Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:EC37i.191018$jt2.173764@newsfe13.lga...
> Jeff Strickland wrote:
>> I thought I knew this stuff, but there is a nuance that I'm not
>> getting.
>> I have a fiber optic lighting system in my swimming pool. It takes a
>> 24v/250A light bulb. The bubl does not light, but the filiment is
>> okay. The power supply (transformer) does not put out any voltage, so
>> I bought a new one.
>>
>> The new transformer is stated to provide 40VA, but the light does not
>> come on. My guess is that a VA and a "regular" A are different.
>> What's the difference?
>
> VA is VoltAmps or Watts in DC current systems, a measure
> of power output and most commonly used with backup power
> supplies although it works on transformers.
>
> 250A is way too high for any bulb. 24V 250A is enough to run a
> MIG welder. :)
>
> It's time to start tracking. Start with the AC power to the
> transformer and make sure it's working and the breaker hasn't
> popped or the switch failed.
>
> Then take an ohmmeter and measure the bulb side of that circuit
> to make sure it's good and the bulb holder or wires haven't corroded.
> (there could be a switch somewhere in that circuit also)
>
> Hard to tell without looking at it myself.



NEW STUFF ...
I'm dumb.

The lamp has continuity at something like 1.5mohms, which is pretty close to
being open. I think I measure in at 1mohm.

I have several meters, the first one lied to me for whatever reason. My
Fluke 77 says I have 21vAC on the secondary of the original transformer and
the bulb is open until I get to the megohm range. (I think it might be the
20 megohm range to boot.)

Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:EC37i.191018$jt2.173764@newsfe13.lga...
> Jeff Strickland wrote:
>> I thought I knew this stuff, but there is a nuance that I'm not
>> getting.
>> I have a fiber optic lighting system in my swimming pool. It takes a
>> 24v/250A light bulb. The bubl does not light, but the filiment is
>> okay. The power supply (transformer) does not put out any voltage, so
>> I bought a new one.
>>
>> The new transformer is stated to provide 40VA, but the light does not
>> come on. My guess is that a VA and a "regular" A are different.
>> What's the difference?
>
> VA is VoltAmps or Watts in DC current systems, a measure
> of power output and most commonly used with backup power
> supplies although it works on transformers.
>
> 250A is way too high for any bulb. 24V 250A is enough to run a
> MIG welder. :)
>
> It's time to start tracking. Start with the AC power to the
> transformer and make sure it's working and the breaker hasn't
> popped or the switch failed.
>
> Then take an ohmmeter and measure the bulb side of that circuit
> to make sure it's good and the bulb holder or wires haven't corroded.
> (there could be a switch somewhere in that circuit also)
>
> Hard to tell without looking at it myself.



NEW STUFF ...
I'm dumb.

The lamp has continuity at something like 1.5mohms, which is pretty close to
being open. I think I measure in at 1mohm.

I have several meters, the first one lied to me for whatever reason. My
Fluke 77 says I have 21vAC on the secondary of the original transformer and
the bulb is open until I get to the megohm range. (I think it might be the
20 megohm range to boot.)

Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:EC37i.191018$jt2.173764@newsfe13.lga...
> Jeff Strickland wrote:
>> I thought I knew this stuff, but there is a nuance that I'm not
>> getting.
>> I have a fiber optic lighting system in my swimming pool. It takes a
>> 24v/250A light bulb. The bubl does not light, but the filiment is
>> okay. The power supply (transformer) does not put out any voltage, so
>> I bought a new one.
>>
>> The new transformer is stated to provide 40VA, but the light does not
>> come on. My guess is that a VA and a "regular" A are different.
>> What's the difference?
>
> VA is VoltAmps or Watts in DC current systems, a measure
> of power output and most commonly used with backup power
> supplies although it works on transformers.
>
> 250A is way too high for any bulb. 24V 250A is enough to run a
> MIG welder. :)
>
> It's time to start tracking. Start with the AC power to the
> transformer and make sure it's working and the breaker hasn't
> popped or the switch failed.
>
> Then take an ohmmeter and measure the bulb side of that circuit
> to make sure it's good and the bulb holder or wires haven't corroded.
> (there could be a switch somewhere in that circuit also)
>
> Hard to tell without looking at it myself.



NEW STUFF ...
I'm dumb.

The lamp has continuity at something like 1.5mohms, which is pretty close to
being open. I think I measure in at 1mohm.

I have several meters, the first one lied to me for whatever reason. My
Fluke 77 says I have 21vAC on the secondary of the original transformer and
the bulb is open until I get to the megohm range. (I think it might be the
20 megohm range to boot.)

Jeff Strickland

"SnoMan" <admin@snoman.com> wrote in message
news:amip53d3ma9uk4tqtef0qgu6v1ujp79o1s@4ax.com...
> On Tue, 29 May 2007 19:30:36 -0500, "DougW"
> <post.replies@invalid.address> wrote:
>
>> take an ohmmeter and measure the bulb side of that circuit
>>to make sure it's good and the bulb holder or wires haven't corroded.
>>(there could be a switch somewhere in that circuit also)
>
>
> This is good advise. Verify the circuit from transformer out. I also
> agree that 250 amps



OOPS!

Did I say 250 amps? It's 250 watts.

Jeff Strickland

"SnoMan" <admin@snoman.com> wrote in message
news:amip53d3ma9uk4tqtef0qgu6v1ujp79o1s@4ax.com...
> On Tue, 29 May 2007 19:30:36 -0500, "DougW"
> <post.replies@invalid.address> wrote:
>
>> take an ohmmeter and measure the bulb side of that circuit
>>to make sure it's good and the bulb holder or wires haven't corroded.
>>(there could be a switch somewhere in that circuit also)
>
>
> This is good advise. Verify the circuit from transformer out. I also
> agree that 250 amps



OOPS!

Did I say 250 amps? It's 250 watts.

Jeff Strickland

"SnoMan" <admin@snoman.com> wrote in message
news:amip53d3ma9uk4tqtef0qgu6v1ujp79o1s@4ax.com...
> On Tue, 29 May 2007 19:30:36 -0500, "DougW"
> <post.replies@invalid.address> wrote:
>
>> take an ohmmeter and measure the bulb side of that circuit
>>to make sure it's good and the bulb holder or wires haven't corroded.
>>(there could be a switch somewhere in that circuit also)
>
>
> This is good advise. Verify the circuit from transformer out. I also
> agree that 250 amps



OOPS!

Did I say 250 amps? It's 250 watts.

Jeff Strickland

"SnoMan" <admin@snoman.com> wrote in message
news:amip53d3ma9uk4tqtef0qgu6v1ujp79o1s@4ax.com...
> On Tue, 29 May 2007 19:30:36 -0500, "DougW"
> <post.replies@invalid.address> wrote:
>
>> take an ohmmeter and measure the bulb side of that circuit
>>to make sure it's good and the bulb holder or wires haven't corroded.
>>(there could be a switch somewhere in that circuit also)
>
>
> This is good advise. Verify the circuit from transformer out. I also
> agree that 250 amps



OOPS!

Did I say 250 amps? It's 250 watts.

DougW

Jeff Strickland wrote:

> The lamp has continuity at something like 1.5mohms, which is pretty
> close to being open. I think I measure in at 1mohm.

That depends on the bulb and what temperature it's at.
Open is going to be infinite, but your basic 75W 120V blub
is about 60 Ohms cold. Halogen bulbs are a different aminal.

Just remember for any bulb it's best to keep your fingers off the
glass and use a clean cloth to handle them. Oil on the higher
output bulbs will cause them to fail early.

> I have several meters, the first one lied to me for whatever reason.
> My Fluke 77 says I have 21vAC on the secondary of the original
> transformer and the bulb is open until I get to the megohm range. (I
> think it might be the 20 megohm range to boot.)

I'd be thinking bulb or the wires leading to it.

--
DougW

DougW

Jeff Strickland wrote:

> The lamp has continuity at something like 1.5mohms, which is pretty
> close to being open. I think I measure in at 1mohm.

That depends on the bulb and what temperature it's at.
Open is going to be infinite, but your basic 75W 120V blub
is about 60 Ohms cold. Halogen bulbs are a different aminal.

Just remember for any bulb it's best to keep your fingers off the
glass and use a clean cloth to handle them. Oil on the higher
output bulbs will cause them to fail early.

> I have several meters, the first one lied to me for whatever reason.
> My Fluke 77 says I have 21vAC on the secondary of the original
> transformer and the bulb is open until I get to the megohm range. (I
> think it might be the 20 megohm range to boot.)

I'd be thinking bulb or the wires leading to it.

--
DougW

DougW

Jeff Strickland wrote:

> The lamp has continuity at something like 1.5mohms, which is pretty
> close to being open. I think I measure in at 1mohm.

That depends on the bulb and what temperature it's at.
Open is going to be infinite, but your basic 75W 120V blub
is about 60 Ohms cold. Halogen bulbs are a different aminal.

Just remember for any bulb it's best to keep your fingers off the
glass and use a clean cloth to handle them. Oil on the higher
output bulbs will cause them to fail early.

> I have several meters, the first one lied to me for whatever reason.
> My Fluke 77 says I have 21vAC on the secondary of the original
> transformer and the bulb is open until I get to the megohm range. (I
> think it might be the 20 megohm range to boot.)

I'd be thinking bulb or the wires leading to it.

--
DougW