LEDs don't like this installation!

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wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
why oh why does my LED strobe
no dimmer...
k&t switched neutral
drives a 60w resistive filament just fine



Toggle switch to old k&t jbox
I remember it was a switched neutral [not sure of this]

Home depot LED fixtures,
work fine on a bench
Home depot LED fixtures,
strobe on the ceiling

Ceiling jbox supplying [l-n; l-g =120v] [n-g=0v "not certain on the n-g voltage"]
Ceiling box power drives incandescent 60w lamp just fine drawing .5a
I tried reversing the leads both on the bench and at the k&t


IMG_20151229_132621.jpg

IMG_20151229_132146.jpg
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Three terminal dimmers which use a neutral or the EGC as a voltage reference will not work properly when on the neutral side of the load. Two terminal dimmers, which might work with incans in this configuration, often do not work well with some types of CFLs and LEDs.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
What is the voltage at the light location with no load and the switch off?....yes this will be "ghost" voltage, but the current draw may be low enough that the "ghost" voltage could drive the LED.
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
its a problem with the sw neutral


yeah, but what's it?

I had another one where the LED would strobe unless you lost the grounding conductor

that was
it would strobe with the switch open

this one is strobing with the switch closed in
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
What is the voltage at the light location with no load and the switch off?....yes this will be "ghost" voltage, but the current draw may be low enough that the "ghost" voltage could drive the LED.



I'll measure but I remember there was no problem with the switch open, it strobes with the sw closed in
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
Are we talking about capcitive coupling?
Could be

I had a big clock generator installation that used alot of capacitive coupling, never really understood it!
the signal had to jump over some 277/120 xfmrs when it go to next bldg

I had to figure out why the 1600a cb opened, prove it safe and then got to close it back in

theres a video somewhere...
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
Fiberglass, always. Always. Please :thumbsup::)


fiberglass product weight 18lbs
FLIP-N-LITE LADDER - TYPE 1A weight 12.5 lbs
excellent ladder - without compare for service work!



DIMENSIONS
Base Spread (in.)
41 in
Maximum Reach (ft.)
10
Ladder Height (ft.)
6
Rung/Step Depth
3 in
DETAILS
Ladder Rating
Type 1 - 250 lbs.
Number of Steps
5
Ladder Type
Step Ladder
Product Weight (lb.)
18 lb
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Could be

I had a big clock generator installation that used alot of capacitive coupling, never really understood it!
the signal had to jump over some 277/120 xfmrs when it go to next bldg

I had to figure out why the 1600a cb opened, prove it safe and then got to close it back in

theres a video somewhere...

Ive heard in places such as the middle east where 127 volts is being phased out to 220 electricians often have this problem. The switch only breaks one hot, and because the open hot is next to the EGC for some distance, the lamp glows dimply from the capacitive circuit which forms. I could also imagine this on a 3 way circuit... but I need to draw it out to confirm.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
fiberglass product weight 18lbs
FLIP-N-LITE LADDER - TYPE 1A weight 12.5 lbs
excellent ladder - without compare for service work!



DIMENSIONS
Base Spread (in.)
41 in
Maximum Reach (ft.)
10
Ladder Height (ft.)
6
Rung/Step Depth
3 in
DETAILS
Ladder Rating
Type 1 - 250 lbs.
Number of Steps
5
Ladder Type
Step Ladder
Product Weight (lb.)
18 lb

Safety trumps a bit of extra weight. If you touching something live, that ladder will be worse then bare feet.
 
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