Transformer Grounding

[Jay Davis]

I'm building a basic power supply utilizing a simply 24V, 5A
transformer. I want to test the circuit before installing it in a case,
but I'm a bit confused about how I should ground it. I've got it
properly fused, but the third wire in the cord (the 'earth' ground)
currently isn't hooked to anything (yet, and no, I won't turn it on
until I get this figured out <grin&gt. I realize that one normally
attaches it to the chassis, but in this case, what should I attach it
to? Should I solder it to the case of the transformer? What about if I
install the power supply in a plastic case, then where should it go?

Thanks for your help!

Jay Davis

 

[Jay Davis]

Jay Davis wrote:

I'm building a basic power supply utilizing a simply 24V, 5A
transformer. I want to test the circuit before installing it in a case,

<snip>

Sorry to follow up my own post, but I should have mentioned that my
secondary is center tapped. Should I ground the earth ground to the
center tap of the transformer? I've seen this design in some places,
but I don't know if it's correct or not.

--
Jay

 

[John Popelish]

Jay Davis wrote:

Jay Davis wrote:

I'm building a basic power supply utilizing a simply 24V, 5A
transformer. I want to test the circuit before installing it in a case,

snip

Sorry to follow up my own post, but I should have mentioned that my
secondary is center tapped. Should I ground the earth ground to the
center tap of the transformer? I've seen this design in some places,
but I don't know if it's correct or not.

--
Jay

You may or may not want to have the DC outputs referenced to Earth
ground, so that is your choice. But in the absence of a chassis, I
would attach the safety ground to the transformer core in whatever way
is practical (lug bolted through the lamination stack, if there is a
hole, or lug bolted to mounting tab).

It is also a good idea to have a fuse in the hot lead of the primary
wiring.
--
John Popelish

 

[Jay Davis]

John Popelish wrote:

You may or may not want to have the DC outputs referenced to Earth
ground, so that is your choice. But in the absence of a chassis, I
would attach the safety ground to the transformer core in whatever way
is practical (lug bolted through the lamination stack, if there is a
hole, or lug bolted to mounting tab).

It is also a good idea to have a fuse in the hot lead of the primary
wiring.

Yep, got that fuse in there. I'll polish up one of the mounting tabs
and bolt the earth ground there. Thanks!

--
Jay