Three-phase power supply US?
Three-phase power supply US?
(OP)
I am working on getting a breathing air system approved for use in North America.
This is a brand new market for me, and i have a basic questions.
I am trying to find out what the most commonly used three-phase powersupply is onshore and offshore?
Thanks in advance.
This is a brand new market for me, and i have a basic questions.
I am trying to find out what the most commonly used three-phase powersupply is onshore and offshore?
Thanks in advance.






RE: Three-phase power supply US?
277/480 Volts wye
In Canada;
347/600 Volts wye
Occasionally 240 Volts delta and 480 Volts delta. Delta service is not available in many areas.
Bill
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"Why not the best?"
Jimmy Carter
RE: Three-phase power supply US?
Is it accurate to say that 480v is the standard for motors aswell?
RE: Three-phase power supply US?
No it is not fair to say 480V is the standard for motors. Probably 2/3rds of all motors are 208 or 240.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Three-phase power supply US?
"Other countries" are 'abroad'. Divided by a common language!
RE: Three-phase power supply US?
If you want it to be more universally acceptable, you could consider using a VFD and a 208V 3 phase motor. That way if they have 208V, 3 phase, great, if they have 240V 3 phase, the drive is fine with 240V input and giving 208V output, and if the motor is 3HP or under, you can get a VFD that will accept 240V 1 phase or 3 phase input without derating. If they have 480V available, they will likely also have 120/240V single phase available as well for lighting and other single phase loads.
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Three-phase power supply US?
If there is more than occasional air required, the power requirements may be too great for the reasonable use of single phase.
In the smaller sizes there are motors available that are rated for 200:230/460 Volts or 208:230/460 Volts. If you will be over about 10HP or 15HP you may want to consider a 230/460 Volt rated motor slightly oversized so as to be able to function properly on nominal 208 Volts on a day when the voltage is at the lower limit of the utility's voltage tolerance range.
Another option may be to include a pair of auto-transformers in open delta boost configuration to boost 208 Volts up to 240 Volts for 208 Volt applications.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Three-phase power supply US?
NOTE: Motor nameplate voltage is listed as 230V nominal for 240V systems. And 460V nominal is listed as for 480V systems.
Sometimes 200V or 208V is listed for 208V systems. Common 3 phase motors are dual voltage in smaller sizes, meaning that the windings either field wired for series (higher voltage) or parallel (lower voltage)and listed as 230/460V.
Hope this helps and good luck,
Dave
RE: Three-phase power supply US?
If any of you wonder what kind of a system i am talking about you can check out www.pusteluft.no
As ScottyUK says, when i say offshore i mean on platforms and installations in the sea :D I cant believe I didnt realise there was a difference!
230/460v 7,5HP is what I need then. I have compared IEC frames(112) to NEMA frames and found that I need a 184T frame.
A question on the side: Hazardous locations. I am used to the IEC 3-zone system, the class/div is new to me. As Class1 div1 involves both zone 0 and 1, is it given that a Class1 Zone 1 certified equipment would be rejected at a class1 div1 site, or would it be sujected judgement by authority having juristiction?