Another lighting question...

[gflat65]

I had a dual brand X 175W ballast that I was told was 10-15 years old when I bought it. It was running some older 15K XM's in a standard looking reflector set up (base mounts into a piece that mounts to the reflector). I tried running the 15K Iwasaki's on those ballasts in those fixtures and it would not fire them.

In the back, I had a Blue Wave 175W ballast (M57) running 12K Sunburst over the QT. The fixture is largely homemade. I bent some stainless steel plate and bolted a socket to it via an L brace. I tried one of the 15K Iwasakai's in it and they fired up immediately. I have another M57 ballast that i used to run (ballast has less than 2 years use). I figured I could put the Bluewave and ~2yr old M57 to the 120 and run the Iwasaki's. I rewired everything but left the fixture's mounted where they were. With the Bluewave and the ~2yr old M57 hooked into the reflector assemblies over the 120 (where the dual 10-15 year old ballasts were), neither ballast would fire the Iwasaki's and neither fires the XM's as bright as the 10-15 yr old ballasts did. Now, the 10-15 yr old ballasts are firing the 12K and it looks brighter.

My confusion... The Bluewave ran the Iwasaki's on the homemade reflector, but not on the manufactured reflector- the only difference being the socket. The dual ballasts (10-15 yr old) seem to be running the 12K brighter than the bluewave did (whiuch ran the Iwasaki's at one point). What is going on? I would at first think the sockets may not be stout enough of soemthign crazy like that, except the older ballasts are burning brighter than the other ballasts with both lights (even though they couldn't fire the Iwasaki's... Any ideas?

 

[fish tanked]

thats odd. if you figure it out post what fixed it. Have you tried hitting it with a hammer?

 

[cee]

Probably the caps on the older ballasts, as they tended to "overbuild" them back then (higher capacitance). Also, the older ballasts may not be producing enough voltage to fire the Iwasakis. I actually "customize" my ballasts to my bulbs by playing with the capacitance and the taps on the ballasts, and can achieve about any PAR number, and, to a lesser degree, color temperature, I want on just about any bulb.

As far as the reflector, I don't know... Your question reminds me of some of those college problems where they give you more information than is necessary to solve the problem.

Dave

 

[gflat65]

Dave,

I'm known for too much... I give it all in case anything strikes out.

Why would the Iwasaki's fire on the Bluewave on one tank and not on the other? Could the socket (base) make that much of a difference? That was the only difference between locations and firing or not.

 

[cee]

One socket may not be totally isolated from ground, and hence you may be leaking current to ground through the socket. Either that or the contact resistance of the wiring/connections is causing a large voltage drop. Does it trip the GFCI (this probably doesn't matter, since the problem isn't likely on the line side). Has to be one or the other...

Dave

 

[gflat65]

Thanks Dave. I've got that line coming in from a different room, so the lights on the 120 aren't on a GFCI... I'm gonna run independent lines for each tank, soon though. I'll move a socket around and see what I can figure out.

Is there a common sense way of changing out caps to achieve different things? If I can add a different cap to my M57's to get them to fire more bulbs, that would be great.

 

[gflat65]

Well, after spending all day playing around with every combination possible so I could figure out why the bulbs fired in one place and not another, the only conclusion I can come to is that it is the sockets. I put one of the Iwasaki's in the socket that had fired them before with the Bluewaves, but running one of the old ballasts and it fired. After hours of mind numbing Zen (tried not to get too ticked off...), I ended up with the old dual ballasts running both of the Iwasaki's over the 120, but with new sockets. The sockets I used were much older then the ones in the reflector. The ones from the reflector (wouldn't fire bulbs) connected the supply wires by a fitting that crimps onto the wire and then acts as the nut for the screw that holds it in place (either one end of the metal jacket inside the socket, or to the center spring). The ceramic was rated for higher power, but the metal jacket was a smaller gauge than the older ones that ended up firing the bulbs. The older sockets allowed me to screw the wires directly into the back of the socket, rather than using wire nuts. I'm not sure if it was the metal jacket gauge, the wire connections, or a little of both, but those seemed to be the only differences between sockets.