Ground switch/polarity removal question

[samdjr74]

Hi All,

I'm about to get my hands on another older Gibson amp. This one still has the poliarty switch for the ground intact and functioning. I plan to install a new 3 prong plug. When I do this do I need to remove the polarity switch from the circuit?

Thanks,
Sam

[BgTonalPursuit]

I'd wire it up modern safety standards while adding the 3-prong plug...remove the polarity switch, make sure the hot wire is fused, switch both if you have a DPDT power switch, and secure the ground wire to the chassis close to the entrance of the power wire.

[samdjr74]

I'd wire it up modern safety standards while adding the 3-prong plug...remove the polarity switch, make sure the hot wire is fused, switch both if you have a DPDT power switch, and secure the ground wire to the chassis close to the entrance of the power wire.

Thanks for the info, what do you mean by "switch both if you have a double throw double pole power switch?

[BgTonalPursuit]

Sorry it took me so long to reply...I've been tweaking a reverb-o-express beast for a while...in addition to finals coming up.

I was saying that you should put in a DPDT switch, and switch both the hot and neutral from the wall, if it isn't already done.

[mhuss]

Actually I think US electrical code nowadays frowns on breaking the neutral connection.

Wire up a three-prong, connect the ground to a point in the chassis near where it enters, using a dedicated screw. Connect the neutral to the PT, connect the hot to the mains switch/fuse/PT (in whichever order).

Remove all AC connections to the ground/polarity switch, but leave it in place for cosmetic reasons.

--mark

[Mikeyblac]

Does anyone have a diagram for this project?

[Reeltarded]

Look at nearly any layout almost anywhere.

[Mikeyblac]

I'm new to this so I guess I don't know where, sorry

[Reeltarded]

I don't have a special layout available on this device or i'd toss it out to ya.

Look in the files section forums at the layouts of an Express or whatever and see if it makes sense.

It's as simple as adding a lug for the N and the two other connections go just like you'll see in any modern layout, but look and ask questions..

Google Marshall 1987 layout. I just glanced at the Express layout and the Marshall shows it all much better.

[Mikeyblac]

Thank-you so much, sorry for being a dullard at this.

[M Fowler]

Yes here is a diagram.

[Structo]

That diagram is pretty good but I believe code says to attach the green ground wire to a dedicated screw near the rear where it comes in at. (all by itself)
Also make the green wire a bit longer than the hot or neutral, in case the cord ever gets yanked on, that way the ground is likely to remain connected, protecting the consumer from a hot chassis.

[Reeltarded]

I put two massive zip ties with an inch of slack on the mains in and you couldn't separate it from the amp with a bulldozer..

IEC is best though!