Electrical Spikes in the House

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
08/04/2011 17:46

I had an interesting experience this morning. I am having some renovation work done in my house. The workers wanted to mix some cement in a container but when they tried to use a hand held motor to stir it the electrics went off. They asked me if I had a stronger supply. The problem was that the RCD (main breaker which trips if there is an earth fault) was tripping. I checked the insulation of the motor and it was perfect which puzzled me somewhat. Ah well, I did not want the work to stop so I removed the earth connection and I got the operator to wear rubber gloves just in case. Surprise surprise, the RCD tripped again. I could not understand this because the earth connection was disconnected and thus it was impossible to trip the RCD. This was a real challenge for me. I got over the shock in a few seconds and realized that the motor (commutator type) was causing voltage spikes in the system which was picked up by my "Elko Voltage Protector" which you know all about and it was tripping the RCD. I removed the Protector temporarily and and the motor continued to work normally. I reconnected the earth for safety.

ismet

PS: for the more technically minded, here is a picture for a commutator where electricity is fed to the windings through carbon brushes and lots of sparks takes place. http://forums.ereplacementparts.com/power-tool-repair/167-makita-ls1013-miter-saw-blade-keeps-running.html

Brinsley


Joined: 04/04/2009
Posts: 6858

Message Posted:
08/04/2011 17:54

Ismet

So your system works! I would've thought that you had more faith in the box you're marketing, even though it's made in China!

Looking at your web site, how does one 3 pin plug in of your unit protect all the circuits on the interior electrical board?



Richard

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
08/04/2011 18:01

Oh Richard!!! If the voltage goes outside the set limits it sends a small current to earth which is picked up by the RCD and trips off the whole electricity in the house.

ismet

Brinsley


Joined: 04/04/2009
Posts: 6858

Message Posted:
08/04/2011 18:12

Goes to show that I'm not so sparky!



Richard

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
09/04/2011 13:04

Ismet,

Might this not also be the case with pumps and motors in washing machines, dishwashers, vacuum cleaners etc? I have one of your gizmos and have had not experienced this, but some might in the future.

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
09/04/2011 13:15

Vaughan,

Pumps and motors in washing machines and dish washers do not uses carbon brushes because they all work at 3000 rpm or lower. You need commutators when you want to go over 3000 rpm like the vacuum cleaners. So vacuum cleaners could cause a trip but of course the power rating and how clean the brushes are all play a role. So we have to be vigilant and have this in mind if the RCD trips. This is why I shared this information with everybody. We use the vascuum cleaner in the house quite often but no problem so far.



Of course if this becomes a seriousproblem, I will have to consider using inductors and capacitors to filter out such spikes. On the other hand, its a good thing that my devices detect these spikes over a certain limit.

ismet

PS: I was wondering when you would come in with your comments as one of the more technically minded persons on this forum