Aloha all, I am going to build a 48V LFP battery pack to power a John Deere Gator that had about a half ton of lead acid batteries for energy storage. I need 400 Amps output (short time) from the battery. I would like to build a battery using sixteen 280 or 304 Ah prismatic LFP cells. I don't...
Ok thanks. Found a 30V 10A chinese made power supply on Amazon, have it on order. I'll get over there after Christmas and do some more testing. I really appreciate all the help guys! Aloha and Mele Kilikimaka (Merry Christmas)!
Keith
K2ofKeyLargo but now Hawai'i
Ok, great. I have a lot of things to check. I will need to aquire a DC power supply - don't have one since I left the electronics business, but as I've come across the need for one several times, it is a good time to get one. What would the typical field winding current and voltage be for...
Thank you all for the ideas and suggestions.
I can do some further checks, we'll have to disassemble and hunt for these connections. We don't have a wiring diagram for the generator, and I've not done any work on generators in the past, but I'll certainly dig into this. Nothing on the AVR is...
Here's more info and a full scope trace - Output of the generator is 120/240V single phase. The scope traces were taken with NO LOAD, but we connected a resistance heater to the generator and the trace had the same distorted waveform. The scope was just connected across the 240V output...
A friend has a Chinese made 24kW diesel pm 60 Hz 3 phase generator wired for single phase output (zig-zag I think). He is off grid here in Hawaii, and has used it for backup to his PV system occasionally. After he burnt up a few appliances, we looked at the output on my oscilloscope and found...
thanks BlownUp. I did some additional searching, and found nothing more in NESC. NESC 110.A.1 says: "to form an enclosure as to limit the likelihood of entrance of unauthorized persons or interference by them with equipment inside." I think this is the only wording that implies "don't let...
Is there anywhere in NESC that requires clearances be maintained (trees, structures etc) that would aid a person in climbing over the fence? I can't find this wording, although I thought it was in there somewhere.
K2ofKeyLargo
I consider the wording to be vague in the USA NESC 2012 regarding depth that high voltage cable must be buried. A minimum depth is NOT stated, even though Table 352-1 does give depths. The rule that references Table 352-1 is 252D2, which states "Burial depths as indicated in Table 352-1 are...
Are there any websites for selling excess electric utility inventory? I'd like to find a place to post what we have to offer to other utilities, not a middleman.
K2ofKeyLargo
I am an electric utility engineer. On a 20 mile long 25kV distribution feeder, 336.4kcmil AAC Tulip phase conductor with a 7#8 Alumaweld neutral, peak load about 9MW around 200A/phase. We are having trouble with voltage unbalance. Eighteen miles out on the feeder we have a set of three single...
transmissiontowers - So how do you calculate the "engineered fall distance" from a structure? I am an electric utility engineer, and I just had a designer for a new HUD residential project in my office asking for this info. I have a 138kV line with three single pole steel structures, and a...
Hmmm... I don't remember off hand how I've chosen insulators, but I'd say that all the flash overs should be >= your required BIL. As jghrist points out, BIL isn't always the deciding parameter. On my system, the creep or leakage distance is what has always been the ruling factor - if I have...
Sounds like the input to the transformer could be unbalanced. 260V is too hi - 252V is what you should see max.
I don't think overvoltage would cause flicker though. And the bubbling transformer sounds like a third problem.
K2ofKeyLargo
You can if the output of the transformer is radial (no other possible sources to parallel). Marmite is correct, there are other things to consider that should be looked at - a wiring diagram would be very helpful to let others see what you are considering.
K2ofKeyLargo
Lefty,
What do they mean by "disconnecting means intergral with the luminaire"? This sounds to me that a switch has to be integrated, that is, a part of, the luminaire. This doesn't sound practical, so I must be interpreting it incorrectly.
K2ofKeyLargo
I would suggest adding mechanical supports, as bradh01 says. The mechanical supports we have supplied with our large transformers are fiberglass bars that bolt onto the bushing and onto the tank, holding the secondary bushings fairly rigid. You probably can devise another method to hold the...
When installing a bank of utility transformers, say 100kVA 25kv:277/480V, using three single phase transformers, what effect does unmatched impedance have on the operation of the bank? If one transformer is 2.0% and the other two are 1.6% for example, what will this do?
K2ofKeyLargo
Why do open delta banks not regulate as well? How do you calculate the limits on loading on an open delta bank? Anyone recommend a good reference book that discusses open delta transformers?
K2ofKeyLargo
I would contact S&C Electric Co. or Kearney (Fayetteville, Arkansas) and I'm sure they can supply you with fuses that will cross reference.
K2ofKeyLargo
