CFL ballast polarity?

[J.C.]

Is it a general rule that a compact fluorescent light bulb will not work at
all if the 120V AC polarity is wrong? Or might it work for a time and fail
unexpectedly? Also, is the center pin usually black/hot?

This is in regard to installing a semi-antique light fixture that was never
designed specifically for CFLs. Thanks.

Jim

 

[J.C.]

Any 120 VAC-rated CF lamp should work properly in a socket wired for
120VAC.

Reading about the differences between AC and DC should clear up the
polarity question for you.

"Polarity" is just a loose term, if not technically precise for AC.

This is an old lamp to be installed in a ceiling fixture. It has two black
wires with no obvious hot vs. neutral. I'll just do a continuity check for
the center post and make that wire hot.

Jim

 

[Bob Larter]

Is it a general rule that a compact fluorescent light bulb will not work at
all if the 120V AC polarity is wrong?
"Polarity"?

Or might it work for a time and fail
unexpectedly? Also, is the center pin usually black/hot?

This is in regard to installing a semi-antique light fixture that was never
designed specifically for CFLs. Thanks.

It should work fine either way.

 

[David Nebenzahl]

Buy a cheap extension cord and cut off the female end.

Cheaper is to always carry a wire cutter and stop at
every curbside junk pile. Throw away nothing electrical
without first taking the cord.

I do that all the time. I never have to buy power cords.

 

[Jeff Jonas]

I hate to get too far off topic, but I have a comment on this.

I replaced plugs on several multivoltage appliances this year because
I couldn't find adaptors locally.

Buying new wire is easy. Buying a quality plug for the end of it, on
the other hand, is difficult to impossible.

AMEN!
We're starting to sound like Algernon
(the mad scientist from the Beatles' movie "HELP")
It's the plugs, you know . . . must use good British plugs . . .

I have a box of huge machine/industrial 3-prong plugs
with strain relief for huge wires
but they're overkill for most things.
And the hang-tab Eagle Electric household ones with NO strain relief.
Nothing in between.

 

[Jeff Jonas]

Any old wiring should be/needs to be replaced,

especially any that has any brittle insulation ...
Any time vintage or antique equipment is reused, it should be fully
inspected for secure contacts/connections.

I was mildly shocked by an old ceiling lamp (fixture?)
by the turn-switch built into an Edison socket's base.
The knob was originally plastic coated with a metal rod inside,
but enough of the plastic wore off
for the metal to make contact with something "hot" and to me.
I'm unsure if it was somehow touching the side,
or directly conducting from the center-pin-switch.
but it was not something obvious from inspection!

 

[Jeff Jonas]

If I see some 8-10 ft extension cords that appear to be durable (even though
you never really know about molded cord ends), I sometimes buy them and end
up cutting off the receptacle end to use the cord as a replaement power
cord.

A neighbor did that, discarding 26 feet of the outlet end,
so I attached a plug and I've got a nice extension cord.

I've bought new in-package stuff from flea markets, garage sales and on eBay
at drastically reduced prices.

That's why I have a box of new high quality plugs waiting for uses:
cheap at a garage sale.