power uit security

[alexS]

I wonder if anybody knows how to handle power cut doen situations.

I am busy installing a PRS standard in Indonesia, and there it's normal that 1-2 times a week the power is suddenly gone, which off course would end up with a broken milling bit I guess.

Has everyone experience with this?

Any tip is greatly apprechiated

best regards,

Alex

[Acmeaviator]

I popped my breaker the other day and it did not cause any damage. I just shut everything off, rebooted, and restarted the cut file. I also learned not to run my sanding table, dust collector, and Bot at the same time:D

[myxpykalix]

If your power goes off then EVERYTHING would stop prettymuch instantly. I believe there is a setting somewhere that creates a "progress file" (log file?)(for lack of a better description).

I would also get paper and pen and make it a habit on long files to every (X) minutes just jot down the cut lines as you see them so that if you have a power outage, when it comes back on, you can use the GOTO command and go to that line and restart from there instead of starting over from the beginning.
If you have a digital camera it might be a good idea to take a picture of its stopping point so that you can position the tool back close to the ending spot because if you restart it from your Zzero spot you will ruin your material.:eek:

[Gary Campbell]

Alex...
Install a UPS (uninteruptable power supply) on the control computer and monitor. When the power goes out you will get errors and of course the machine will stop. The UPS will allow you to note the file line and position so that a restart can be made fairly easily. Do this soon as possible, depending on battery life in the UPS. You will have to rezero all axes and start over, but this will allow you to have an idea of where in the cutting file the machine was.

[alexS]

All,
Thanks very much for all the hints!
I was indeed thinking of a UPS system, which brings me to another important question.

Whats the actual power consumption of a shopbot?

Any recommandation of an appropriate UPS?


Thanks all again!

Best regards from Indonesia

Alex

[michael_schwartz]

Typically the UPS only powers the control PC, LCD monitor, etc... I spent about $100 on mine.

[alexS]

hmm, does really nobody know about the power consumption of a PRS standard. So you see how spoild we are in the west...

[michael_schwartz]

I run my PRS Standard with PC router on a single 20 amp 120 volt circuit. I can't really comment on the actual amperage that it draws since I have no way of measuring that. A spindle would require a separate 240 volt circuit of an appropriate size.

My control PC is plugged into a separate circuit.

Don't forget the consumption of the dust collector, and or vac hold down as well.

[paul_z]

Alex,

I would recommend that you establish a maintenance schedule. At least monthly (better if weekly) do a check on the nuts and bolts, inspect the dust collection system, … ,and make sure the UPS works. I did not check my UPS and did not know the battery was dead. I lost power at a very bad time and it took hours to recover; if the UPS had been functional, it would have taken just a few minutes.

Some UPSs will perform a self-test each day. That’s fine as long as the self-check doesn’t occur while the bot is being used. If the self-test fails while the bot is in use, you have a problem that would not have happened otherwise.

Paul Z

PS I used a 30KVA (240V 3 phase) UPS on a system that had to run anywhere. It was a maintenance nightmare. We had to buy a complete set of spares ($$$) and train the users how to maintain the UPS. When a “hockey puck” SCR fried due to a lightning strike, they had to make their own torque wrench to get the necessary 600 ft-lb of torque to bolt the new SCR into the heat sink! Did I fail to mention the 25 lead acid batteries wired in series to get up to 200A at 300V?

[rhfurniture]

Ummmm - If you have a ups on your control box and computer and your spindle/router is on a separate circuit, if the power goes down, spindle stops but motion continues, - serious dodo. This logic persuaded me to do without, just let it grind to a halt as and when, then recheck axes before continuing. It may be worth having a ups just on your control computer (not stepper drives) if this helps to accurately maintain last position when power died, though I don't know if this is trust-able.
Of course one way of doing this is to have a laptop with battery as the control computer, though I have been told that laptops driving cnc's is seriously problematic due to power management routines.

My 2p, R.