Need some pointers to get started with this panel - Page 1
Forum section: electronics / general

author: Anjum9694
author_rank: Newbie
timestamp: November 08, 2023, 12:42:59 pm
content: Greetings all,I'm not sure if this is the right place to post butI'm having some problem with my electric motor getting overloaded. So far I haven't seen the magic smoke escape from anything. Perhaps maybe one of the windings is shorting? But I'd like some pointers in this panel images if my electric motor keeps tripping from overload current. Will post thermal images shortly.

author: bookaboo
author_rank: Frequent Contributor
timestamp: November 08, 2023, 01:16:06 pm
content: Hate to be blunt but 3-Phase electrics isn't for beginners. You need to consult a local professional.

author: Gregg
author_rank: Super Contributor
timestamp: November 08, 2023, 09:00:32 pm
content: More information would be helpfulWhat size is the motor? A picture of the motor nameplate might be helpful.What else is controlled from the cabinet pictured; there are two sets of contactors and the one on the left appears to be a reversing contactor which seems odd for a pump.When does the overload occur; on startup, after it gets hot, etc.Do you have a meter that is rated for the power available?Have you checked the connections at the motor? Pumps tend to be in harsh environments and the connections to the mains are not always properly made to withstand long term moisture etc.The first step is to measure the current on each wire going to the motor when it is running. The current should be very close on all 3 phases; if not you most likely have either a bad connection or a bad winding.

author: Anjum9694
author_rank: Newbie
timestamp: November 09, 2023, 02:25:52 pm
content: Will post NP soon havent taken a pic yetThe cabinet only controls the electric pump. I noticed that the overload happens after a short while after the pump is started, presumably the overload happens after the pump transitions from star to delta connection(?)There is a display on the cabinet door that shows the phase currents, I am attaching a video. It turns off itself after a whilehttps://youtu.be/tKk0tHGnTlY.

author: Anjum9694
author_rank: Newbie
timestamp: November 09, 2023, 02:28:31 pm
content: Quote from: bookaboo on November 08, 2023, 01:16:06 pmWe all gotta start somewhere.. Appreciate all the help I'm getting.

author: Gregg
author_rank: Super Contributor
timestamp: November 09, 2023, 06:53:41 pm
content: Star start delta run sheds new light on the situation.What is actually tripping? What component needs to be reset after it trips?What is the amperage of the motor? What type of pump and what are you pumping?From the information provided, I’ll try to explain how this works; I may be somewhat misguided by lack of information.I’m not sure what the gray panel is for.In the red panel, below the lower circuit breaker are three current transformers. These CTs are used by the control board to measure motor current and determine when to transition from star to delta during startup and probably monitors running current to shut it off if overloaded. I don’t see other motor overload protection.The transition from star to delta usually involves high current for a short duration. The motor is spinning from the star start and generating power out of phase with the delta configuration. Machines I’m familiar with use resistor banks to limit the current during transition; I’m not sure if your system has any means of mitigating this spike. I would inspect the contacts for the motor contactors, with the power off, of course.Other problems may occur with high ambient temperature and/or humidity at the control panel.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 13, 2023, 01:53:26 am
content: Quote from: Anjum9694 on November 09, 2023, 02:28:31 pmyes, I completely agree with that, but high voltage and amps 3-phase circuits it not a good way to get started with anything electric. Apart from risk of of personal accidents, there is also a real chance you make it worse and repairs can get very expensive quickly.