Is an aluminum lug mounted on a pool heater allowed by the NEC?

Harold:

Dissimilar metals? 110.3(b) issue? Not suitable for the enviornment?

I had an issue with lugs used on a large solar panel project here, similar to what I think you are getting at. It took documentation from the lug mfg (OEM) to determine that that particular lug was NOT UL approved for exterior, exposed to the elements.

Also 110.14 Electrical Connections. And 680.9 says loads subdived not to exceed 48 amps & protected not over 60 amps...

John,

I was talking to Susanne on Friday and she also quoted 110.14 as did Mike. I have been failing AL lugs on pool heaters since becoming an AHJ 14 years ago. I called up a leading manufacture of pool equipment and asked them why they put AL lugs on pool heaters when it isn't allowed by the NEC. Their only response to me was that U* (You might be able to guess the letter) allows them to do it. I also called U* and asked them about it and asked them why they list the units with AL and they said that they would have to get back to me. That was 14 years ago and I am still waiting for that call back.

Harold:
Based on your above post did Susan say 'NO, the alum lugs cannot be used'??

Did the manufacturer allude that the heater WITH the Al lug was a fully listed assembly. or were they saying the Al lug is 'listed'??

110.14 Electrical Connections. Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.

Connectors and terminals for conductors more finely
stranded than Class B and Class C stranding as shown in
Chapter 9, Table 10, shall be identified for the specific
conductor class or classes.

Harold, send a note to Jeff and ask him about it.

Jeffrey.Fecteau@ul.com

John,

She said that the Al lug can fail inspection because of sec. 110.14 of the NEC as you have stated above.

Greg,

I will try to shoot off an e-mail today if I get the chance.

However the DCA of NJ stated that the pool manufacture has been told to remove the AL lugs and that they will tell them again.

While I am here, does anyone know if the pool widget is UL approved for above ground pool bonding?

The pool widget is a short (nipple?)piece of metal that goes on the pool skimmer hose and has a regular bonding clamp on it. From the looks of the picture, the clamp looks like it is suitable for direct burial.

Harold:
The ones I have seen are UL marked. The lug appears to have 'DB' stamped.

I think that is to "bond the water". You still need bonding for the pool frame.

Greg,

I know that the pool frame still needs to be bonded, I was just wondering if the widget was UL listed.

That is an interesting question. A copper lug might react with the aluminum frame. Most aluminum lugs use a regular steel screw that does not hold up that well although that is what they use to bond screen cages near a pool.
I ended up buying some 1/4-28 stainless set screws to put in the lugs I replaced the rusted ones with on mine.

Same issue with lugs that were installed on solar racking. Steel screws instead of the spec SS screws. Many!! had to be replaced.