Previous in Forum: CAD Drawing   Next in Forum: How Much is the Implementation of the New Standard Going to Cost?
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
2 comments
Rate Comments: Nested
sheperd
Participant

Join Date: Aug 2011
Posts: 4

TRANSFORMER RATINGS

10/05/2011 7:31 AM

why transformers are always rated in VA insteads of watts
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
PWSlack
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#1

Re: TRANSFORMER RATINGS

10/05/2011 7:32 AM

Because they don't dissipate their VA rating as heat. If they did, they wouldn't be transformers - they'd be convector heaters.

__________________
 "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
kvsridhar
Guru
India - Member - New Member

Join Date: Sep 2009
Location: Temporarily at Ashburn, VA
Posts: 2744
Good Answers: 164
#2

Re: TRANSFORMER RATINGS

10/05/2011 8:39 AM

They can deliver a certain current at a certain voltage. The power factor is decided by the load. If it is a heater, the VA will be equal to watts. At the other extreme, if it is a capacitor, the W will be almost zero. So, when a transformer is manufactured,since it is not known what the load on it will be, it is rated in VA.

__________________
 Nothing worthwhile can ever be taught, it can only be learnt.
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
Register to Reply
Have a Different Question?
2 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!

Previous in Forum: CAD Drawing   Next in Forum: How Much is the Implementation of the New Standard Going to Cost?

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Education:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (161 right now)
Show Members
Advertisement