208 vs 220 single phase what's the diff. besides 12Volts?
208 vs 220 single phase what's the diff. besides 12Volts?
(OP)
This may be an ignorant question, but what is the difference (if any) between 208 VAC single phase, and 220VAC single phase? (besides 12 VAC of potential) is there a diffenent connection or phase relationship?
I was told that 208VAC was noisier than the 220VAC.
Thanks
I was told that 208VAC was noisier than the 220VAC.
Thanks






RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
So if my transformer says the secondary is 208VAC, then I should be able to get 240VAC from this transformer?
The reason I am asking is that my company makes equipment stating an operating voltage of 220 VAC single phase for the main power feeder. (the 24VDC power supplies have a switch that can be set for either 110VAC primary side, or 220VAC) We have some customers that are using 208 VAC single phase to the machines, and complaining of noise issues on the low votage side to the servos and analog sensors after the 24VDC power supplies etc. Does the main power feed being 208VAC have anything to do with this?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
Normally, 208 V is obtained from 3 single-phase transformers or 1 three-phase transformer connected in wye. You can get 208 V from phase to phase or 120 V from phase to neutral.
240 V can be obtained from a single phase transformer like you have serving a house. There is also a three phase transformer connection, floating wye primary and delta secondary. The delta scondary supplies 240 V from phase to phase.
As davidbeach says, there is no 220 V service voltage.
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
You may have some grounding issues. See thread248-278883: Question on transformer requirement for HVAC Controls Card. 208V is part (two hot wires) of a three phase grounded wye system. 110V or 220V operating voltage are typically meant for single phase system with a grounded neutral.
I would do the following:
1.In the USA, do not use 208V single phase. Instead use 110V switch on your P/S and use 120V from L-N of a 208V/120V system.
2. Do not use 220V switch in the USA. Leave it for European or Asian application where 220V or 230V single phase L-N is common.
Rafiq Bulsara
http://www.srengineersct.com
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
I meant to say "It'll just run longer..." above. I only run when needed to avoid danger.
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
Another issue with 208 vs. 240 Volts is slightly higher line currents and line losses. When 120/208 Volts is used you must add higher neutral losses also.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
Servos use DC so the amplifiers are just rectifying the AC to DC. The peak DC voltage you end up with is limited to 141% of the incoming supply, so at 208V you will have 5% less top end, but still 293V. But most Servo motors are rated under 200VDC and the amplifiers limit the available peak to what the motor actually needs, so that 5% loss is not likely a problem.
Noise issues are more likely a result of poor filtering design. If the normal use is residential / light commercial where one would find 120/240V single phase service, noise is generally not a problem. But if you go somewhere that has 208V 3 phase service, like a large commercial / light industrial installation, more likely there are other things nearby that generate noise. Sounds as though someone in your company failed to anticipate that possibility.
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
This must be a smaller installation, or some location with more 120v load, and less in motors.
However, having said that, in some locations here we do have 120/208 service to residential customers. This is because of there closeness to other larger customers that require three phase.
The 120/208 service has caused some problems to some solar installers for the residentual customers. But most 240 equipment works on 208.
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
RE: 208 vs 220 single phase what's the diff. besides 12Volts?
You know that, and I know that, but often OEMs know that the average user DOESN'T know that. What they are after is not having to make and sell several versions of the product because of the different service voltages around the world.
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: 208 vs 220 single phase what's the diff. besides 12Volts?