It may be a bit embarrassed asking this question, but this is where engineering meets real life questions IMO. Is this 200A fuse allowed to be installed in the shown 400A FDS or are fuse reducers required (Eaton Part # J-42)?
We have a vendor who is supplying an integrated motor control cabinet on a piece of equipment. The motor is a 480V, 250HP motor. Down stream of the main CB, the vendor is tapping the power cables between the CB and the 250HP motor contactors to supply 2 small fan motors, a 3HP and a 7.5HP...
Can anyone offer a website or point me in the direction on some estimated costs for 15KV Switchgear costs? We're likely spec 15KV metal-clad outdoor with common BIL and KAIC ratings. Just need to put together a quick high level estimate and don't need to bother vendors at this point. I was...
Thank you all for your support. You guys are all making sense and I agree it's now a single phase system. Now it's up to us to try to get PECO to admit to it. In the end and if it's too much hassle, we may look into a static converter but I'm not sure that'll work as the HVAC likely has both...
Thank you for the support.
FacEngPE - The input voltage were 242,239,237 as expected.
Argotier - Thanks for the diagram. That totally makes sense. Here's a sketch of some of the other values.
The second picture is the wiring diagram that was on the failed unit (original) that worked for years. And yes, it is a 5 wire system. Thank you guys.
EDIT: I assumed it was a 5-wire system, but now that I think about it, I only saw 4 wires in the fuse box, I would have to imagine there is...
We have a customer in Philly who currently has an old 2 Phase system (which history tells me has a phase shift of 90 Deg). These systems used to be popular in Philly and still existing in some areas. For years, the customer had what appears to be a single phase buck-boost transformer to turn...
Thx 7anoter4. I appreciate it. I didn't know if there was an easy way for not. Open cover might be an idea, just worried about truck traffic and dirt as this is a dirt road. The only way I think the correct de-rating factor might be able to be calculated would be via the SKM module or...
Thanks 7anoter4. But Table 310.15(B)(3)(a) is required to be taken into account, as all references in the NFPA 70 for conductor ampacities for 1/C or 3/C. This is why the table is entitled "...More Than 3..." Since there 4 current carrying conductors we need to de-rate the cable by at least...
Per the sketch below, can someone confirm these cables only need a 0.80 de-rating factor (Table 310.15(B)(3)(a) since there are 4 carrying conductors per cable (DC application, 2-1500V+ and 2-1500V -) as long as 1" cable diameters are spaced at 1" intervals via intermittent plastic cable...
Thx dpc. I knew it was more expensive, but never thought 10x, although I can understand why. It's also likely based off of distance. I'm basically looking at a small 200 foot run and the client is looking for a price to go U/G. More of a cosmetic decision.
