So as everyone know, lead times for certain equipment is a big problem.
We are getting ready to start a large temp power job( we got last minute notice).
Out temp power distribution setups are high voltage(277/480) panelboard, xfrmr, low voltage panelboard.
The sizes are 200A, 250A and 800A on the 277/480v side.
The lead times on the large MCB's are very long.
IS there another setup/design that would achieve us serving branch temp loads, about (6) 1P & 3P 20-50A in each temp panel without needing the larger MCB.
I don't see it as you obviously need OCPD. Even disconnect switches are 14-16 weeks out.
Thanks .
High voltage is defined as 36 kV up to I think around 100 kV and it’s called EHV after that internationally. NEC weirdly calls high voltage anything above 600 V. 480 is low voltage. So stop using incorrect terms if you intend on getting any kind of respect from vendors. Saying 480 is high voltage just marks you as not a serious buyer.
As far as “hard to come by” often you just have to educate your customer. First, this is August. We are at the middle of the construction season. ALL lead times stretch out to 12-16 weeks or more by now. Even in “normal” years (whatever that means) lead times shrink in November, hit their lowest in 1Q, and start growing in March or April. This is the capital budget season. Corporate budgets reset January 1 and it takes 1-3 months for projects to roll out of engineering plus you have winter in the North to contend with. State budgets often reset July 1 and the Feds reset October 1, so the cycle continues right up until the double holiday silly season when everyone tries to spend every remaining dime but manufacturers are all on vacation so they break every delivery promise they make. Not being harsh here. Often you have to educate your customers who are simply unaware that pretty much all distribution equipment is made to order.
I’ve done this stuff for YEARS at all levels including actual high voltage equipment (69 kV) and even EHV. Frequently customers come to where I work seeking what you are talking about. I swear they all think that you can bug anything you desire off Amazon Prime with 2 day delivery. What they don’t understand is this isn’t a residential panel at Home Depot. If there was a “part number” it would cover a couple pages. Ordering just means you get into a queue at the factory.
If you are talking to Eaton, Schneider, AB, or ABB right now it’s a s-it show at best. Eaton is still recovering from moving their plant and ABB is just a mess with the whole GE/ABB/Hitachi mess. AB buys from ABB. So that leaves Schneider which is having a major recall going on right now. So anything you can do to bypass the “big three” is much more likely to work. Sorry but that’s just reality. Siemens if course is fighting EU COVID issues and war. My contacts at the plants (Mebane, South Boston, Pine Tops) don’t inspire a lot of confidence this will improve soon if the employees don’t have confidence, that’s not a good sign. Smaller players have issues too but are having less issues.
So we need to come up with either less prepackaged solutions or deal with what is available already built.
How about fused disconnects? Aka “safety switches”? They are far more reliable than breakers. There are lots of plants out there running just fine with nothing but fused disconnect systems. They are better as transformer feeders anyway. It’s just a set of troughs with fused disconnects that you can buy from even places like Grainger. It’s simple, cheap, and it works. The only hassle is using say power distribution blocks to connect everything unless you are knowledgeable about bus bars and have portable benders. Lots of plants are built this way. Just please avoid throwing up giant troughs filled with split bolts. One failure with those and you are down for data requiring it. And leave some expansion room.
Second option: bug just breakers. I’m not having a problem getting UL rated breakers suited for panel construction. In other words bolt in. These are 489, not 1077. Know the difference! If you are willing to build an NEC industrial control panel for distribution (DIY) then you can be up and running in a couple days. This is obviously a permanent solution, not temporary. On smaller ones you can buy premade bus bars and bolt in breakers. But that’s not going to work at 800 A. This is pretty much the same idea as the fused disconnects but using breakers. It should be no problem to buy what you need and put it in a box then attach a cover for either 50 kA or 65 kA 600 V rated breakers. I’ve been buying from
Benshaw. They can do it for you but again…lead times are long right now.
Another option if you insist on using the big names is going to a salvage company. Needless to say used may have reliability issues but faced with less reliable equipment or nothing at all it’s an obvious choice. They do test everything but you can’t test everything. Just make sure it’s got a warranty. You may have a couple returns.
So when I get an unreasonable customer first I give them exactly what they want and the lead time. Then I run through a couple options and see where we end up at.
