Electrical Requirment for Parklift

LarryFine

Master Electrician Electric Contractor Richmond VA
I'm trying to determine if the lift requires `120/208V/3Ph or 230/480V.
Neither; it requires 400/230Y, or as we usually call it, 416/240Y. You could provide that by connecting three XXX/240v transformers with the secondaries in a Y configuration, with XXX meeting your existing supply.

Now, there is the 50Hz issue. This means it will run at 6/5 of designed speed. I've read that the frequency difference will let you run this on 60Hz at a different voltage, but not sure whether it's higher or lower.

Anyone? Frye?

ron

Senior Member
Now, there is the 50Hz issue. This means it will run at 6/5 of designed speed. I've read that the frequency difference will let you run this on 60Hz at a different voltage, but not sure whether it's higher or lower.

Anyone? Frye?
This was one of the long answer questions on my PE exam a while back.

This link has some good bullet points.
http://www.50hz60hz.com/60hz-motor-running-on-50hz-power-supply.html

Jraef

Moderator
Staff member
From a V/Hz standpoint, 480V 60Hz is the same as 400V 50Hz. But as mentioned, anything with a motor will run at 20% higher speed. On motors connected to centrifugal pumps or fans, the Affinity Law for motor speed means the pump or fan will require 172% more mechanical power, but the motor will only be delivering 120% mechanical power, so it will overload. What we don't know is whether or not any of this will be a problem for this equipment. Most likely there is a hydraulic pump in there so it will most likely be a Positive Displacement pump and not subject to the Affinity Law. But we have no idea.

A second issues is that of control systems. In foreign (to us) equipment like that, they often use L-N as a source of 230V control power. In a 480V 4 wire system here, the L-N voltage will be 277V, usually outside of the tolerance for anything with a coil. But if they have switch mode power supplies with auto-ranging input, it may not matter. Again, we have no way of knowing.

I love it when people buy equipment from EU sources without bothering to find out if it will even work here, then expect some poor unsuspecting electrician to "just get-er done". Easier said than done and by the time you get it all right, it would ahve likely been les expensive to use a North American resource for the equipment. Oh well...

tortuga

Senior Member
I'll chime in that you could also use a VFD, we commonly do.
I see 415Y230V 50hz equipment often enough.
If they can ship it 60HZ or if its mostly a resistive load (like semi conductor oven) you might be able to get the utility to drop you a custom Xformer bank.
Yes I have been on a project where this was done, its actually not that hard.
I used to be in the camp of "why not just buy a north american 480V"... but you see how common 400 and 415 3PH is all over and with specialized manufacturing equipment its just the standard.
480 V panels can be run at less than 480 and 415 is actually classified as 400V in some countries.
220Y127 is actually more difficult as the 127 is just outside our spec for 120V stuff.

texie

Senior Member
From a V/Hz standpoint, 480V 60Hz is the same as 400V 50Hz. But as mentioned, anything with a motor will run at 20% higher speed. On motors connected to centrifugal pumps or fans, the Affinity Law for motor speed means the pump or fan will require 172% more mechanical power, but the motor will only be delivering 120% mechanical power, so it will overload. What we don't know is whether or not any of this will be a problem for this equipment. Most likely there is a hydraulic pump in there so it will most likely be a Positive Displacement pump and not subject to the Affinity Law. But we have no idea.

A second issues is that of control systems. In foreign (to us) equipment like that, they often use L-N as a source of 230V control power. In a 480V 4 wire system here, the L-N voltage will be 277V, usually outside of the tolerance for anything with a coil. But if they have switch mode power supplies with auto-ranging input, it may not matter. Again, we have no way of knowing.

I love it when people buy equipment from EU sources without bothering to find out if it will even work here, then expect some poor unsuspecting electrician to "just get-er done". Easier said than done and by the time you get it all right, it would ahve likely been les expensive to use a North American resource for the equipment. Oh well...
Well said. I would add that there also will be NRTL issues in many jurisdictions.