Electrical panel : Ground/Neutral bus bar question

I would never replace copper with aluminum. Aluminum is less conductive and tends to expand/shrink as it heats/cools from current. My previous home had aluminum wiring and it was a pain in the a$$.

May be, it wasn't clear but I am trying to replace Aluminum Ground/Neutral bar with Copper and I am finding hard to match mounting holes etc. My question is, can I buy ILSCO N174 ( or alike) and drill hole ( at wire hole) to match with mounting position at panel ? Is it worth the effort ? The main bus on my panel is Silver plated Copper.

Thanks

Diwakarv,

How will you electrically/mechanically connect the copper neutral/ground bar to the existing AL, aluminum, bus that feeds the panel from the meter socket? If the AL bus is not made of high strength 6061-T6 aluminum alloy you cannot mechanically bolt the copper neutral/ground bar directly to the AL bus. Even if you were to use an anti-oxidation paste between the two metals, given time the copper will burn itself free from the AL bus.

As for the neutral/ground bars in the CH panel they are not made of regular AL. If they were you could not terminate copper wire to them. They are made from 6061-T6 aluminum alloy and are dual rated for use with copper and aluminum conductors. More than likely they are also electro-tin plated.

Food for thought, the CH 200 amp main breaker in the panel has mechanical lugs made of 6061-T6 aluminum alloy.

Here are a couple of manufacture examples.

Link

Link

I would not mess with the factory installed neutral/ground bar found in the CH Load Center electrical panel. First it will void the UL/CSA assembly listing as well as the manufacture warranty.

If for some reason the electrical connection of your copper neutral/ground bar to the AL bus that is fed from the source utility transformer was broken, became open, the unbalanced 120V load from L1 to source neutral and 120V load from L2 to source neutral could not return to the source on the service neutral. The unbalanced load would then become part of the L1 to L2 series balanced load circuit. That's not good!

Here are a couple of nice videos on the subject.

Link
For this one it would have been nice if the guy would have first used two 120V bulbs of the same wattage. Then when he broke the main neutral connection, thus putting the two bulbs in series with one another, he could have measured the voltage across each lamp and showed the voltage across each bulb around 120V.

After the above example I would of then liked him to change out one of the bulbs to the higher wattage bulb. Then measure the voltage across each lamp again. With this example he would have measured a lower than the normal 120V across the higher wattage lamp load, and a higher than normal 120V across the lower wattage lamp load.

In this video the guy does a little better job.
Link

Thing to remember, only the unbalanced load returns on the main service neutral back to the source. The balanced 120V loads of L1 to neutral and 120V loads of L2 to neutral are in series with one another. It the nature of how a split phase secondary winding of a transformer works.
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Jim

Hi Jim,
It is always educational to read your response. I takes me an hour to read/understand your post and additional couple of hours to reply :-) I surely appreciate your feedback.

CH panel CMBE4242B200BTS uses part no. N-8108-86 , catalog no. NBAE-0924-2 , which tin plated aluminum (6061-T6) for ground/neutral bar.
http://www.ilsco.com/documents/PDF/TechnicalDrawing/N8108.pdf.
I still don't know the whether the bus is AL or 6061-T6.

"Food for thought, the CH 200 amp main breaker in the panel has mechanical lugs made of 6061-T6 aluminum alloy"

I didn't know that, thanks for info.

It seems , my goal of having a all copper panel is unrealistic. Every panel ( including QO) uses 6061-T6 extensively, this alloy is 43-45% conductive compared to copper.