Epilog Helix 75 Watt 120v vs. 220v?

[Bruce Clumpner]

I just picked up a used 75 watt Helix and someone on the epilog facebook page suggested running it on 220Volt. He said the higher current gave better performance. I've found my mini 40 performs well enough on 120, with a fairly low amp draw.

Anyone have experience with this and can explain the benefits before I call tech support or re-wire the garage?

TIA

[Kev Williams]

I may be wrong here (like that's a stretch)--

-but it seems most lasers and their innards are set up to run on 110 or 220 volts, and that being the case, I would think that they simply run on 110v, and if plugged into a 220 source the second leg is shunted or ignored or whatever. The laser's power supply powers the tube with lower than line voltage (my LS900 is supplied 35 volts), so I'm not sure if the power supply's have a provision to work with a full 220v, or even if they need to...

Just conjecture

[Glen Monaghan]

I initially had a 40 watt mini in a bedroom with the exhaust fan (sitting in a window adapter I made, much like a window AC unit) and overhead lights on the same circuit. I never blew a breaker or noticed any change in the exhaust fan's scream, but the overhead light dimmed and pulsed in time with the laser firing. When I ran an extension cord from another circuit to power the blower, the light didn't dim so much but still was noticeably affected by the laser's operation. When I finally built my new studio, the laser, exhaust, and lights are all on separate circuits, with two additional circuits in the room for computers and everything else.

I'm pretty sure that a 75 watt Helix will basically max out a normal 15A 110VAC breaker (the 75W of the tube is only a small part of the overall Helix power requirements!), and you definitely don't want to put any other significant load on that circuit. A 220VAC circuit would be advisable, just as it would be advisable for any high power tool (like a big table saw). You don't want go to 220VAC because "higher current g[ives] better performance" but because the doubled voltage allows you to cut the current by approximately half (over simplified, power = current * voltage so doubling the voltage halves the current required). Consequently, instead of stressing a 15A 110VAC breaker by running it at capacity, you'd only be using about half the capacity of a 15A 220VAC breaker which provides better long term reliability and safety.

[Lee DeRaud]

I'm pretty sure that a 75 watt Helix will basically max out a normal 15A 110VAC breaker (the 75W of the tube is only a small part of the overall Helix power requirements!), and you definitely don't want to put any other significant load on that circuit.

FWIW: http://support.epiloglaser.com/artic...-Laser-Wattage
The 75W machines use a 1200W power supply. Those typically run at 85%-90% efficiency at maximum current draw, so figure something in the 1400W input range or 12.5A-13A maximum. Most engineers tend to be a bit conservative when it comes to power-supply sizing, so I'd be surprised if it ever gets that high.
(Note that Epilog calls out a minimum 15A circuit requirement for all machines: the machines with larger power supplies are 220V-only.)

[Bill George]

What Lee said, and the reason why they have both 240/120 volt machines. Most of the overseas market uses the 240 volt in the common wall outlets. Not all, but enough to make you think when you go on a trip about taking power adapters along.

[Glen Monaghan]

While a 15A 120VAC breaker should allow up to 1800W, typical continuous duty rating is 80% of the max or 12A and 1440W. So the 1200W power supply, according to Lee's reckoning, could exceed the recommended 80% threshold for continuous operation. The problem is worse if typical wire gauge is used and it's a long-ish run from the panel to the machine because the wire itself becomes significant (pretty sure that was why my overhead light pulsed in time with the laser). Probably wouldn't trip the breaker/blow the fuse, but you really should ensure there is nothing else on the circuit with that machine.

[Lee DeRaud]

While a 15A 120VAC breaker should allow up to 1800W, typical continuous duty rating is 80% of the max or 12A and 1440W. So the 1200W power supply, according to Lee's reckoning, could exceed the recommended 80% threshold for continuous operation. The problem is worse if typical wire gauge is used and it's a long-ish run from the panel to the machine because the wire itself becomes significant (pretty sure that was why my overhead light pulsed in time with the laser). Probably wouldn't trip the breaker/blow the fuse, but you really should ensure there is nothing else on the circuit with that machine.

I didn't catch this when I read it in your previous post...you have an overhead light on the same circuit as wall sockets?!? My 40-year-old house doesn't do that: even the switched sockets are on a "light" circuit rather than a "socket" circuit. Not to mention that the plug circuits are 20A vs the 15A of lighting circuits.

(In any case your 40W Mini only has a 600W supply, half what we're discussing here.)