10 July 2014
Electrons, Ain't they Fun?
Got a call the other day from a Minion of a Prominent Businessman (I used to work there, and my business card said ”minion” on it. Really) “JC, what do you know about 320v 3 phase power supplies?”
A bit of rigging and the judicious use of a block and tackle got my jaw off the floor. I know he loves to find the good deals on Ebay, but...”What kind of equipment is this?” “RTU #5”, which means Roof Top Unit, which means HVAC, which means Heating Ventilation and Air Conditioning, which means package unit air conditioner, but you knew that. But 320v 3 phase?
“Email me a pic of the data plate, and I'll get back to you.” Yeppers, the data plate says “208/230 wye”, There's a thing in 3 phase electron wrangling that distinguishes between “Y” (wye) and Delta. TL;DR.
Go out on site to check what's there. There's a fab shop and a design shop, a couple of miles apart. It used to be a unitary locations, and as power was needed I installed more circuits , transformers, all that stuff, plus research, documentations, electrical and mechanical fab...damn I loved that job even though I was not paid anything near what I was worth. Anyway:
Wow! Mains feed for the 480v 3 phase has a disconnect, and another disconnect from the mains feed to the 115vac transformer. I can shut this puppy down without going to the pole! Yay!! Problem still exists, though. 480 is not 230, even if you whittle down the conductors. And adding up 115 1 phase cannot magically transform it to 3 ph (catch the electrical joke there? Shocking, I tell you). But I can still disconnect the 480 without disturbing the 115 that runs the outlets supplying the computers and such Double yay!
I shudder to imagine what the old premis looked like after the firm moved out. I knew that all the industrial shelving, all the old cubicle partitions, all the old light fixtures had been moved out. Used drywall stacked and ready for reuse. Nails and screws all recycled and boxed for re-use. Unused electrons stored in Bell jars. Leftover conditioned air compressed and stored in cylinders. So had all the transformers and load centers I had installed. Palletized, shrinkwrapped, and ready to go.
Now when the average person thinks of a transformer, the image is of something plugged into the wall to charge the cell phone, or, in more industrial settings, the thing that you use to charge car batteries. Big fucker, right? Size of a cinder block! So go into your back yard. See the wires? See that big cylindrical thing with fins on? THAT'S a transformer. If you live in a big apartment complex, it's that big hulking ominously humming mysterious thing near your electrical circuit breaker box. You do know where your breaker box is, don't you?
Sombitch weighs about 500 pounds. About 2 foot deep by 3 foot wide by 3 foot tall. Electrical closet is near the center of the building, and you just can't get a fucking forklift through the hallways. Good thing I'm still up on Pharonic Tech. Even better that someone else took care of that before I showed up, so now I can source a 3phase load center and breakers. After hours of research (shopping) on the intertubenetwebs, I find a decent price 10 minutes drive away. Price is about $400, so I did backup to show Ebay and Amazon prices, mentioned shipping charges and returns policies. Purchase ok'd, zooming off at 16:55 h (having notified the supplier that I was in motion, swoop into the lot at 17:04, tap on employee door AND ARE SERVED. God bless all you dudes at Crawford Electric (CESPO), and I'll bring beer next time. Promise.