there is something that I can run Al 2/3 SER into and out of then I could have an entire load center dedicated to powering Greek equipment.

For EU the voltage is 230/400V 50Hz.

 

[Speedskater]

Must 50 Hz equipment is happy running at 60 Hz. But the opposite is not true.
As noted above, motors will run fast which may be a problem.
* * * * * * * * * * * *
In the lab, we had an old second hand 1000 horsepower 60 to 50 Hz converter.
While I wasn't there, but one day it blew up. Sent flames to the roof.

 

[augie47]

Not sure it's applicable in your area but beware of the NRTL (UL) requirement on equipment.

 

[Jraef]

I have a client who is bringing less than 100 amps worth of equipment from Greece that will operate at 50hz. I felt that the most economical way to deal with this was to install a sub panel that runs on EU 220v 50 hz. The power coming into the house is 240v 60hz. Does anyone know of a transformer or frequency converter that I could put between the 100A sub panel breaker and the 100A sub panel? If there is something that I can run Al 2/3 SER into and out of then I could have an entire load center dedicated to powering Greek equipment.

As others have said, this really boils down to details, there is no “one size fits all” solution. Simplistic approaches might cause more problems that they solve and you may run afoul of regulatory issues, resulting in the only solution becoming something that must be done without permits, which then can have serious insurance risks.

All in all, I rarely see situations in which it is worth importing machinery that has not been designed to operate here. Machinery built for export will take all these little pesky engineering issues into account up front. Years ago I used to work for a company that would do this for importers after-the-fact, meaning they would import machines, send them to us and we would rebuild the electrical systems to work here and put a UL label on the control panels so they could be connected here. When the importers would see the bill for that, they rarely did it twice…

 

[Besoeker3]

As others have said, this really boils down to details, there is no “one size fits all” solution. Simplistic approaches might cause more problems that they solve and you may run afoul of regulatory issues, resulting in the only solution becoming something that must be done without permits, which then can have serious insurance risks.

All in all, I rarely see situations in which it is worth importing machinery that has not been designed to operate here. Machinery built for export will take all these little pesky engineering issues into account up front. Years ago I used to work for a company that would do this for importers after-the-fact, meaning they would import machines, send them to us and we would rebuild the electrical systems to work here and put a UL label on the control panels so they could be connected here. When the importers would see the bill for that, they rarely did it twice…

I quite agree with you especially for such relative small values. Changing the USA voltage would be the simplest option.

 

[Doc13067]

The technicians in Greece say I need 100 amps. I told the client to get me a list of all of the equipment because I would need a load calculation for what is going to be operating at 50 Hz and he said there is no load calculation to do just make sure it has 100 amp capacity lol. So I’m looking for a device that can support 100 amps and can have number two aluminum wires terminated in it so that I can drop the frequency before it even gets to the panel. That way his entire panel can be maxed out at 100 amps/50 Hz. I am sure any device that can handle a 100 amp load will be far more expensive than one that would match his actual loads because I know that a residential heater in this case is not going to draw that much. This is single phase residential so the 230/400 would not apply as that appears to be a three phase representation (since 230 x 1.732 is 400 roughly). I agree this is a complete headache not only for the reason stated above, but HVAC equipment needs to be maintained every year. He will have to fly a technician in from Greece to work on it. I have advised him not to do this, but he is determined, so I am trying to find a way.

 

[curt swartz]

You should tell the client without more detail on the equipment you can't do the job. What is so hard about getting you a spec sheet? Without knowing what you are supplying you can't help and should walk from the job.

If this is HVAC equipment and really does require 100 amps most of the load must be resistive heat which is not going to care about 50 vs 60 Hz.

If you were to install a rotary converter does the client really want it running 24/7? They will not like the sound and energy use.

You keep mentioning you need #2 AL for 100 amps. #2 is only rated for 90 amps at 75C. Who knows if this equipment is even listed for 75C conductors so you might need to size based on 60C.

Also, remember if something goes wrong with this equipment or if its were to cause property damage (fire) you will be on the hook financially and your liability carrier may not back you.

 

[synchro]

There is this unit, as well as others from the same supplier:

30 kVA 1 Phase 50/60Hz Frequency Converter

30 kVA pure sine wave 1 phase AC power frequency converter, change single phase 120V 60Hz to 240V 50Hz (vice versa) in one step by inner step up transformer for different equipment power system compatibilities.

www.gohz.com

You need to consider inrush because solid state frequency converters will typically have a limit on the peak load current that is not much more than the nominal rating. Perhaps the turn-on of the loads could be sequenced by the user if necessary. At least with a quick glance, I did not see it mentioned that this unit was listed by an NRTL.

 

[Jraef]

I did not see it mentioned that this unit was listed by an NRTL.

It's not, I have dealt with them (or tried to) for a client. GoHz is a Turkish company. They have an office here in California, but those people know nothing when it comes to NRTLs (or at least claim to not know why it is necessary).

And yes, if they are saying 230/400V, they are referring to 3 phase, so if you only have single phase power at the site, that's a SEPARATE added complication!

AND, if they meant 100A at 230V 3 phase, that's 45kVA...

This company (Georator) makes units that are BOTH static phase converters (single to three phase) and frequency converters (60 to 50Hz) in one unit. You are likely looking at around $10k (last one I had to buy was that much for 50kVA, but that was a long time ago).

 

[Flicker Index]

You have to consider what the line is used for.
If it's used for real-time clock, then the static converter commutation needs to be based on five cycles per six input cycles. If it's only induction motor, then a pulley change may do.

 

[Doc13067]

You should tell the client without more detail on the equipment you can't do the job. What is so hard about getting you a spec sheet? Without knowing what you are supplying you can't help and should walk from the job.

If this is HVAC equipment and really does require 100 amps most of the load must be resistive heat which is not going to care about 50 vs 60 Hz.

If you were to install a rotary converter does the client really want it running 24/7? They will not like the sound and energy use.

You keep mentioning you need #2 AL for 100 amps. #2 is only rated for 90 amps at 75C. Who knows if this equipment is even listed for 75C conductors so you might need to size based on 60C.

Also, remember if something goes wrong with this equipment or if its were to cause property damage (fire) you will be on the hook financially and your liability carrier may not back you.

Thank you. I’m going to take your advice and not do this job. It’s turning into a mess anyway. The client hired us on a day rate with no plans and didn’t want any invoices or anything so he could pretend he was doing all the work himself to the township plus someone else started the job so we didn’t know what we were getting into but we were supposed to just show up and do whatever he needed. He’s now run up a debt in back pay and is disputing that we should have finished and therefore aren’t entitled to any additional pay (added a second kitchen to the scope the last day we were there lol) So there are now two reasons to walk from the job. We set up a temp service on a 4x4 next to the house consisting of materials I purchased and was loaning until I did the service. Think I can take that stuff back if he doesn’t pay or will lawyers advise against it?

 

[Doc13067]

It's not, I have dealt with them (or tried to) for a client. GoHz is a Turkish company. They have an office here in California, but those people know nothing when it comes to NRTLs (or at least claim to not know why it is necessary).

And yes, if they are saying 230/400V, they are referring to 3 phase, so if you only have single phase power at the site, that's a SEPARATE added complication!

AND, if they meant 100A at 230V 3 phase, that's 45kVA...

This company (Georator) makes units that are BOTH static phase converters (single to three phase) and frequency converters (60 to 50Hz) in one unit. You are likely looking at around $10k (last one I had to buy was that much for 50kVA, but that was a long time ago).

Ok thank you. This guy is going to flip when he finds out what kind of trouble he’s having for not using 60hz equipment. And it’s HVAC it’s not a Time Machine that only exists in Europe. I don’t understand why anyone would go through the trouble for a heater. 3 phase was mentioned here only. The equipment is not 3 phase it’s 2. But it’s 220v at 50hz when we have 240v at 60hz. The 100 amp load with no specs is really the issue.

 

[Jraef]

it’s 220v at 50hz when we have 240v at 60hz. The 100 amp load with no specs is really the issue.

Yeah, I would walk away too, maybe run.

If it were just a resistance heater, frequency is irrelevant. Also if it uses an “ECM” (Electronically Commutated Motor) used in some super high-end equipment, that might not make a difference either. But if it has a standard AC induction motor on a fan or blower, the 60Hz is a big problem. The motor will spin at 6/5 speed or 120%. In a centrifugal fan, LOAD on the motor changes at the CUBE of the speed change. So at 120% speed, the fan load on the motor is 1.2 x 1.2 x 1.2 = 173%. So if it was a 1HP motor, you now have a 1.73HP load on it and it will overload. You can fix that if there is a belt drive by changing the sheave ratio, but this is no longer a purely electrical project and who gets responsibility for getting it right? I’ve been down this road before, nobody wins…

This guy (end user insisting on Greek unit) is dumb…

 

[Doc13067]

You should tell the client without more detail on the equipment you can't do the job. What is so hard about getting you a spec sheet? Without knowing what you are supplying you can't help and should walk from the job.

If this is HVAC equipment and really does require 100 amps most of the load must be resistive heat which is not going to care about 50 vs 60 Hz.

If you were to install a rotary converter does the client really want it running 24/7? They will not like the sound and energy use.

You keep mentioning you need #2 AL for 100 amps. #2 is only rated for 90 amps at 75C. Who knows if this equipment is even listed for 75C conductors so you might need to size based on 60C.

Also, remember if something goes wrong with this equipment or if its were to cause property damage (fire) you will be on the hook financially and your liability carrier may not back you.

Yeah, I would walk away too, maybe run.

If it were just a resistance heater, frequency is irrelevant. Also if it uses an “ECM” (Electronically Commutated Motor) used in some super high-end equipment, that might not make a difference either. But if it has a standard AC induction motor on a fan or blower, the 60Hz is a big problem. The motor will spin at 6/5 speed or 120%. In a centrifugal fan, LOAD on the motor changes at the CUBE of the speed change. So at 120% speed, the fan load on the motor is 1.2 x 1.2 x 1.2 = 173%. So if it was a 1HP motor, you now have a 1.73HP load on it and it will overload. You can fix that if there is a belt drive by changing the sheave ratio, but this is no longer a purely electrical project and who gets responsibility for getting it right? I’ve been down this road before, nobody wins…

This guy (end user insisting on Greek unit) is dumb…

Thank you. Yeah he’s a real peach too.

 

[Doc13067]

You keep mentioning you need #2 AL for 100 amps. #2 is only rated for 90 amps at 75C. Who knows if this equipment is even listed for 75C conductors so you might need to size based on 60C.

Just for the record, the #2 is XHHW-2. Does that have to be derated to 75 C?