40+ year old service - how much to replace?

[Ragin Cajun]

We have a couple of service upgrade projects coming up. The buildings are ~40 - 45 years old and the owners want to replace the electric service. They have had the usual problems in getting replacement breakers, adding new ones, etc. and need additional capacity as well.

Replacing the service equipment will be relatively simple. The rub comes in down stream equipment, such as panels, transformers, wiring, etc.

Some of the downstream panels need replacing for the same reasons. Many are flush mounted in corridors, some in "equipment" rooms, etc. We can generally replace the guts and keep the cans.

BUT . . . What about the existing branch wiring/conductors? They are definitely approaching the end of life. Cable manufacturers have quoted 30 - 40 years expected life. Of course, we all know of many sites where the cables are much older and doing just fine.

Replacing the feeders to the down stream panels could be a trick. Getting the old cables out of the existing conduits will be a crap shoot. We had one project where the service cables came out but the conduits were less than 100' and were large enough for the upgraded service. On these projects we have feeders from the service equipment that are 200 - 500 feet long. Just don't see reusing them!

These are community colleges where down time to do work is short. Running new feeders in new conduit is doable but getting in the existing down stream panels would be a trick to say the least!

Then, there is the issue of the wiring for the branch circuits, what about them?


Have any of you run into this? What did you do? The further down stream we go the higher the costs. Where do we stop? We're inclined to stop at down stream panels and leave the branch circuits as the effects of any possible failure would be minor.

What about the 480-120/208V transformers? We're looking at leaving them alone if they "look" ok.

Thanks,

RC

 

[kingpb]

No kidding, the transformers "look" ok? Wow, that's amazing that you can tell the condition just by looking at them!:roll:
Sorry, couldn't resist. Anyway, I would sell them on as much as possible, keeping in mind that being a community college they probably have serious $$$ restraints. If you go in with too much, they may say we can't do this now, and will do nothing.

Are the walls being modified where the brach circuit wiring is?. If so, then it is certainly time to do some replacing. If it is left undisturbed, then maybe relpacing end devices (plugs and switches) might be the best effort now. If there is a cafeteria or kitchen involved you might want to consider a rewire on it since the circuits have probably been used heavily.

Replace guts in panels to make them worthy to me is a must, feeders, I would test them and see what the integrity ends up being, maybe you can get away with only having to replace some. In those case's new conduit is probably best for downtime purposes. Being a community college they probably arn't as concerned with asthetics, so some surface mount will probably be acceptable.

In closing, make sure you keep a log of everything you touch and give the Owner a copy for his records when your done. Becasue from the day you finish, everytime something goes astray, you will be called to come take a look. Without the log as a record you won't know what's warranty, and what's not, and believe me they will think everything is your fault.

 

[zog]

If they are having problems finding replacement breakers and parts they are just looking in the wrong place. THere are 3 options here.

1. Use existing stuff and repair as necessary (Least expensive, least downtime)
2.. Replace existing equipment with reconditioned equipment
3. Replace with new (Most expensive and longest downtime)

There is no way to make the "best" recommendation or even think about pricing without more details. Either way I can help.

 

[bsh]

I just finished a college dorm remodal. Due to costs we replaced everything except the panel and wiring in the apartments, except where required changes due to code (adding AFCI for bedrooms, etc). I would replace ALL wiring devices if possible. A 40 year old receptacle is probably worn out. Don't pick and choose because it will be very difficult to identify what was replaced and what was re-used