About Us

FROM HUMBLE BEGINNINGS TO INDUSTRY LEADER

100% Employee Owned. Industry Leading. Minnesota Based.

Steve Johnston founded SJE (S.J. Electro Systems, Inc.) on July 2, 1975. Over the past four decades we have earned a reputation for excellence by delivering the most reliable integration of engineering and manufacturing capabilities in the industry.

We are comprised of a group of well-respected brands — CSI Controls, Primex, SJE Rhombus — all known for their innovation and quality. With locations throughout the United States and Asia, clients around the world depend on our family of companies to design and manufacture their most critical projects.

From early pioneering efforts like the Tank Alert® alarm and Sensor Float® control switch, to today’s wide range of technologically advanced, energy efficient, and cost-effective solutions, we have grown into the leading water controls technology company.

We’re committed to creating innovative solutions that help municipalities, industrial customers, and homeowners meet their liquid level control needs. We also offer custom PCB solutions through our SJE Rhombus brand, including circuit board design, embedded controls and software, and more.

Our new product designs endure extensive in-house and field-testing before submittal to recognized independent laboratories for safety testing and approval. This ongoing commitment to quality ensures that our customers get dependable, trouble-free products.

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SJE is an industry leader, with 60+ patents, an R&D team with 100+ years of industry experience, and 62 engineers. We produce 70,000 control panels per year, from $200 panels to multi-million dollar projects.

A Commitment to Quality

New product designs endure extensive in-house and field testing before submittal to recognized independent laboratories for safety testing and approval. Each product is constructed of materials of the highest quality with expert workmanship and delivered in responsive lead times. This commitment to quality ensures you a dependable, trouble-free product. SJE is so confident in the superior quality and performance of our controls, that nearly every catalog product leaving the factory is backed by a five-year limited warranty.

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