Published: 28 November 2014
Category: Q&A
Stan asks this question, which concerns a motor in star delta arrangement, and where to put the overload. It has been answered by Schneider Electric (Theme – Electrical Control):
This Q & A is one of thousands posted in our Technical Expertise area, and answered on a daily basis by our Voltimum Experts.
Question: Recently I had a motor burn out on our compressor. Upon inspection, I found that we were single-phasing the motor
This motor is wired star delta and there is no overload in line to protect it - so it carried on running until it caught fire as it couldn't trip out!
My question is, as I'm unsure of where to put the overload, where should it be - in the star or delta contactor?
I would appreciate some help via the experts.
Answer: The overload should be on the delta contactor (KM3).
Please see the attached PDF document about star delta starters, with diagrams 2.7MB file size).
To see many more Q & A in Voltimum UK's Experts Area, please click on the link. Experts from leading organisations provide online answers to your technical questions on a broad range of subjects. Our searchable database of existing Q & As now contains over 3,500 entries; you can browse through them here.