Fluorescent tube ballast replacement

Started by bkenobi, April 16, 2016, 01:26:44 PM

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bkenobi

#30
Simple fixes always become projects.  I had my wife go to the local electrical store and pick up the correct tombstones for these fixtures.  As it turns out, while they fit, they are missing a connection to neutral.  I'm not sure whether this is an issue or not.  The original lamp holders have the 2 spring loaded contacts that attach to the blue/white or red wires.  On the blue/white side, there is a second white wire that connects to neutral when the bulb is installed (contact pushes out and connects to second white wire).  This is fine and all, but the new tombstones do not have this.  Is there any reason I can't just connect the white wire from the ballast to both the white lamp holder wire AND neutral?  When the bulb is installed, this is functionally identical.  When the bulb is not present, the ballast would think that it is present and be hot presumably.  I don't plan on having bulbs pulled from the ballast, so I don't see any difference.

Here's the new lamp holder:
https://www.platt.com/platt-electric-supply/Lampholders-Fluorescent-Linear-Medium-Bi-Pin/Leviton/13357-N/product.aspx?zpid=283663


Brian H

So you are now trying to use the older style ballasts. The new electronic one you gave the connection diagram for. Does not use the Neutral into the tombstone.

The tombstone has two wire clamps for each of its internal contact. So you can push two wires into each contact. If you have to have three whites together. Then you should be able to wire nut or splice them all together.

bkenobi

Yes I am going back to the original ballast. If I look at the original wiring, the neutral and white are tied together when the bulb is installed. Worth the bulb removed the neutral is not connected. As a result, the ballast is not powered when the bulb is pulled. I'd I connect both whites to neutral then the ballast is always hot bulb or no bulb. Is that an issue?

bkenobi

Well this is frustrating. I replaced the ballast with identical part number, both connectors, and a new(ish) bulb. The only change is that the ballast is now connected to neutral instead of that other connector (functionally identical with bulb installed). The light does not come on. If I rotate the bulb with the switch on, the light comes on. No idea now since it's basically a new fixture.

Brian H

Maybe a bad contact in the tombstone.
If you have the tube installed in its normal locked in position. If you gently rub the tube from end to end with your hand. Does it then light?

bkenobi

I installed new lamp holders/tombstones so they should be good. I can light the bulb by rotating it in the socket but haven't tried ribbing it. I have a fixture over my workbench that sometimes requires touching the bulb to get it to start.

dave w

Quote from: Brian H on April 30, 2016, 01:27:41 PM
If you gently rub the tube from end to end with your hand. Does it then light?
I have never heard of this. Are you building a static charge to "fire" the bulb?   -:)
"This aftershave makes me look fat"

Brian H

Not sure if it was static or adding some extra coupling to the fixtures ground plane.
I know in ancient years when I worked for Pratt and Whitney. Monday when they turned on the fluorescent lights. One of the electricians use to have a long pole with a wire brush on it and connected to the metal grounded columns by a long wire. Use to rub the ones that didn't light to fire them.  ;D

bkenobi

I got everything back installed and working.  In order to get it working, I had to play with the ground (sanding all connections).  It still didn't work initially, I had to use BrianH's special procedure.  After turning the lights on/off and touching the bulb a few times, it seems to function correctly every time.  Strange but my wife seems happy that I don't have all the tools in the kitchen so whatever.   :'

Brian H

I had a few fixtures in the cellar. During the summer when it was humid. I sometimes had to touch the tubes to get them to light.

dave w

Quote from: Brian H on May 01, 2016, 06:49:02 PM
Not sure if it was static or adding some extra coupling to the fixtures ground plane.
Yeah, enhancing the ground makes more sense. Old geezer brain was not warmed up yet (6L6's)
"This aftershave makes me look fat"

Brian H

I have seen new modern high end audio equipment using 6L6's and other low level amp tubes.
Some audio purist's feel that tube equipment sounds more clearer.

Knightrider

Hybrid amp. Better power handling. Better sound. More headspace. Best amp I ever owned.
Remote control is cool,
but automation rules!

JeffVolp

Quote from: Knightrider on May 02, 2016, 10:53:53 PM
Hybrid amp. Better power handling. Better sound. More headspace. Best amp I ever owned.

I'd challenge any tube amp to beat the class AB transistor amp I designed and built over 40 years ago.  It has 4-channels, with each capable of 200W RMS into 4 ohms, and a power supply capable of 1KW peak, 500W sustained.  It has protection against any overload causing secondary breakdown in the output transistors.  You could short the output at full blast, and it just folded back until the overload was removed.  I'm still using it today.

I built a single channel to use as a servo amp and 400Hz power supply back at the lab.

Jeff
X-10 automation since the BSR days

Knightrider

I'm drooling. These days, I see guys pushing to 2 ohms. Says it hits harder. I'm a lover, not a hitter. Rich sound is my priority,  bass is only part of the equation.  Total harmonic distortion is important to me.
Remote control is cool,
but automation rules!