I have one machine with transformer from 208 3 phase to 400 3 phase, what will happen if I connect the transformer to 360 V 3 phase as input is it will be okay or not? Because the machine comes from the USA to Egypt which has a different input voltage.
\$\begingroup\$
\$\endgroup\$
4
-
\$\begingroup\$ Be careful. These are lethal levels. \$\endgroup\$– Brian CarltonCommented Jan 27, 2015 at 15:35
-
\$\begingroup\$ Is Egypt 50Hz or 60Hz? What kind of machine, does it have motors (inductive load), electronics. Also the plate may say 50-60Hz. Do be careful. \$\endgroup\$– tallenCommented Jan 27, 2015 at 15:38
-
\$\begingroup\$ okay, I checked Egypt is 50Hz. The US is 60Hz which is uncommon from a world perspective. You need to check the data plate. There is an ambiguity in your question but I think your saying that the data plate says 208 - 400VAC 3 phase, so your okay there, but look for something that says 60 Hz, or it may say 50 - 60Hz. If it says 50 - 60 Hz then your okay. Is this a welding machine? Inverter? \$\endgroup\$– tallenCommented Jan 27, 2015 at 15:49
-
\$\begingroup\$ If you're working with 3-phase, then there's another possibility that hasn't been mentioned yet: that there are multiple ways to wire it that give you different voltages. In a Wye configuration, you have three separate circuits between line and shared neutral that are supposed to be load-balanced and 120deg apart. In an ideal world, that would cancel all neutral current, but it never works out that way. In a Delta configuration, you still have three circuits, but now they're line-to-line, with no neutral except for convenience. I'll leave the rest as an exercise for the student. \$\endgroup\$– AaronDCommented Jan 27, 2015 at 17:45
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
2
I have one machine with transformer from 208 3 phase to 400 3 phase, what will happen if I connect the transformer to 360 V 3 phase as input is it will be okay or not?
I'm taking this question as meaning you want to put 360V 3ph onto a transformer that is normally rated for 208V 3 ph. If so, don't do it - you'll likely blow fuses (due to the transformer laminations magnetically saturating.
If in fact you mean connect 360V 3 ph to the 400V side then this is less of a problem but if you are feeding it 50Hz instead of the mormal 60Hz then you might get some overheating still due to the lower frequency cancelling the effective reduced voltage. The voltage reduction is to 90% whereas the current increase due to dropping 60Hz to 50Hz is +20%. Net effect might be 10% more current and this could still cause problems.
answered Jan 27, 2015 at 19:39
-
\$\begingroup\$ There is also the issue of overfluxing when operating 60Hz transformers at 50Hz. \$\endgroup\$ Commented Feb 27, 2015 at 11:54
-
\$\begingroup\$ Thanks but I think I covered this issue. \$\endgroup\$– Andy akaCommented Feb 27, 2015 at 11:59