Aluminum conduit supported with steel strut straps and unistrut

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zappy

zappy

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Location
CA.
Will you get a reaction between these different metals, or are these two metals safe to touch. Thank you for your help.
 
zappy said:
yeah, it's a very corrosive environment. Do they make aluminum strut straps and aluminum unistrut?
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Yes they do. If this an area that steel raceways are not suitable why would you consider using steel supporting hardware?

In normal installations steel and aluminum is mixed frequently.
 
curt swartz said:
Yes they do. If this an area that steel raceways are not suitable why would you consider using steel supporting hardware?

In normal installations steel and aluminum is mixed frequently.
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It's an old installation from years ago my boss noticed it. He wants us to change the straps and the unistrut.
 
zappy said:
It's an old installation from years ago my boss noticed it. He wants us to change the straps and the unistrut.
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I guess it was mixed because maybe he ran out of aluminum straps and strut? So you're saying mixing aluminum and steel is done frequently? I can't understand why it would be done. If you running in aluminum, there's a reason.
 
zappy said:
I guess it was mixed because maybe he ran out of aluminum straps and strut? So you're saying mixing aluminum and steel is done frequently? I can't understand why it would be done. If you running in aluminum, there's a reason.
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I did one job that specified aluminum just because the engineer thought the labor would be cheaper.
 
zappy said:
... If you running in aluminum, there's a reason.
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Not necessarily. Sometimes the reason is just 'that's what they had' or 'it was cheaper'. Particularly true of FMC, more than other types conduit. But with FMC aluminum is definitely mixed with steel hardware all the time.
 
zappy said:
I guess it was mixed because maybe he ran out of aluminum straps and strut? So you're saying mixing aluminum and steel is done frequently? I can't understand why it would be done. If you running in aluminum, there's a reason.
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Think about die-cast aluminum fittings, aluminum hubs, steel MC fittings/straps with aluminum MC.

If the existing hardware is in good condition there is no reason to change it. If the hardware is badly corroded then a suitable replacement should be installed.
 
curt swartz said:
Think about die-cast aluminum fittings, aluminum hubs, steel MC fittings/straps with aluminum MC.

If the existing hardware is in good condition there is no reason to change it. If the hardware is badly corroded then a suitable replacement should be installed.
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Die cast fittings are zinc.
 
So all we got a stainless steel strut straps so he wants me to put 10 mil tape. Just give them what they want.
 
Read the last part of 344.14 and then have your boss read it. Al conduit and raceways are regularly in contact with steel in commercial settings.
 
FWIW aluminum with stainless fasteners is standard in the solar industry for array racking exposed to the elements. It even gets listed for grounding. I think someone is overreacting.
 
jaggedben said:
FWIW aluminum with stainless fasteners is standard in the solar industry for array racking exposed to the elements. It even gets listed for grounding. I think someone is overreacting.
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where I work is extremely corrosive in certain areas
 
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