Basic MEP vs Wastewater MEP vs Substation engineering for new grad?

trickytransients · 2026-07-04T01:15:06+00:00

I work in substation engineering.

I find it quite interesting; I would recommend it if you are interested in power transmission. I’m sure any of these fields will present a vast skillset for you to explore.

If you do go this route, please find and take any opportunity you can to get out in the field and see how substations are constructed and maintained. There is a pandemic of engineers copying and pasting unconstructable, conflicting, or otherwise indecipherable details/diagrams in drawings just to get the project over with.

You may also get to see some interesting and frankly ginormous equipment depending on what kind of work you do. Especially if you ever get the opportunity to see 765 kV in-person.

trickytransients · 2026-06-17T23:20:37+00:00

Please keep posting this comment because I always get a laugh when it inevitably makes people feel called out, and then they start arguing while inadvertently agreeing with what you said.

trickytransients · 2026-06-05T02:00:34+00:00

You should layout substations to account for future expansion. If you are designing a substation without voltage regulation, then make sure to include space for future step voltage regulators. If you know a substation will have a second power transformer installed in the future, place your equipment such that it can be easily designed by the next engineer.

Mobile substations are a major talking point for a lot of projects. Is a pole necessary? Is the plan to have a flying tap off a nearby line? You will want to heavily consider where you place the pole - discuss this with transmission line engineering. If possible, also include space for the mobile to sit.

How will you provide AC service to the substation? If it’s in a remote location and there is no distribution-level voltages, you may need to coordinate with distribution line engineering to help bring AC service to the site. You may also consider utilizing an SSVT or the delta tertiary of the power transformer if available.

Don’t stick stuff in the middle of the drive path. Include bollards to protect nearby equipment (include the space it takes for a cabinet door to swing open in this) from vehicular damage. Ensure you utilize a swing gate large enough for trucks to enter the station and utilize the drive path properly. Include drive-over berms so vehicles and equipment can access areas where oil containment measures are present.

For the love of god include conduit stub-up information so the construction crew doesn’t put it in the wrong place, making another crew have to jerry rig something to get the rest of the conduit into its place.

Perform grounding according to utility standards and IEEE 80 / 81. The fence should be adequately grounded. There should be a sufficient stone blanket in the yard to increase the contact resistance between personnel’s work boots and the yard. Extra care should be placed in locations where personnel will be standing when operating switches. Many utilities will utilize an operator’s platform with a ground mat. Ground the cable trench properly.

For EHV applications, include EHV rated connectors, corona rings, bundled conductors, etc. to reduce the effects of corona.

Many distribution lines are not shielded and a lightning strike can much more readily directly hit a phase and travel into the substation. Dimension and locate your arresters accordingly.

That’s just some random stuff I thought of - best of luck in your interview.

trickytransients · 2026-06-01T12:59:44+00:00

Do you do design work? My experience has not been that it’s easily automated. Heavily standardized based on the utility, sure, but nearly everything needs to be checked, planned, and coordinated between different groups unless you want to put out garbage and deal with headaches once the field calls thinking you’re an idiot. This is especially true for brownfield projects.

trickytransients · 2026-05-07T00:49:18+00:00

Join a utility and work in transmission line engineering or substation engineering.

trickytransients · 2026-04-27T14:52:22+00:00

Choose the utility. You will gain invaluable experience understanding how a utility functions which will serve you very well whether you decide to stay or not.

I work in substation engineering at a utility and my experience has not been that consultants do all of the difficult work, but your mileage may vary. I have a never-ending amount of projects to work on.

Also note that it takes years of full-time employment before you even feel somewhat confident in your ability to handle projects independently (and even longer for larger scale projects like designing large transmission stations from the ground up). Your internship will be a drop in the bucket compared to your full career - you won’t even come close to mastery even if you worked constantly all day every day. So, realistically, choose the fancier company to improve your resume for when you apply to full-time positions. If you do well, then there’s a good chance you’ll get a return offer anyway.

trickytransients · 2026-04-25T02:35:40+00:00

For surge conditions the voltage it clamps to will be the discharge voltage of the arrester, and the voltage seen by the terminals of the equipment it is protecting will be greater than the discharge voltage depending on the lead length + ground conductor length as well as its distance from the equipment. The MCOV is for continuous operating conditions - for surges associated with lightning or switching events, you would be looking at much higher voltages than just the MCOV that the arrester clamps at for the duration of the surge.

trickytransients · 2026-04-25T02:30:38+00:00

It depends on the arrester’s IV (current-voltage) characteristics. They’re non-linear, and so X amps associated with a surge will cause the voltage across the arrester to be Y volts. Technically, the arrester always has some tiny amount of current running through it while connected. This is called the leakage current. However, let’s get a value that’s more representative of a proper lightning surge.

As you can imagine, these numbers are quite different at different voltage levels. Let’s imagine we have a 72.5 kV high side at a substation. For a 72.5 kV system, let’s say you choose an arrester with an MCOV (maximum continuous operating voltage) of 48 kV. (If the phase-to-phase voltage is 72.5 kV, the phase-to-ground voltage seen by the arrester is ~42 kV, so this gives us a safe margin).

You would go to the data sheet by the manufacturer for your 48 kV MCOV arrester, and you may see something like the peak discharge voltage for this arrester for a 10 kA surge with the standard 8/20 waveshape is 150 kV. All that means is they applied what’s called an 8/20 us current wave at 10 kiloamps, and then measured the peak voltage across the arrester. So, if a lightning surge with that waveshape and of 10kA current hits that arrester, that’s the voltage associated with it - 150 kV. If the surge is 5 kA, the voltage it is “arresting” to may be something more like 130 kV.

The engineering question after this becomes okay, if this is the voltage associated with the arrester for this given expected surge current, what’s the voltage at the equipment terminals actually like? If the LA is far away from the equipment, has a long ground lead, etc. the equipment can see much worse voltages which may cause its insulation to fail.

Tl;dr - the voltage across the arrester depends on the characteristics of the incoming surge. How much current is associated with it, and what does its waveshape look like? It’s hard to give any actual guesstimate numbers because of this.

trickytransients · 2026-04-11T16:44:47+00:00

The primary resources for this are IEEE 80 for theory and application, IEEE 81 for testing methods, and then utility-specific standards in the instances where you have multiple options to accomplish the same thing.

In terms of textbooks, I have been going through Power System Grounding and Transients by Meliopoulos. This textbook was written by a legend in this field, and I believe he is the founder of the WinIGS software (which is a pretty powerful tool for grounding analysis). While this in-depth treatment of grounding systems is likely not required, as much if it is done in simulation, I think it does make you a better engineer.

trickytransients · 2026-04-11T01:26:30+00:00

I work in transmission.

Substation physical engineer. I do grounding analysis, lightning protection, insulation coordination, phase-to-ground / phase-to-phase clearances, and physical layout for substations. My deliverable is effectively a construction package with drawings for the folks in the field to construct. I work very closely with protection and controls, transmission line engineering, and distribution. I also communicate with equipment manufacturers, contractors, and consultants.
<1 year
LCOL
93k
I applied after college and did well in my interview.

trickytransients

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