Wire Sizing for Nyle L200 Kiln

[Warren]

Any EE's out there ?

I am getting ready to set and wire my Nyle L200 kiln.  Per the instructions, I need a 40 amp sub panel at the kiln to feed the compressor, controller and fans.  The feed cable will run about 80 cable feet from the current service panel to the new sub panel. 

What wire size is appropriate to carry a 40 amp load across 80 cable feet without significant voltage drop to affect the equipment ?  As best I can tell from internet search, it will need to be somewhere between 6 AWG and 10 AWG.

Three requirements:  (1) Absolute safety, (2)no potential for equipment damage due to voltage sags,  (3) least cost option witout violating first two requirements.

Warren

[Lance in Ontario]

Warren
I am into the same questions you are .I was told to use a #3 awg but I am going 250' I was told to go big enough to run lights and anything else I might need . I am still waiting on a price, which is going to be scary.I was also wondering if an inline surge protecter would be a good investment. If I find out any more I will let you know
Lance

[scsmith42]

Warren, I'm not a double E, so you can take this with a grain of salt, but according to my Pocket Reference, for a 40 amp load, 2% maximum voltage drop, 80' run, you would need to use a minimum of #4 wire if the load was 120VAC, and #8 wire for 240VAC.  As I recall, the kiln compressor runs on 240VAC, but I don't recall what the recirculating fans operate on.

If it were me, based upon your three criteria I'd plan on using #6; that way you'll have some spare capacity in case you opt to install additional fans, lights, etc in the future.  If the fans are 120VAC be sure to put their breakers on separate legs of the service in your panel.

Regarding Lance's recommendation for a surge protector - I highly recommend one.  My Nyle L200 (Woodmizer 4000) has a very sensitive electronic controller, and I lost two of the individual electronic controls ($400 bucks each) before I installed a surge protector in-line.  No problems since then.  I found the surge-protector on e-bay from an electrical supply house that was selling old inventory.  Think that I paid about 40 bucks for it, and in hindsight wish that I'd spent that money up front...

Scott

[Norm]

I agree with Scott on the #6. Compressors use a lot of juice on start up so I'd go with it and be able to add a couple of small circuits in the future if needed. Even better than surge protectors is to use a UPS system. Good ones do a great job of protection and keep from having to reset things after loss of power.

[Lance in Ontario]

Norm
What is an UPS system and how does it work? Can i put it on my main panel in my house so I can protect it and my kiln?

[Norm]

Lance a UPS system is a uninterruptible power supply. Most are a gel cell battery that is always charging and senses when power goes out, it then runs off the battery. The good ones have very good filtering but are not meant for heavy loads. After you get above 1500 watts they get pretty pricey. I would use one only for the kiln control itself not for the fans or the compressor.

[Don_Lewis]

The system Full Load Amps is just over 30 amps, enough over that we don't recommend a 30 amp fuse or breaker. #8 is ample. #10 actually would be okay. Depends on grade of wired, buried or in air etc. But #8 is conservative

[Warren]

Thanks everyone for your input.  I will probably go with #8 as a middle of the road solution.  I had not thought about surge arrestors or UPS systems,  But, I can see where they would be beneficial.  I will need to scratch my head on that for a little bit. 

Again, Thank you,

Warren