HPS to MV Conversion: Underpowered lamp?

[gramirez2012]

This is a thread continued from the comments on my HPS to MV Conversion gallery. I figured it would be more efficient to have a thread versus comments on the pic

The most recent comment I posted was:
"It ran for several hours and still looked dim. I turned it off, and when I took out the bulb, it was insanely hot (felt like it was burning through my glove). I put in a known good, clear bulb and it showed the same startup symptoms: Dim blue light, and I could see the arc tube this time. Warming up very slowly. I took a volt meter to the socket and measured 220v (the meter doesn't have 240 for some reason). It seems like the lamps are being underpowered."

What can I do to further diagnose the problem?

[Jace the Gull]

one of the neutral connection could be loose....or not wired properly.....

[gramirez2012]

one of the neutral connection could be loose....or not wired properly.....

I'll check tomorrow. Thanks

[Jace the Gull]

by the way yeah sometimes the thread may be more efficient...but I have noticed not ALL of the members actually reads the forum at all! 

[Mike]

Yeah, I read the forum periodically to catch up on things.

[A_lights]

his is a thread continued from the comments on my HPS to MV Conversion gallery. I figured it would be more efficient to have a thread versus comments on the pic

The most recent comment I posted was:
"It ran for several hours and still looked dim. I turned it off, and when I took out the bulb, it was insanely hot (felt like it was burning through my glove). I put in a known good, clear bulb and it showed the same startup symptoms: Dim blue light, and I could see the arc tube this time. Warming up very slowly. I took a volt meter to the socket and measured 220v (the meter doesn't have 240 for some reason). It seems like the lamps are being underpowered."

What can I do to further diagnose the problem?

does the ballast have a capacitor? that is most likely bad.....

[gramirez2012]

does the ballast have a capacitor? that is most likely bad.....

That's what I was thinking.

[Medved]

What is the ballast type?
If itis a series choke (I would guess for 220..240V), the capacitor play no role at all for the lamp, it is there only to fix the power factor in the input (so the installation could use thiner wires and/or lower rated switches; usually not of any concern with only single fixture).
Be aware, than HPS vs MV of the same nominal wattage have quite a different operating voltage/currents.
The current is dictated by the ballast, while the voltage by the lamp. Now if the ballast is designed for higher arc voltage lamp, it mean the lamp current it feed is lower for the same rated power, so the lower arc voltage lamp will run there underpowered.
Now what does not fit as much is, than HPS for markets with 230V mains aredesigned with ~70..90V arc voltage (depend on rated power, higher power mean usually higher voltage), while the MV's (all) for 95..130V (again, higher rating mean higher voltage in that range) arc voltage, so I would rather guess the MV would be overdriven on a HPS ballast of the same wattage rating...