How do you determine the gauge of stranded wire? Measuring thickness would probaby be inaccurate.
I have a very old sewing machine that needs a new electrical cord because the insulation is disintegrating. Problem is, it’s stranded wire so I can’t tell what gauge it is, and the service manual doesn’t specify.
The foot control says “95-145 volts, 0.7 ampere.” Does this suggest a likely wire size?
Janet
Replies
For a sewing machine, just about any size wire will do. The thinnest you can normally use for appliance wiring is #18, which is good for about 14 amps. My wife's mega-machine has 1.1 amp on the nameplate.
The bigger concern is simply that the wire be sufficiently rugged to stand up to its use. A sewing machine cord is apt to be plugged and unplugged, trampled on, pinched in the machine case, etc, so you should avoid anything that seems too lightweight.
Sewing again; another electricity question
Thanks, Dan, the machine works again!
While driving to the hardware store, I remembered an electrical supply business nearby. Surely they would be expert enough to determine the gauge of the wire just by looking at it.
"16-gauge. How much do you want?"
"Same as these old wires--rounded up a bit, just in case." And I really did need the extra wire. Beats me how anybody gets all those strands around the really short threaded part. As soon as I started working the strands, they kinked up and took up even more space. And so I kept lopping off the ends and starting with fresh wire. It took so long the store had closed so I couldn't start over with 18-gauge.
The Underwriter's knot had to go. Even after softening the insulation in boiling water, there was no way to tie it tightly enough to fit inside the housing.
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While sewing, the light suddenly dimmed and for a moment I thought it was a mistake in the wiring. Then I realized it was just the electric iron heating up. That thing draws so much electricity, it affects everything else in the room, including the overhead light. Does that indicate a problem with the wiring?
Janet
Yeah, I was going to say that managing the stranded wire can be a challenge. I'll often get out a soldering iron and "tin" the wire (coat the end in solder) to make it more manageable.
An electric iron draws A LOT of current. While you usually won't notice the lights dimming in a reasonably modern house, in an older home with maybe a 60-100A service and relatively few circuits it wouldn't be unexpected.
What Dan said.
Conventional light appliance cord is sometimes called "zip cord" - it's just got the two stranded conductors, and if you feel it you might feel a bump on one side that would indicate the neutral side.
Make sure you have something called a "strain relief" grommet sized for your cord. If your old cord was zip cord, make sure it still fits the new cord, as the insulating may be more durable but thinner. The strain relief grommet prevents you from accidentally pulling the wire out of the appliance.
Just buy an extension cord
Just buy a 2 wire (ungrounded) extension cord and cut the socket off.