ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
New fan motor for Panasonic
by HotLine1. 06/25/19 03:53 PM
Burning out of return(white) side of 120volt rec
by crselectric. 06/14/19 02:15 AM
Video door bell causing chime activation of coil
by JoeTestingEngr. 06/13/19 12:43 PM
Troubleshooting Voltage Drop Across Relay
by gfretwell. 06/09/19 11:49 AM
Apple Recalls Three-Prong Wall Plug Adapters
by Admin. 06/05/19 09:06 PM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 7 guests, and 11 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Harmonics Again #129616
06/15/05 06:24 PM
06/15/05 06:24 PM
D
Dnkldorf  Offline OP
Member
Joined: Dec 2004
Posts: 1,064
nowhere usa
I am reading where Harmonic currents get trapped in the Delta windings in a D-Y transformer, they circulate and heat them dry transformers up.

Question, Do they ever make it back to the POCO transformers, or do they stay circulating in the SDS transformer?


Dnk.....

Tools for Electricians:
Re: Harmonics Again #129617
06/19/05 12:29 AM
06/19/05 12:29 AM
renosteinke  Offline
Cat Servant
Member
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
I think we have to be careful, as all the various 'models' we use have their limitations.

I would say that, first of all, nothing gets "trapped." Converted to heat or motion, perhaps...but it simply can't just sit there accumulating.

Secondly, we are dealing with AC. While all electricity is invisible- we have to use our imaginations to try to understand it- AC has a few quirks that DC lacks. These quirks exist because AC is always in a state of change- even when nothing is happening. Induction, reactance, impedence, and even capacitance are strongly influenced by this constant flux.

The whole point of harmonics is the effect certain things have on the time something happens....delay some current a little, and it gets added to the current from another phase, thus overloading the neutral. I would say that, at the transformer, where the neutral originates, that all time-affected matters balance out- perhaps generating some heat in the process.

I expect that this "balancing" may not be perfect- that is, the current may not return to being exactly in sync with the voltage. This is 'power factor,' and is something that is sent on to the power company grid. Another facet of "power quality," this is addressed with capacitors.

Re: Harmonics Again #129618
07/12/05 11:43 PM
07/12/05 11:43 PM
S
sierra electrician  Offline
Member
Joined: Feb 2005
Posts: 219
North Fork, CA USA
>Secondly, we are dealing with AC. While all electricity is invisible-

I've seen it John I swear to god.

Rob


Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Niko
Niko
Campbell, CA
Posts: 356
Joined: August 2006
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
255,877 Are you busy
191,856 Re: Forum
181,618 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.029s Queries: 14 (0.014s) Memory: 0.9520 MB (Peak: 1.0756 MB) Zlib enabled. Server Time: 2019-06-26 14:18:05 UTC