Contactors and Reversing Contactors. TeSys Control Relays. TeSys D, K and SK Control Relays are ranges that includes relays, mini-control relays, auxiliary contact blocks, coil suppressor modules and accessories. Contactors Contactors are relays that switch high current loads a.k.a magnetic starters. NEMA vs IEC If we compare the NEMA magnetic motor starter to the IEC magnetic motor starter, the following differences would be noticed: An IEC device is physically smaller than a comparable NEMA device. Contactor vs Relay To turn things on and off, we need devices that are switchable by the application of a current or voltage. Electrically, we have transistors and integrated circuits. I was looking up info on contactors and I came across reversing vs. non-reversing types. I did some web searches and looked at manufacturer's web sites but failed to find a definition of what reversing & non-reversing means. COuld someone please provide a concise definition? contactor or relay? Join our Community of 35,000+ Engineers. I prefer a more pragmatic definition of Relay vs. Contactor. If, when you energize the device, it goes "click", then it's a relay. Contactors and relays are electric switches. Household light switch does same job as relay or contactor, except you manually move light switch on-off. For example, you don't want to stand in front of refrigerator and switch on the compressor each time the temperature rises inside refrigerator rises. A contactor is a large relay, usually used to switch current to an electric motor or other high-power load. Large electric motors can be protected from overcurrent damage through the use of overload heaters and overload contacts. If the series-connected heaters get too hot from excessive current, the Sorry, we're unable to complete your request. We cannot complete your request due to a technical difficulty. You may return to the previous page or go to the homepage and explore other options. For immediate assistance please call us. I would go with a contactor for your application (assuming the kiln is something that fires for some time, like a pottery one). I can either feed the controller output through a small relay, to provide a switched 240v AC, or source a high-current Relay / Contactor that will accept the 12v. Relay as NO contactor. Jul 18, 2013, 04:55 pm. I am making a device that will have an external alarm in case of alarm condition or power outage. Will the relay last for years if it is essentially held open all the time? I can only find data on number of operations, which is about 100,000 times. Relay and contactor coils are usually wound using copper wire - and copper wire has a positive temperature coefficient as shown in the formulas and chart following. Throughout this Application Note, references to "relay(s)" may generally be assumed to apply to "contactor(s)" as well. Contactor vs Relay. Relays are basically switches which are primarily used for the protection of equipment. It generally uses two circuits - A control circuit and a power circuit. Contactor vs Relay. Relays are basically switches which are primarily used for the protection of equipment. It generally uses two circuits - A control circuit and a power circuit.