Adam Stouffer wrote:
We're trying to troubleshoot an ancient power supply for a high pressure
mercury arc lamp. Theres a SOLA transformer that feeds into a rectifier
stack and then two large filter caps. The output from the filter caps is
only 60 vdc while they are rated for 150 wvdc. Every SOLA I've seen had
a 115 vac regulated output. Theres no specs except for the SOLA part
number "21-877". Do they all output 115 vac or were there lower voltage
models? My guess is that the oil capacitor has gone bad and its no
longer regulating correctly. Any thoughts?

Could be, stick it on a bridge and see. Is it leaking?

It may not have a 115vac regulated output. Some of the Sola
transformers were step-up or step-down. A call to Sola should identify
the part number. I have seen some with 24VAC secondaries.

Is the thing rated for 60cycle use? A 50 cycle ferroresonant transformer
will go berserk on 60 cycle power.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:

Could be, stick it on a bridge and see. Is it leaking?

Not physically Tomorrow I'll do some testing.


It may not have a 115vac regulated output. Some of the Sola
transformers were step-up or step-down. A call to Sola should identify
the part number. I have seen some with 24VAC secondaries.

I tried calling them but the guy basically laughed and told me good
luck. My understanding is its the Sola name but owned by a different
company. I tried searching to see if anyone had scans of an old catalog
but no luck.


Is the thing rated for 60cycle use? A 50 cycle ferroresonant transformer
will go berserk on 60 cycle power.
--scott


Its definitely 60 cycle. The supply runs a "super pressure" mercury arc
lamp for an optical comparator. Up until yesterday its had regular use
for years but now the lamp will not sustain an arc. The only problem
that stands out is seeing 60 volts on the caps rated for 150. Thanks for
the quick reply.


Adam

Adam Stouffer wrote:

Its definitely 60 cycle. The supply runs a "super pressure" mercury arc
lamp for an optical comparator. Up until yesterday its had regular use
for years but now the lamp will not sustain an arc. The only problem
that stands out is seeing 60 volts on the caps rated for 150. Thanks for
the quick reply.

Get the data sheet for the arc lamp itself and see what voltages it is
supposed to have for starting and running. Then work back from there.

If I saw a low voltage on the supply filter caps I would check the
rectifiers before anything else.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(Scott Dorsey) writes:

Adam Stouffer wrote:

Its definitely 60 cycle. The supply runs a "super pressure" mercury arc
lamp for an optical comparator. Up until yesterday its had regular use
for years but now the lamp will not sustain an arc. The only problem
that stands out is seeing 60 volts on the caps rated for 150. Thanks for
the quick reply.

Get the data sheet for the arc lamp itself and see what voltages it is
supposed to have for starting and running. Then work back from there.

If I saw a low voltage on the supply filter caps I would check the
rectifiers before anything else.
--scott

It appears to me that OP seems to think that BECAUSE the caps are rated
for 150WVDC that 60V is "abnormal". 150% over-rate on caps is not even
noteworthy.