r/Wastewater

Finally passed my
G3 exam

Feels so good

Had this in my head after the thread last week. Overload keeps tripping on a lift station pump, so the pump gets pulled. Then rebuilt. Then replaced. A week later it trips again, and the problem was a pitted contactor in the panel the whole time.

One pole ends up dropping a few volts when it should be close to zero. That phase runs low, and a small voltage unbalance turns into a much bigger current unbalance. The motor gets hot, overload trips, and the pump takes the blame.

Do you guys check voltage drop across the poles before you pull a pump, or is it mostly swap it and see?

We've received a few suggestions about allowing media in comments. So, new this week: r/Wastewater allows pics in comments, with a few guidelines.

- please keep it on topic. A) Answering a question by commenting a picture of how something works at your plant: perfect. B) A tongue-in-cheek image that's somewhat on topic with the post, sure. C) Random jokes, a picture promoting your project... those are spam and subject to our sub's Rule 3. D) r/Wastewater Mod Team and platform admins reserve right to discretion on the above.

- GIFs and videos are currently not allowed, to avoid clogging the feed.

Hey I’m currently looking to study for the class 1 exam for wastewater treatment in Ontario. Wondering if anyone had any recommendations on what guides to use and/or quizzes. Thanks!

Most of the time, I see the Pounds Equation solved without SG:

lbs = Volume * Concentration * 8.34

However, I was taught the equation with SG in it:

lbs = Volume * Concentration * 8.34 * SG

Does someone have a clear explanation of when to include SG in the equation versus not? I can't seem to find explicit discussion about this online. Even engineers at my company are not sure what the answer is.

Thank you!