Talk:Inrush current

transfomers

I added some more formatting and a bit of information about transfomers on this page. I might add an equation later describing how the residual flux causes inrush current in transfomers. i forgot to login when i added it but oh well. Virtual circuit 04:08, 8 June 2007 (UTC)

cranking

Has anyone else heard "inrush current" referred to as "cranking"? I saw it here: http://ask.slashdot.org/comments.pl?sid=1077491&cid=26282677 kostmo (talk) 00:49, 1 January 2009 (UTC)

wtf?

Dear tech,

Base on my knowledge, the breaker sizing should refer to the total amp and multiply by the surge factor (1.6). Our client refuses to install the SPD(surge protection device), but they want to maintain the sizing base on the total load without the surge factor calculation. They request an advice from us. Which method of installation is correct and how do I prove it to them? For additional information, the incoming source will be from UPS. As I know, surge current might occur during the switching of the breaker. If we don’t take the surge factor into consideration, it might trip the breaker. How the surge occur during the breaker switching and what causing it?

Please assist me on this. Hope to get your prompt reply since we are in the middle of acceptance test.

Wikipedia is not a free consulting engineering source. Your best choice would be to retain the services of a licensed professional engineer in your jurisdiction, who can authoritatively advise you with respect to technical requirements consistent with the regulations of your jurisdiction. --Wtshymanski 17:45, 28 September 2006 (UTC)

ok — Preceding unsigned comment added by 2001:1A40:1410:AB00:95CB:993C:B16E:8C3F (talk) 11:46, 23 October 2024 (UTC)

Inrush

I want to upload a picture of an Inrush. But I can´t because I am no Uploader.--Noinrush (talk) 14:30, 11 February 2009 (UTC)

This edit is much better than the existing, but always user wtshymanskie will delete it: When a transformer is first energized a transient current up to 10 to 50 times larger than the rated transformer current can flow for several cycles. This happens when the primary winding is connected around the zero-crossing of the primary voltage and if the voltage drives then the induction B in the same direction like the iron core remnance has, and if the remnance is high because the Transformer was disconnected from the grid to the end of an voltage half wave. Why he delete it? --Emeko (talk) 16:37, 17 December 2011 (UTC)

I revert it because it starts off as English and gradually turns to word soup, and it doesn't say anything not already in the article. --Wtshymanski (talk) 18:39, 17 December 2011 (UTC)

I want to stand by this comment: the phase angle at which you switch on an inductive or capacitive load makes a huge difference. Switching on an (air core) inductor using a zero-crossing SSR will cause a current twice the nominal value. The original article does not contain the word "angle" and it should. It must contain this aspect of rush in behaviour or it is not complete. Almost all examples of rush in on the Internet use a sine wave starting at t=0 and a serious rush in occurs. No-one uses cosine as there would be nothing to explain (no rush in at all). All angels between sine and cosine are interesting too. — Preceding unsigned comment added by 213.125.37.155 (talk) 08:54, 29 February 2020 (UTC)

Light Fittings

Can anyone add some detail to this in respect to the inrush during lamp startup of flourecent light fittings? Manufacturers used to publish details of how to calculate the peak current during lamp start but this appears to have been withheald from todays literature. I realise that there is less inrush with modern high frequency lamps, but when a Client is insisting we maximise the number of lights per circuit, a few more technical details here would help.Ted7234889 (talk) 07:30, 9 June 2011 (UTC)

Filament bulb inrush current

I noticed the following edit by a user who thought that the resistance of a filament decreases with increasing temperature, when it actually increases with temperature:

22:12, 17 November 2015 edit by‎ 137.91.114.239

I didn't revert this edit for a few reasons:

• The text removed had no citation yet
• It may be better elsewhere in the article because filament bulbs are falling out of popularity recently.

However, I would like to see the filament bulb example restored in this article because the inrush current of filament bulbs is highly significant.

Thanks.

Tiscando (talk) 12:46, 8 March 2016 (UTC)

Regretably, it disappeared, because I thought of this, and was going to write something, when I saw this discussion. All kinds of resistive heating/lighting applications have a similar inrush current issue. There are other devices with a negative coefficient of resistance with respect to temperature; may they be considered to have negative (or inverse) inrush current... maybe it should be called outrush current :-) Sbalfour (talk) 22:38, 20 November 2017 (UTC)

Load-clamp power would refer to the ratio of supply current to load current divided by supply resistance, multiplied by the instantaneous load voltage.

(I_S)

(I_L)

R_S

x

I_L

where

I_S

is the supply current

I_L is the load current

R_S is the supply resistance

U_L is the instantaneous load voltage 142.181.126.155 (talk) 20:14, 29 October 2023 (UTC)

Inrush caused by parasitic effects of the circuit layout

Although probably very small, are the parasitic effects of circuit layout and design substantial enough to mention here? They can have design effects on microcircuits.

Mcsew2k (talk) 20:15, 17 July 2017 (UTC)