Replacing HVAC equipment with like for like - Reuse OCPD’S?

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designer82

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I have a project where a lot of HVAC equipment (Condensers, air cooled chillers, VRF heat pumps) are being replaced with new like for like models.

Is the standard protocol to replace the disconnects with new or re-use existing?

As I read back the question to myself, I would say all new disconnects as these are likely provided by the HVAC contractor anyway brand new but it’s always good to confirm.

Thanks and I appreciate it
 
You don't say what the age difference is but I find it hard to believe that many OCPDs would not have to be changed as they would likely not match new equipment. Same for MCA.
 
zbang said:
If the existing disconnects, and even conduits and conductors, are fit-to-purpose and in decent condition, I can't see any reason to replace them. And once you start simply replacing things up the line... how far do you go?
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Agreed. Unless someone is paying for them to be replaced, why?
 
zbang said:
If the existing disconnects, and even conduits and conductors, are fit-to-purpose and in decent condition, I can't see any reason to replace them.
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This. No reason to replace equipment in good shape.

On the other hand, the HVAC equipment is being replaced for some reason. If there is some damaging environmental condition then perhaps the electrical hardware has been similarly affected.

On the other hand, if good condition equipment is being replaced for performance or efficiency reasons, perhaps the electrical hardware is in perfect sh as pe.

Jon
 
zbang said:
If the existing disconnects, and even conduits and conductors, are fit-to-purpose and in decent condition, I can't see any reason to replace them. And once you start simply replacing things up the line... how far do you go?
Click to expand...
If bad things happen and you end up in court, the lawyers might argue Proximate Cause and the Reasonable Person standard.

Offhand, I'd say the CBs that are likely to trip more often are more likely to have used up their useful life.
I'll take my chances with the CBs upstream that never trip because their contacts were welded shut a long time ago.
A middle ground might be to test someways up the chain by using a heavy overload for a second or so. It shows Due Diligence and a Duty of Care.

On the other hand, this costs time. The "project iron triangle" says you can't minimize cost, maximize quality and maximize production/throughput all at the same time.


Here's one on Proximate Cause.
A train passenger was killed by the flying foot of a person who successfully killed himself by stepping in front of the train.

Who's liable for wrongful death?
 
I did say fit-to-purpose and in decent condition. That implies some amount of inspection and thought ("Hmm, this is a 50HP disconnect and in good condition, I only need 40, we'll keep it." or "Needs 6 gauge and 4 is already run to the roof. That's OK but let's megger it to be sure.") It's called "due diligence".
 
designer82 said:
I have a project where a lot of HVAC equipment (Condensers, air cooled chillers, VRF heat pumps) are being replaced with new like for like models.

Is the standard protocol to replace the disconnects with new or re-use existing?

As I read back the question to myself, I would say all new disconnects as these are likely provided by the HVAC contractor anyway brand new but it’s always good to confirm.

Thanks and I appreciate it
Click to expand...
Unless the disconnect switch is corroded as Winnie stated I see no reason to change them. An AC unit lasts about what 20 years? The disconnect switch which is hardly ever used should last at least the life cycle of two AC units.
 
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