Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Blooze on February 01, 2023, 09:08:07 pm
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Kind of a dumb question, but this is my first time using an IEC power entry (snap in) and I was wondering if you make the ground wire short or make it long enough that it would be the last thing connected if the entry jack broke and came out, similar to a regular power cord? I’ve always made the ground wire the longest.
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Not too short and not too long is good with an IEC socket mains earth chassis connection. A dedicated secure chassis attachment is more critical. If some klutz kicks the jug cord, it’ll come right out of the socket before anything else happens, so no need for ‘strain relief’ length as such.
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Not too short and not too long is good with an IEC socket mains earth chassis connection. A dedicated secure chassis attachment is more critical. If some klutz kicks the jug cord, it’ll come right out of the socket before anything else happens, so no need for ‘strain relief’ length as such.
That’s kinda what I figured. Thanks for the confirmation.
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I dislike snap in sockets, they’re too finicky, if the cut out isn’t an exact match for the socket it can pull out. I much prefer inlets to be retained by proper fasteners.
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^ Good point. Something like the link below would be better. My last 5E3 build had a strain relief that snaps into the hole in the stainless enclosure (cord set, not IEC). The fit was kind of loose and I was never crazy about it, but hard to fix now.
https://www.mouser.com/ProductDetail/Qualtek/703W-00-04?qs=258DH3jk4VcghZDjT93A0g%3D%3D&mgh=1 (https://www.mouser.com/ProductDetail/Qualtek/703W-00-04?qs=258DH3jk4VcghZDjT93A0g%3D%3D&mgh=1)
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I dislike snap in sockets, they’re too finicky, if the cut out isn’t an exact match for the socket it can pull out. I much prefer inlets to be retained by proper fasteners.
This chassis was already precut for the snap-ins from Mojotone. It's all I can do to squeeze the tabs hard enough to remove it when I tried the fit.
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Several authors I've read (Blencowe,et. al.) say to wire the AC ground wire directly to the chassis, stressing it should be as close as possible to the cord inlet. ie, no longer than necessary. ymmv
I've always used that IEC inlet with the two machine screws to hold it on securely. I like the kind with a built-in fuse holder.
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+1 with pdf64 and JPK. Different manufacturers of snap-in IEC Sockets can vary dimensions :sad:
Attached is my take on IEC Socket fitting (wiring not complete). I like a 4mm SS machine screw with nut, then Earth lug with locknut.
In Australia, it is a requirement to have a dedicated chassis screw with lug (preferably Locking Earth Lug) connecting Earth terminal of IEC to chassis.
Regards
Mirek
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The snap in one I have just barely fits thru the hole. It’ll barely wiggle one installed. No way the hole could be smaller and still get it through.
Here’s where I ended up putting the grounding lug. External tooth washer, lug, then another tooth washer (internal), and locking nut.
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Blooze, excellent Ground lug. :laugh:
If I'm forced to use a snap-in IEC skt or replacing one, I place a neat strip of silastic (Translucent, NEUTRAL CURE gutter type) on the 2 sides with retainer "clips" as per attached pix. DON'T overload it, looks ugly, just enough to keep the "clips" in place plus it minimizes movement of the IEC but still remains firm.
Regards
Mirek