3 Phase Low Voltage in Mexico ( San Jose Iturbide, Guanajuato) 1

[Ipaloja]

I have a question regarding Low Voltage 3 phase system in Mexico. The German client is asking me to confirm the local voltage available. And my office is located in Minneapolis MN USA, so I am not sure what voltage levels are available in San Jose Iturbide, Guanajuato, Mexico.

The client suggested:
- 254/440V 60Hz +-10% or
- 265/460V 60Hz +-10% or
- 275/477V 60Hz +-10%


I think all the options he offered are wrong.

Can someone confirm that Mexico has two 3 phase Low Voltage systems:

127V (phase to neutral)/ 220V (phase to phase) 60 Hz +- 10% and
220V (phase to neutral)/ 440V (phase to phase) 60 Hz +- 10%

thank you!

 

[jraef]

As a general rule they follow the North American standards, 480/277V, but in poor areas, you get whatever they have. If you design around 480/277V for 3 phase 4 wire systems, then use NEMA standards for equipment (460V +-10%) you should be fine.

None of those other voltages relate to any standards, those are some engineer's number crunching values. The "460/265" is probably related to the NEMA equipment specs, but in reality the NEMA spec for 460V relates to motors which don't use the neutral, so the 265V is meaningless and the service should not be described that way. The DISTRIBUTION voltage standard will be 480Y277V.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[Ipaloja]

Thank you Jraef! your comment was helpful. I did think what the client was saying was a bit odd, but I needed someone to confirm it, so thank you!

 

[waross]

Note that standard motor voltages are multiples of 115 Volts and standard supply voltages are multiples of 120 Volts.
460 Volt rated motors are used on 480 Volt systems.
You won't find 480 Volt rated standard motors.
You may find 460 Volt rated transformers but these will be very old, dating back to the 1950s and early 1960s when standard voltages were being migrated from multiples of 110 Volts, at the rate of about 1/2 Volt per year.
From 110:220 Volts to 112:224 Volts to 115:230 Volts to 117:234 Volts to 120:240 Volts. Back in those days the standard voltage was changed every 5 years.

The point is: Someone far away seeing 460 Volt rated motors in a catalogue and looking for 460 Volt transformers to supply them may be frustrated or confused.
North American standards allow for a possible voltage drop between the supply transformer and the motor terminals.
Bill
--------------------
"Why not the best?"
Jimmy Carter