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Thank you, Waross. I Appreciate.

@Waross. Thank you for the advice. I will look at the voltage drop applicable, but my application is using bars for a length of about 10 feet. I will also precise that it is for a machine (enclosure), and that I was planning on using Flexibars by NVent (Eriflex). Those have insulation. In...

Hello, Would anyone have an idea from which distance should derating be applied to busbars run in parallel? My application is at 480V and busbars would be on their edge, one per phase, and sized for about 900A (that is over the FLA by a factor of 1.25 already). Thank you.

I had seen these tables, but the distances were a far cry from the NEC's in Table 408.56, and with cause: they are related to section 36, High Voltage Installations. I am specifically looking for 600V clearances (or under 1000V). Should have been more specific about it. :)

Hello, I am trying to find an Canadian code equivalent to the table for minimum spacings found in NEC 408.56. Can anyone point me to the article that would treat of this subject? Thank you.

Hello, For a given kVA size (~2000kVA), 480V output and other similar insulation characteristics (BIL for example), how much larger could a dry-type 13.2 kV transformer be over a 4.16 kV? Thank you!

When it comes to crimping open type contacts and ferrules, is the shape of the tool critical? I see that TE, Altiv, Cinch and other manufacturers have these contacts and seemingly an associated crimping tool. Sometimes, those tools are extremely expensive, making their purchase prohibitive for...

Hello, I have a machine in an enclosure with multiple doors and bolted panels. The machine itself has a 25A three-phase 480VAC fused disconnect, for driving two motors of respectively 1 and 5 HP. At the core of the machine is a gas turbine. I'm actually pushing for having all doors and...

Waross: The cost is obviously going to have some influence on the final decision, but not much. As mentioned initially, the motor is specific, can work on 480V (at VFD input), but can questionably be used with a 600V VFD line feed. Sine wave filter is there already with 480V systems, to be...

Thank you all for your inputs. The application is in Canada, so 600VAC is the norm here. The idea is to simplify the design and hopefully be able to get rid of the autotransformer, so any use of other hardware like a converter is not ideal nor the goal here, I would just have as much...

Thanks Waross for responding. I indeed possibly need to push for the specs the motor designer has given to the wire supplier. The answer probably lies there. On the other hand, the idea behind my post is exactly to avoid using autotransformers. This is the solution we have currently, but it...

How do motor manufacturers do to obtain a given class of insulation? I am mostly interested in knowing if a motor that I know runs very well with a 480V rated VFD (supplied with the same line voltage), can run well with 600V as the line voltage at the VFD. Obviously, the VFD would be rated for...

Hello, Would anyone be able to point me towards which NEMA standard should a permanent magnet synchronous motor be built according to? What info should appear on the nameplate of such a motor? Same as for induction? These motors of foreign fabrication are used in a packaged unit. The motors...

Can anyone help me shed some light on the following claim found in CSA 22.2 No. 14 (2008) paragraph 4.15.2 regarding MOV's as overvoltage protection devices? Where does it come from? Surge suppressors of the metal oxide varistor type are not considered to be acceptable overvoltage protection...

Thanks Jraef for your feedback. I have the same concern for MV close to operable equipment. That doesn't mean that it is not achievable though, as pointed out by Bill. To be investigated further. As for your suggestions, let me give you some background of where I'm coming from. The PMSM is...

Waross, done, already have quotes for core and coil transformers to put into the enclosure. But they are not designing my machine. We asked about cooling and connections, but as far as the safety around our enclosure goes and how this is operated (installed even), they do not care. That's...

Hi, I'm looking for some guidance on how to integrate a MV/LV transformer in a machine. Looking for MV machines on the web, well, only MV motors pop up. If you search for MV equipment with embedded MV transformer, you invariably hit switchgear apparatus. What I have is a packaged machine...

Hi, I'm trying to validate to which value I should size conductors going to a PMSM. The FLA of this motor will be 304A - and 308V (this is a high speed application, 24 000 RPM, continuous duty). Note that this voltage is developed at the motor which is driven by a VFD receiving 480V, 3 phases...

Jraef, thanks for your feedback, much appreciated. Confirming somehow what I was understanding.

On the interpretation of Article 430 part IV from NEC (Motor Branch-Circuit Short-Circuit and Groud-Fault Protection), I am quite confused by the term "Ground-Fault Protection". While I understand the difference with the other member, "Short-Circuit", I am wondering what the use of fuses brings...