Is there any way of testing 3 phase power systems to know for sure that you actually have 3 phase. Is there something specific to look for other that checking across 2 legs for voltage and then each individual leg for half the double voltage. I am relatively new to 3 phase power and any information I can get would be great.....
3 phase power
- Thread starter flmeier
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bdarnell
Senior Member
- Location
- Indianapolis, IN
- Occupation
- Retired Engineer
No offense, but your question indicates that you need training, not testers.
There are many forms three phase power and checking 2 legs and dividing the result in half is not a reliable or accepted method of determining what type of power system you have.
There are many forms three phase power and checking 2 legs and dividing the result in half is not a reliable or accepted method of determining what type of power system you have.
stormywyo
Member
- Location
- Stigler, Oklahoma
If you check A-B, B-C and A-C voltage they should be the same.. Hopefully the the line-to-line voltage. Then check each phase (A,B and C) to the grounded conductor (or neutral) and this may be either about 120 v or 277v depending on the system.
I agree that you should have proper training and should also follow all mandated safety practices when doing this. It is dangerous without training and proceedures. :!:
I agree that you should have proper training and should also follow all mandated safety practices when doing this. It is dangerous without training and proceedures. :!:
- Location
- Illinois
- Occupation
- retired electrician
Roland,
What about 3 phase 4 wire delta systems? Ungrounded systems? You have to be aware of all of the possibilities.
Don
What about 3 phase 4 wire delta systems? Ungrounded systems? You have to be aware of all of the possibilities.
Don
stormywyo
Member
- Location
- Stigler, Oklahoma
There are all kinds of possibliities. I used an example of the most common type. The phase to phase check would still be the same. And that is where the training would help.
james wuebker
Senior Member
- Location
- Iowa
Mike Holt has some good books in his web site to help you with this. Easy to learn from. Check his site out.
Jim
Jim
ramsy
NoFixNoPay Electric
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Check me here, but I beleive one poor man's test for seperate phases requires a grounded conductor and load test, as follows:
1) If neutral or grounded cl/amps are less than any phase cl/amps, then phases are different.
2) If neutral or grounded cl/amps >= phase cl/amp sums, then phases are the same.
Or would this rich man methods do the trick.
Fluke 9040 Phase Rotation Indicator
1) If neutral or grounded cl/amps are less than any phase cl/amps, then phases are different.
2) If neutral or grounded cl/amps >= phase cl/amp sums, then phases are the same.
Or would this rich man methods do the trick.
Fluke 9040 Phase Rotation Indicator
Thats what I was looking for. I probably did not word my question very well. I was wanting to know a method or tool that would indicate that there are indeed 3 different phases instead of 3 lines of the same phase or a couple of sets of 240 single. We have a very old building and it is sometimes difficult to know kind of power wires coming through conduit to an outlet or junction box or anywhere for that matter.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
flmeier,
What do you do for a living?
What do you do for a living?
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