Flourescent Lighting Fixture Starters

[hbiss]

So, the other day I disassembled the starter and this iswhat I found. The filament was completely black, which tells me a shortoccurred. One of the leads to the capacitor (I think this a capacitor, not surenot familiar with starters) and pin terminal was missing. The casing had asmall indention on the internal side. The starter is a Damar 40W starter. Whenthe starter was removed, we noticed obvious damage since the external pins andphenolic base was awkward. When the continuity check was performed between theexternal pins to the casing, one pin was shorted to the casing. I believe thispin was the one with the missing lead and caused the indention. This is basedon the external pin configuration during removal. During the inspection, itappears the casing of the Damar starter is weaker compared to some otherstarters I pressed against. So, I’m thinking that possibility duringre-installing the starter, the casing collapsed due to the pressure applied bythe mechanic. Please remember he noticed the starter didn’t seem alignedproperly and that is why the mechanic removed it. Once removed, he didn’tnotice any damage. Yet once removed after the event, we noticed damageimmediately. So, I am confident this damage happened during re-installation. I’mwondering has anyone else experienced this type of event with a Damar starter?Also, I believe based on the internal damage that is why we measured 5 volts fromthe casing to ground. Any suggestions?

Just the name suggests cheap Chinese junk. However the glass tube inside is normally black so that means nothing. It's a bi-metallic switch, not a filament. And yes, they did put a capacitor across it to minimize AM radio interference when it operated. Don't think they do anymore. As I mentioned before, any of the metal can starters I have ever seen had a cardboard sleeve liner inside the can to protect against the can being shorted to the inside components. I suspect that the lack thereof was a Chinese cost cutting measure.

I can't say that I come across very many fixtures that use starters these days other than an under cabinet light above my desk here that died a few months ago. It's probably 15 years old and even back then it used a starter with a plastic can. Not that that was any good because it broke apart when I tried to remove it. At any rate I decided to bring it into the 20 century by getting rid if the starter socket and original ballast and install a new electronic ballast.

-Hal

 

[broadgage]

Fluorescent lamp circuits with a starter switch are very common here in the UK on 240 volt circuits.
Not quite as much as 277 volts of course, but "in the same ball park"

Metal cased starters have not been manufactured for many years, plastic only since about 1970 IIRC.

The voltage on the terminals of the starter can be almost line voltage, it depends on the internal wiring, and on whether a lamp is installed or not.

 

[gar]

180717-1140 EDT

Going back to the first post.

If the fluorescent tube has to be removed to change the starter, then neither starter socket terminal should connect to either power source wire (hot or neutral, or whatever).

Each starter socket terminal goes to one contact in each tombstone socket. No bulb no continuity to anywhere except via leakage.

.

 

[hbiss]

Good point Gar. Starter being under the lamp is something I had forgotten about.

-Hal

 

[kwired]

Good point Gar. Starter being under the lamp is something I had forgotten about.

-Hal

Not all were like that though.