A motor controller, above 1 hp, and usually used on a 3 ph line, is a glorified relay. It however has, added features of thermal cutouts on each of the phases on the load side of the relay. It's normal electrical name is a contactor. The actuating coil is usually 120 VAC, however it can be in special cases 24 VAC or 24 VDC. Some of the reasons it is used is: 1. To start all 3 phases at the same time to the motor. 2. Provide (in some cases) a local START / STOP pushbutton station. 3. Provide trip protection in case of overload or stall of the motor. 4. Allow remote START / STOP capabilities / facilities. They are usually big and bulky because the contacts are rated to handle the high horsepower inductive current ratings. They also must make and break the circuit quickly to quench the arc over so as not to weld the contacts together. More questions about this topic are welcome. Bill Inderrieden In a message dated 7/28/2017 12:16:23 P.M. Eastern Daylight Time, vcf-midatlantic-request@lists.vintagecomputerfederation.org writes: Message: 6 Date: Thu, 27 Jul 2017 19:14:27 -0400 From: Evan Koblentz <evan@vcfed.org> To: Vcf <vcf-midatlantic@lists.vintagecomputerfederation.org> Subject: Re: [vcf-midatlantic] Museum power / Running bigger machines Message-ID: <11095b74-0b91-4f41-9828-84e6b181650c@vcfed.org> Content-Type: text/plain; charset=UTF-8
Maybe Martin will provide one to us but I didn?t ask. I found one on Amazon for $142.00 https://www.amazon.com/Starter-definite-magnetic-Square-8911dpsg23v09/dp/B00 GGPZ9P4
Well you just posted on the public list which he reads, too. :) Anyway: what's a magnetic motor controller?