Need advice on electrical for new used Bailey kiln - extension cable or no?

[Mark C.]

The ground is  aluminum  for sure but yes the new wires should be copper including the ground.

[neilestrick]

2 hours ago, Msheffield said:

Also, my dad just noted that the wire is actually aluminum but connected to copper fittings, and he was thinking maybe that was a bad combo? I have no idea. But when I get the new wires, should I get copper?

Yes, you need copper. Aluminum is not recommended for kiln circuits.

[Bill Kielb]

10 hours ago, Msheffield said:

the wire is actually aluminum but connected to copper fitting

Yes best case aluminum to copper terminations require regular maintenance and often compound (anti oxidant paste) along with maintenance to ensure the connections remain safe, tight and well connected. If you use compound, they are made specifically for the metal in the wire and termination. Codes usually dictate this specifically. Aluminum wire must also be derated so in the table below #6 wire copper = 55 amps @ 60c terminal rating and #6 Aluminum is derated to carry ONLY 40 amps @ 60c terminal rating.

Aluminum and kilns, strongly discouraged.

Edited September 21 by Bill Kielb

[Msheffield]

On 9/20/2024 at 5:25 PM, Bill Kielb said:

Yes best case aluminum to copper terminations require regular maintenance and often compound (anti oxidant paste) along with maintenance to ensure the connections remain safe, tight and well connected. If you use compound, they are made specifically for the metal in the wire and termination. Codes usually dictate this specifically. Aluminum wire must also be derated so in the table below #6 wire copper = 55 amps @ 60c terminal rating and #6 Aluminum is derated to carry ONLY 40 amps @ 60c terminal rating.

Aluminum and kilns, strongly discouraged.

Very interesting, and good to know. Do you think this might have also led to accelerated corrosion in my brass element connectors? Several times in the past two years I've had to take everything apart and sand it down, because they corrode so quickly. Might also just be climate, but I noticed the same black residue on them as in the outlet. 

[Mark C.]

YES-aluminum needs  specail coatings  like no  nox to prevent corrosion at terminaltion points-look it up. I suggest copper for all kiln use. Feeder wires etc

[Bill Kielb]

53 minutes ago, Msheffield said:

Do you think this might have also led to accelerated corrosion in my brass element

For aluminum to copper or brass it is mostly just a function of the aluminum. Your element connections are brass copper and nichrome (or similar) so a good variety of properties all smashed together. Environment is a significant factor (high humidity.  It may sound silly but larger connections with more mass and area to air cool generally perform better than smaller lighter connections with a smaller heatsink capacity. So temperature is a significant accelerant as well. Often connections in kilns are not cooled well so maybe the top hottest connection corrodes first because of the updraft cooling.

So my observance, environment #1 (hard to control) and keeping the connections as cool as possible definitely helps.

 

Edited Monday at 02:16 AM by Bill Kielb

[Msheffield]

38 minutes ago, Mark C. said:

YES-aluminum needs  specail coatings  like no  nox to prevent corrosion at terminaltion points-look it up. I suggest copper for all kiln use. Feeder wires etc

Well, when I re-wire, I will definitely be using all copper then!

[Msheffield]

30 minutes ago, Bill Kielb said:

For aluminum to copper or brass it is mostly just a function of the aluminum. Your element connections are brass copper and nichrome (or similar) so a good variety of properties all smashed together. Environment is a significant factor (high humidity.  It may sound silly but larger connections with more mass and area to air cool generally perform better than smaller lighter connections with a smaller heatsink capacity. So temperature is a significant accelerant as well. Often connections in kilns are not cooled well so maybe the top hottest connection corrodes first because of the updraft cooling.

So my observance, environment #1 (hard to control) and keeping the connections as cool as possible definitely helps.

 

Hm... would it be worth running a little fan under the wiring box to help it cool faster after firing? 

[Bill Kielb]

1 hour ago, Msheffield said:

Hm... would it be worth running a little fan under the wiring box to help it cool faster after firing? 

It usually helps with the temperature aspect a bunch.  When we have failing main bus equipment often a fan extends the life temporarily until new busses can be fabricated, scheduled and installed. For kilns, leaving the element tale a bit longer to be more in an airstream, or some splices are just larger and a better heatsink and can be a passive solution for those one or two that fail prematurely.

The cooling needs to take place during the firing though, not so much after.

Edited Monday at 04:14 AM by Bill Kielb

[Msheffield]

1 hour ago, Bill Kielb said:

It usually helps with the temperature aspect a buch.  When we have failing main bus equipment often a fan extends the life temporarily until new busses can be fabricated, scheduled and installed. For kilns, leaving the element tale a bit longer to be more in an airstream, or some splices are just larger and a better heatsink and can be a passive solution for those one or two that fail prematurely.

The cooling needs to take place during the firing though, not so much after.

Oh... and I had to cut my tails shorter than I would have liked, so that probably didn't help. I'll look into the fan idea. Thank you for the info