sharing a neutral

[Besoeker]

It's important to note that Besoeker has altered this drawing by adding the "ground disconnected" and "neutral still connected" tidbits in there. So he has tried to make his opinion appear to be true by altering it when in fact he is STILL wrong and can't seem to admit it.

I haven't altered the drawing, just added text. The drawings are lifted straight from the PPT presentation.
IF the bits that look like resistors ARE resistors you cannot determine the 160V/80V split shown in the final slide. For example, suppose they were both 1 ohm. Then, as a voltage divider, the split would be 120.4V/119.6V. Not 160/80.
So, that leaves two possible conclusions.

1. The "resistors" are resistors and the presentation shows them but ignores them in the calculation. (So why show them in the first place?).
2. Or the "resistors" are not resistors but are intended to represent the usual center tapped transformer arrangement used to get 120-0-120 with the center tap used as the neutral in which case the neutral remains shown connected and only the ground is disconnected.

In either case, the presentation is wrong or, at best, very misleading.
And that's not good.
For safety, it's rather important to understand the difference between ground and neutral.

 

[steelersman]

Or the "resistors" are not resistors but are intended to represent the usual center tapped transformer arrangement used to get 120-0-120 with the center tap used as the neutral in which case the neutral remains shown connected and only the ground is disconnected.

wrong again. Don't try to analyze it so much. It's not that difficult.

 

[Besoeker]

Don't try to analyze it so much. It's not that difficult.

You're right.
It isn't.
But it is important to understand the difference.

 

[LarryFine]

And I still cannot get your quote to be shaded like alot of others do. I wish I could figure that out.

Copy and paste this into your next reply:

[quote=steelersman]And I still cannot get your quote to be shaded like alot of others do. I wish I could figure that out.[/quote]

 

[cschmid]

Wow 11 pages and still the op has not been able to glean the info necessary..

Ohm I understand the sensitivity of the semiconductor but yet I doubt that 118v would be of much problem..118v does not fall out of the 10% that the POCO is allowed to vary the incoming voltage..

So I wonder what else is on this phase of the circuit that could could cause a variation in the voltage for a short period of time..

I would like to know if the changing of the refresh rates of the monitors could cause the frequency to spike repeatedly and if that could also affect the life of the semiconductor in the coffee pot..

Nice job of referring Bob..

 

[ohm]

Wow 11 pages and still the op has not been able to glean the info necessary..

Ohm I understand the sensitivity of the semiconductor but yet I doubt that 118v would be of much problem..118v does not fall out of the 10% that the POCO is allowed to vary the incoming voltage..

So I wonder what else is on this phase of the circuit that could could cause a variation in the voltage for a short period of time..

I would like to know if the changing of the refresh rates of the monitors could cause the frequency to spike repeatedly and if that could also affect the life of the semiconductor in the coffee pot..

Nice job of referring Bob..

That 7A spike when the printer is being used seems a bit much but the TVSS should handle that.

And I've recorded thousand volt spikes on 120V lines, without any noticeable damage. I even recall a typical home will limit spikes to 600V because of inter-electrode capacitance, device clearances etc.

I don't believe the monitor refresh rate could be the culprit, especially if the monitor is LCD. Old style magnetic deflection coils on CRT's might be a problem if there was resonance with some other piece of equipment.

I would return the coffee pots for credit and switch brands. They might even have a recall on them, which would explain everthing.

 

[76nemo]

I hope to live as long as this thread. Open the pot and ohm out the TCO:grin: I believe you'll find it open:wink: