[Question] Electrical stability

[IanF]

Hi Guys,
We have a problem with our platemaker which is intermittent. We generally can make plates some mornings but never later in the day. The platemaker uses a 1000w UV bulb 8.6A. These bulbs are expensive. Link to bulb specs I tried a computer UPS on it but I don't think this is powerful enough and it didn't work.
So my question is what can I use to get enough power to fire up the bulb any time.

[ians]

You can purchase stabilised power supplies for that size, it is not a ups, it has a transfomer and some electronics to make sure there is a smooth waveform. the more you spend the better the better the stability. Make sure you get some one who knows there stuff other wise it could become a very expensive problem which could cause even more problems. The company (bocal electronics) i used for years has closed down, due to less expensive imported products.

[IanF]

Thanks Ian
I am not an electrical person is an automatic voltage stabiliser the same thing? Would this also help the laser cutter the other day we had to put the power up to 50% when we normally use 20%? It was HOT so maybe the power was weak then

[ians]

You need to find a unit which can supply you with a clean sine wave and stable voltage with no harmonic or other interference. You need to find someone who can do a recording with a good quality power analyser to determine what issues there are in your system, before you just go out and fit something which could cause more problems than you trying fix. You need to be careful, because some of the expensive imported machines have stabilisers built in, with capacitors and other smoothing devices.

I had a similar problem, where the lamps on a printing machine would pop for no apparent reason, you would just hear click, click as the lamps popped, at R1000 per lamp and 10 lamps popping at the same time, gets rather expensive, they got some electrician to fit UPS units, i dont know what the outcome was because when i sent them the quote i never heard from them again. I heard the problem wasnt as bad after i had them moved from one electrical grid to another, which provided a more stable supply.

Funny you should mention laser cutter, they also had issues with their laser cutter, it was also a printing company.

[AndyD]

First thing I'd do is check for the obvious before throwing large amount of money at what could be symptoms of a normal fault. I'd check the impedance of your socket circuits and visually check all the terminations in the subDB's and mainDB. It's not uncommon to find a poor or burned termination causing something like this.

If there's nothing obvious I would put a recorder onto the power and see how low the voltage is dropping. If it's going lower than 210v I would request Eskom to check their network and either balance their load better or make remedial action in whatever way necessary.

[ians]

Ian i just need to verify you are concerned about the power on a particular machine and the laser cutter, has this problem suddenly started or has it been an issue over a period of time?

Do the area lights in your factory flicker and do you computer screens switch off for no apparent reason?

[IanF]

I am concerned about power in general. I just had to replace a power supply on the wide format printer and the tech told me it was caused by under voltage as it was a 110/220v power supply so the low voltage blew it. He replaced it with a 220v power supply, then the printer switched off, after he left, so I bought a R900 UPS plugged that in and no problems yet. He said he recommends a ups for all wide format printers now as one consulting firm he replaced 3 power supplies in one machine then told them to get a ups and no problems. At R2000 wide format power supply I just hope it does the trick.
I am getting a new digital colour printer and have told the supplier the RIP computer must be linked to a UPS as those cost R40k a pop.

[ians]

A ups is not a bad idea provided you use an online unit which will give out a constant voltage and not a switching unit. The online units are normally more expensive, but have built in voltage stabilisers and offer a pure sine wave, the bonus with a ups, even if the power dips for a second or 2 at least it will just keep the voltage consistant as opposed to a voltage regulator or stabiliser which dont have batteries.

I believe if you spend lots on equipment and machinery, you need to make sure you spend a percentage on some form of protection for the power supply. The power in this country is way to unstable and very few people understand what goes on in these modern day machines and how to manage the power which is feeding the plant and what to install to minimise interference.

[AndyD]

A ups is not a bad idea provided you use an online unit

Ferroresonant UPS's are also ideal for isolation and voltage stabalisation.