Greetings everyone, I have a question regarding a fairly straightforward but odd situation/request that I've not seen in my plant days. The majority of my experience is in plant generation with fairly limited cable lengths and standard configurations.
In short, I have a customer who needs...
Hello,
I was recently brought into a project that involves installing a new piece of electrical equipment into an existing substation. The new equipment (a harmonic filter bank) is being installed on the 24.9kV of the substation. The substation is located at ~7150 feet above sea-level and...
I have a question related to NEC 110.26(C)(2) and an existing electrical MCC room installation. The installation has an MCC with a 1200AF main incoming circuit breaker (CB) that is set at 800AT. The MCC is labeled and rated 1200A but set to trip at 800A. The upstream CB feeding this MCC main...
I have a question regarding a fire pump/motor and associated fire pump controller/auto-transfer switch (ATS) installation at small power generation plant (<40MW). The plant is in the final stages of installation and commissioning has already begun. Note the owner of the plant is not a utility...
Hello,
Have a question about a line-up of medium voltage (MV) switchgear. This is one of longer line-up's of gear I've encountered in my career measuring almost 40' in length. The main bus is rated 15kV, 2000A, 25kA, 3PH-3W and consists of seven (7) feeder breakers from very small generators and...
Hello,
I have a question regarding the NFPA definition of a structure. I know in the 2017 Code the definition of a "Structure" was changed. The definition now states "That which is built or constructed, other than equipment. (CMP-1)". They added the reference to equipment for clarity.
I am...
Hello folks,
I'm an power systems electrical engineer and have a concrete related question. Not sure if this is best posted here in the Civil or in the Structural forum.
I'm working on a new project that involves the installation of two (2) small dry-type transformers rated 1500kVA. Each one...
This is a continuation of a recent thread I started but I decided to post this question separately because I felt like it stood on its own
I am either missing something obvious or misinterrupting the Code in this regard. NEC Figure 310.60(C)(3) for detail 2 (3 electrical ducts) and detail 3 (6...
Hello forum members, please find the attached pic showing a ground riser termination a contractor made to an I-beam. It's understood this ideally would be a cadwelded connection but my question is related to them utilizing the same hole for the conduit strap as they did for the ground cable lug...
Hello,
I have a question related to NEC Table 310.60(C)(77) “Ampacities of Three Single-Insulated Copper Conductors in Underground Electrical Ducts (Three Conductors per Electrical Duct) Based on Ambient Earth Temperature of 20°C (68°F), Electrical Duct Arrangement in Accordance with Figure...
Hello forum members,
It's been a long time since I posted. Took some time away from the industry but I'm back and looking for some guidance. I just ran into something I've never seen before. Project I'm on has a small 3kVA xfmr 3-phase, open-delta, open-delta winding configuration, 240V...
Hello,
I have a follow-up question to a thread I started last week titled "Dry-Type Transformer Secondary Cable Sizing". A colleague and I have engaged in another small debate regarding the actual number of cables per phase that need to be installed on the secondary of the transformer.
In...
Hello,
I’m currently supporting a project involving the replacement of an existing generator excitation system. The upgrade involves the installation of a new excitation xfmr, static excitation equipment (controls and power section), associated power and control cabling, etc. The specific...
I have an electrical application requiring the connection of two flat aluminum surfaces. The connection requires bolting hardware. Ideally the hardware would be aluminum. Unfortunately due to project schedule and availability, aluminum hardware is not available. My choice is to use stainless...
Hello:
I'm not sure if this is the correct forum for this question but I'm assuming those most familiar with ASME codes may be able to provide some guidance. I'm actually an electrical engineer at a combustion turbine (CT) power plant in the southwest part of the country. Recently, some...
I realize this may not be the proper forum to ask these questions but I’m unsure where to turn for help. Although I'm requesting non-technical feedback, I decided to post this on the Corrosion Engineering Forum due to the root cause of the issue.
I’m an employee of a power plant in the desert...
Hello, first time user looking for some guidance. I am stationed at a combined-cycle power plant. An MCC which services our cooling tower experienced a major electrical fault during the start of one of the fan starters. The MCC bucket is no longer usable and needs to be replaced. The following...
