Does anyone know the procedure for waking old Norman gear from ancient slumber?

[williaty]

I'm getting a Norman P800D and P2000D that have been in the used camera shop long enough I'm getting them 90% off the normal used price. I'm acting on the assumption that this means it's been years, possibly a decade, since they've actually been powered on. For a shorter storage period, I'd just plug them in, switch them on, and let them idle for an hour before popping them. With this much, much longer sleep, I don't have any idea how to maximize my chances of NOT blowing them up when the plug them in.

Anyone have a good answer?

 

[gorbas]

Watch out! Never unplug light while power pack in on. Turn it down, dump charge and then unplug.

 

[dpurdy]

I have both 2000 and 800 and have used them massively in the past. In my experience the 2000 is far more problematic than the 800. Let them warm up but not too long. It seems to me they build up explosive power as they sit there powered up... much as a teenage boy with no girlfriend. Last time I let my 2000 sit powered up for half an hour it exploded on me when I triggered the flash.

 

[AgX]

(there was a url link here which no longer exists)
(there was a url link here which no longer exists)

 

[Leigh B]

Let them warm up but not too long.
It seems to me they build up explosive power as they sit there powered up.

Any power pack in good condition can remain powered up unused for days or weeks with no ill effects.
Norman strobes are good professional-grade packs, designed to be left on til the cows come home.

The explosion you mention is very possible. It's caused by bad capacitors in the power pack.
Electrical leakage in the capacitors causes internal moisture to become steam, and pressure builds to a pop.

The correct solution is to install new capacitors.

If a pack has not been powered up for six months or more, it may be possible to re-form the capacitors and restore proper operation. This is a very iffy proposition. It may work with one particular power pack, but not with another identical pack. No way to predict. And you don't know how long the "fix" will last. If you use the pack daily, it should be fine. Left unpowered for weeks, the problem will return.

I strongly suggest having the pack restored (capacitors replaced) by a competent service shop.
This can cost a few 100 dollars, particularly for a large pack.

- Leigh

 

[darkroommike]

Watch out! Never unplug light while power pack in on. Turn it down, dump charge and then unplug.

Good advice for all older units, some automatically dump when you turn the unit off, some also dump when you turn the unit down, but I always pop the open flash button after I shut the unit off, no matter what brand the unit is.

 

[darkroommike]

I have read of several different schemes for rehabilitating old units:

• There's this from Holly Enterprises http://hollyflash.com/flash-faqs/
• Another school proposes that you bring the unit up to full voltage by using an autotransformer
• Then there's the on once a week for a few seconds, then once a day for a few minutes school.

All of these schemes assume one head plugged in at full power setting.

Meh, Normans are good solid professional units (the heads put out less light per watt second than similar Speedotron heads but neither here nor there), Norman is now part of Photo Control which has gobbled up a lot of USA lighting companies but third part support is still very good.

Mine both worked fine first time I plugged them in, both were very used when I got them.

 

[wiltw]

There was a recent thread about old studio strobes not powered up for years. The takeaway from it was a combination of ramping up the supply voltage and brief power-on time, stepping up the voltage and the time progressively unitl the capacitors had 're-foemed'.

(there was a url link here which no longer exists)

Without the voltage ramp up (it takes a variac). I would flip on power for a minute and then turn it off, and let the unit set for a while (without bleeding off power!). The flip it on for two minutes, then off, and let the unit set for a while (without bleeding off power!), Then 4 minutes, then 8 minutes, etc.

One reply said:

To re-form a cap that's not yet failed, apply power for short periods, short enough that the pressure doesn't rise.

The process I use is as follows, done every day at noon for a week.
Power the unit up for one minute, then off and leave it off until the next day.
For the next six days, double the ON time each day, i.e. 2, 4, 8, 15, 30, and 60 minutes.

At the end of the week, the re-form will either be successful or the cap(s) must be replaced.
If at any time the fuse or circuit breaker blows, the cap(s) must be replaced.​

 

[Leigh B]

The failure mode for electrolytic capacitors is well-known, unchanged in over 80 years.

Electrolytics contain moisture. It's an essential part of the chemical design that forms the insulating layer.
If the capacitor sits unpowered for a long time, that insulation degrades.

This allows leakage current to flow through the cap, which generates heat.
The heat causes the moisture to evaporate ("boil") forming steam.

If left with power applied, that steam builds up to the point that the pressure causes an explosion.
Electrolytics have built-in safety vents that are supposed to open to reduce pressure, which don't always work.

The 2-, 4-, 8-minute procedure which I described in another thread (quoted above) is designed to keep the internal pressure below the point that will cause an explosion. When power is applied, the insulating layer starts to rebuild itself, but that requires time. That's why the power is left off for a day, to allow rebuilding.

- Leigh