Surge protector or dedicated service?

[Bob Rath]

All...As I await the delivery of my new laser (Trotec 300...45w), I am now thinking about electrical issues. I'm curious how many of you on SMC have a surge protector between the 110v line service and your laser. If you do use a surge protector, any recommendations? Is a surge protector enough or is a dedicated APC type "clean" power supply necessary? Obviously there is a big difference in cost.

As always, Thanks

[Dave Russell Smith]

I put in a dedicated 20amp supply with surge protection

[Ted Owen]

I just KNEW you were going to take the plunge. Now don't go telling Chris this was all my fault.

Congratulations, Bob. When do you get to take delivery?

Best, Ted

[John Noell]

Our power fluctuates too much. So, (one logic board later) I use an APC line conditioner. Less expensive than a UPS and the typical UPS does not filter out highs until they are TOO high.

[Tania Duper]

Most electrical engineers that design these laser systems know about the electrical noise the units will be subjected to, in particular, with installations in commercial buildings that are ridiculously noisy.

Therefore, I'm sure most (all?) lasers will run fine without surge protection as there would already be elements in the circuits to protect against electrical problems. To be sure, you'd have to consult the manufacturer to see if they recommend surge protection.

Re: putting it on its own circuit, sometimes you can't put anything else on that circuit if it's already maxed out. For example, if the unit already draws 19 amps and you plug it into a 20 amp circuit, having even a PC plugged into the same line will throw the breaker every time.

Having a huge breaker is also a problem. For example, if you have a 40 amp breaker and the unit draws around 19 amps, you will fry the unit before it ever triggers the breaker.

The big Epilog 36EXT laser requires a 15 amp circuit minimum, and that should work even with their 120 watt laser. There really isn't enough current to worry about since 20 amp circuits are pretty common in the home. Just watch out you don't plug too many other things into that circuit. Worse case, is you trip the breaker. As long as you don't use a 40 amp breaker (or bigger) you'll be fine.

[Tania Duper]

Our power fluctuates too much. So, (one logic board later) I use an APC line conditioner. Less expensive than a UPS and the typical UPS does not filter out highs until they are TOO high.

I'm not sure if you can blame the logic board failure on unconditioned power. The job of the internal power supply is to condition the power and provide clean, and often different voltage & amps to the components.

It seems to me the board had a bad solder or component and it failed, or wasn't designed by a competent electrical engineer. Regardless, in this case conditioning (or lack of) isn't an issue. If there are any Epilog engineers reading this, I'm sure you'd agree and feel free to chime in.

[Randy Digby]

Bob, I've been responsible for a fair amount of electrical/electronics for a long time in an industrial setting. You don't run a $300,000.00 a month power bill without some electrically sensitive stuff being part of the mix. There is the one given - it's aways the smart and safe answer to have surge protection - and you still may take a hit someday.

We would use isolation transformers on DC drives (up to 800HP) and all sorts of grounding, phase monitors, conditioners, and the list goes on. Most of the time it worked - sometimes it didn't.

That being said, I would suggest you take stock of your electrical service history from what you already know. First, how is power delivered to your home/business (wherever the machine is)? Is it provided through overhead wires or is your service underground. I've lived in two houses served by underground electrical for the last 12 years and can't remember a "brown-out" or a visible power surge (where the ;ights actually get brighter). These things happen when wires get together with other wires, limbs, or the ground. Before we moved to an area with underground service, I can remember noticable variations almost everytime the wind changed directions. If your service is in the air, go for some type of protection.

You can still have all the protection you can think of and have the strangest things happen. Our office in in our residence and on carpeted floor. We try to always work bare footed or wear cotton socks. My wife forgot one day, came in from the outside and walked over to our M40 Gravograph to check a run she had going. She had forgotten to remove her shoes and when she touched the M40, I heard the arc across the room and the machine stopped in mid run. It didn't hurt it but it sure got our attention.

Good luck with your 300. We have had a 100 for six months now and it has been a great addition to our operation. Good luck and have fun...oh, and make some money too!!

[Rodne Gold]

I use 2.5 KVA power regenerators for our lasers , those big boxes that smooth and condition and convert to DC and back to AC ...lots of batteries in em - dunno what they called .. UPS Power invertors?
The reason was cos of banding effects when the power dips and surges - we are in Africa where power delivery is poor - apart from running all sorts of other machines in our building.
I can continue lasering for up to 1/2 an hour if we get a complete power failure with these units , but they werent particularily cheap however.

[Tania Duper]

Aside from huge fluctuations with environments of $300k/month power bills and using inverters or other devices that may not deliver a nice sine wave, yeah you may have problems. But in general, in America, these units aren't drawing enough power to worry about and I'm sure each of the laser manufacturers have taken poor power quality into consideration. Many of the cheap, consumer-based surge protectors & power strips with alleged surge protection aren't going to offer you any real protection and are just great marketing scams.

[Dan Hintz]

Most electrical engineers that design these laser systems know about the electrical noise the units will be subjected to, in particular, with installations in commercial buildings that are ridiculously noisy.

Therefore, I'm sure most (all?) lasers will run fine without surge protection as there would already be elements in the circuits to protect against electrical problems. To be sure, you'd have to consult the manufacturer to see if they recommend surge protection.

Re: putting it on its own circuit, sometimes you can't put anything else on that circuit if it's already maxed out. For example, if the unit already draws 19 amps and you plug it into a 20 amp circuit, having even a PC plugged into the same line will throw the breaker every time.

Having a huge breaker is also a problem. For example, if you have a 40 amp breaker and the unit draws around 19 amps, you will fry the unit before it ever triggers the breaker.

The big Epilog 36EXT laser requires a 15 amp circuit minimum, and that should work even with their 120 watt laser. There really isn't enough current to worry about since 20 amp circuits are pretty common in the home. Just watch out you don't plug too many other things into that circuit. Worse case, is you trip the breaker. As long as you don't use a 40 amp breaker (or bigger) you'll be fine.




I'm not sure if you can blame the logic board failure on unconditioned power. The job of the internal power supply is to condition the power and provide clean, and often different voltage & amps to the components.

It seems to me the board had a bad solder or component and it failed, or wasn't designed by a competent electrical engineer. Regardless, in this case conditioning (or lack of) isn't an issue. If there are any Epilog engineers reading this, I'm sure you'd agree and feel free to chime in.




Aside from huge fluctuations with environments of $300k/month power bills and using inverters or other devices that may not deliver a nice sine wave, yeah you may have problems. But in general, in America, these units aren't drawing enough power to worry about and I'm sure each of the laser manufacturers have taken poor power quality into consideration. Many of the cheap, consumer-based surge protectors & power strips with alleged surge protection aren't going to offer you any real protection and are just great marketing scams.

Tania,

You may want to spend some more time working with lasers in a range of locales before making such statements (I'm an MSEE, though I don't work for Epilog, and I disagree). Even the US-made units are susceptible to power issues, and even in the best of areas power isn't always as clean as it should be. Quite a few here have seen banding issues attributed to sagging/overrun power. While the power supplies are designed with quite a bit of capacitance in them for smoothing, major spikes and sags are out of the spec range for them and therefore they pass it along to the other components... a bad spike can quite easily take out the motherboard.

I'll agree that the engineering behind some of the circuits is lacking to some degree, but overall it's pretty decent. At least the companies appear to have left the difficult design work of power supplies to companies who make it their focus. That said, none of the systems are designed with industrial power grid issues in mind... if your company's grid is shifty, it's up to the facilities engineer to properly protect your equipment, not the equipment manufacturer.

Surge protection does not affect the operation of the machine (and therefore no company is going to suggest against it), but it can certainly help in the right circumstances... a non-direct lightning hit will almost certainly take out a non-protected machine along with quite a bit of other electronics in your house. A good quality inverter, such as what Rodney uses, will produce a clean sine wave and at the proper (and locked) frequency, regardless of external influences. Most of us don't need to go to the extreme of an inverter, but a good surge protector is a practical must, and a line conditioner is a must for more than just a few of us.

[Randy Digby]

Dan, this has nothing to do with the subject matter but something that you would understand and appreciate. We were a 17 mega-watt user fed with 150kv primary with automatic switch-over to a 46kv backup service after a power interruption of about .4 sec. When starting back up from an outage (planned or otherwise) we had to plan what equipment came online first because our plant inbound voltage (480v normally) would rise up to as much as 520v + with no load. We would have to bring on our heavy resistance load equipment first and just hope that the PLC's that ran those would handle the high input voltage. They usually did without problem, but we did use all A-B PLC's - they are expensive but they are reliable.

In the old days we would use large capacitor banks to keep the voltage managable. I never did like manually operating the buss plug switches to cut the capacitor banks in and out.

I'm glad that all I have to switch on now is that little red rocker switch.

[Mike Null]

Surge protection does not affect the operation of the machine (and therefore no company is going to suggest against it), but it can certainly help in the right circumstances... a non-direct lightning hit will almost certainly take out a non-protected machine along with quite a bit of other electronics in your house. A good quality inverter, such as what Rodney uses, will produce a clean sine wave and at the proper (and locked) frequency, regardless of external influences. Most of us don't need to go to the extreme of an inverter, but a good surge protector is a practical must, and a line conditioner is a must for more than just a few of us.

I agree 100%.
We had a lightning strike in the back yard that took out a controller panel and many electronics items including all cordless phones.

We get some severe thunderstorms here and I go so far as to shutdown equipment and unplug my engravers if it appears to be a major storm.

[James Rambo]

The summers in SW Florida are a bear for electrical discharge from the sky. If the storm is violent enough we also unplug our equipment. I have installed lightning and surge arrestors on the panel of the house. We also use a UPS for the computers that has a surge side large enough for the lazer to be plugged in also.

[Richard Rumancik]

Bob, you should have some type of surge suppression installed. What exactly and how much depends on what your power quality is like, your budget, and the risks you would like to take. It's like life insurance or fire insurance - chances are nothing will happen - but do you feel lucky?

The laser systems have very basic protection on the input. The power supply is not really intended to be a filter for bad power or surges. Although the laser system engineers are probably well aware of power quality issues they only put minimum protection into the machines and leave the onus on the customer to supply properly conditioned power.

I would not recommend that anyone install a laser without a minimum surge suppressor. If you don't have a big budget get a high-end computer-grade surge suppressor with at least a 3500 joules rating. Higher if you can find one. It should have 3 MOVs and say L-N, L-G, N-G protection. (line-neutral, line -ground, neutral-ground). (If you are running the laser on 240VAC then you might not be able to find a 240VAC computer-style suppressor, at least in N.A.)

You might consider getting a suppressor installed on the circuit at the power panel. A dedicated circuit is best (no compressors, arc welders etc on the same line.)

My own preference is an industrial quality UPS. Such as what is used for computer centers, telecommunications centers, ISPs, etc. They often have a rack-mount form factor. Often you can get a used one at a good price; install a set of new batteries for a couple hundred dollars and you are all set. My unit has buck/boost to control line voltage. I run it at 240VAC in and the laser on 240 as well. You can't plan on using it when the power goes out, but if you do have a loss of power it should have the capacity to enable a controlled shutdown of the system. You might find a new surplus one for less than $500. Keep in mind you will have to replace batteries every 5 years or so.

You might want to talk to an engineer at the local power utility. They often have someone on staff who will give you free advice as to what is appropriate for your situation. Sometimes they will even attach a monitor to your line and record disturbances for a period. My own local utility was only too happy to give me some suggestions.

[Dan Hintz]

Mike/James,

Having lived in Florida for 20 years, I unplug all major electrical equipment during major electrical storms, even though I now live in Maryland... it's simply not worth it to take the chance.

I have a UPS and surge protector on the computers, but so far have not spent the money to do the same for the laser other than a basic surge protector (though I finally bought the proper tools to measure current draw through the laser). Unplugging is the safest, but not the most expedient or convenient method to prevent damage.




Randy,

Back in high school (?) I visited a manufacturing facility (I think I was shilling for a part-time job for car money) that had a nice cap network in their backyard. The high-up I was talking with had a super-sized window in his office that was about as close to the network fenced area as I was comfortable getting. I was "lucky" enough to be there during a misty morning when they needed to raise the breaker bar. F-me, but the arc created as that bar swung away was freakishly large and powerful. Maybe that's why I never did better than a C+ when it came to power classes in school... high-power amazes and scares me at the same time, I never want to go near it.