Transformer wiring

[stew1234]

Hello, I ordered a pair of Triad Magnetics transformers but am unsure of what to do with the gray line illustrated below. I haven't seen that before on a primary winding.

Thank you.

 

[mike567]

GRAY wire is not ground!!! It is a tap on the primary. The green/yellow wire is a ground. Gray wire to ground equals instant poofage.

 

[ItsAllInMyHead]

@stew1234 - I'm not sure why post #1 was edited unless you requested it to be changed. If so, it's better to just EDIIT your first post (and note the edit). No need for mods to do that.

So, for clarity, are you asking about the GRAY or the GREEN/YELLOW? You originally asked about the GRAY wire.

 

[rayma]

First post refers to a tap on one primary winding (gray), not the core ground wire (green/yellow).
That gray tap can be used as specified in the data sheet to adjust for line voltage, or left open.
Never connect it to ground.

 

[rayma]

@stew1234 - I'm not sure why post #1 was edited unless you requested it to be changed. If so, it's better to just EDIIT your first post (and note the edit). No need for mods to do that. So, for clarity, are you asking about the GRAY or the GREEN/YELLOW? You originally asked about the GRAY wire.

He was indeed referring to the gray tap on the primary, not the green/yellow ground wire.
Erroneous posts deleted for safety reasons.

 

[egellings]

Hello, I ordered a pair of Triad Magnetics transformers but am unsure of what to do with the gray line illustrated below. I haven't seen that before on a primary winding.

Thank you.

View attachment 1325339

Use gray/ blue for a lower line voltage.

 

[TonyTecson]

let me guess, if those two primary coils are 120 each, then the grey tap could be 100v to allow, either 220 or 240vac options..

 

[stew1234]

Thank you that's helpful. I am aware that GRN/YEL is ground. If I am wiring white and blue to primary, what is the safest way to deal with the grey wire? I do not like that there is an extra unused primary lead.

 

[wg_ski]

Cut it off close (but not too close) and cover with heat shrink? Usually I connect unused taps to a terminal that goes to nothing, in case I want it for a different configuration later. Then heat shrink it. Start playing with tubes much and you’ll have all sorts of unused taps. And you might wish you had them back on another project.

 

[techtool]

Please get, read, and post the data sheet if you still have questions.

 

[stew1234]

Hi, yes I've read it (data sheet link below). My question remains what to safely do with the grey wire as I will be wiring primaries for 120v. For 120v the data sheet instructs you to "Input to White & Blue, jumper White & Brown, jumper Blue & Violet" but it does not reference what to do with the extra grey. wire. Thank you.

https://www.mouser.com/datasheet/2/410/VPM24_2080-844679.pdf

 

[techtool]

In the case of 120v primary wiring, the grey tap is unused but must it be insulated, as it will be live with 100v when the transformer is powered.
You are correct, the data sheet does not indicate this, but it should. Good catch.
It's there so the transformer can be used in countries with 100v power, like Japan, and others with 220v.
Best of success with your project.

 

[wg_ski]

If the data sheet doesn’t tell you to hook it to anything, it can be ASSUMED that it’s not supposed to connect to anything. All mains connected anything needs to be insulated for mains voltage. Connecting to an otherwise unconnected terminal gives it somewhere safe to go, so its not flopping around loose.