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Are there switches realizing these 3 states, or at least the 1st and 2nd?:

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They could be switching DC or single-phase AC. I am trying to find out if they exist, how they are called and if there are any available on the market. Looking at 230V/20A at least.

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A combination of 1 & 2 are called DPDT (double pole double throw) switches. An equivalent name you can find especially for signal switches is 2x 2:1 (multiplexer). In relay language these would be called "Dual Form C" (Form C is a changer)

The third configuration is a bit special and afaik there is no specific name for it in the classic switch nomenclature. The 2x 2:1 Multiplexers may have a global enable function, which realizes Configuration 3. For other switches, if you look for DPDT or DP3T switches (double pole triple throw), you may find switches which either have an actual 3rd position that you can leave unwired. Sometimes the "3T" is also given to switches which have 2 ON positions and 1 OFF position, where neither position is connected to the common connections. Digikey allows searching specifically for on-off-on switches.

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  • \$\begingroup\$ Thanks, it looks like there are only small ones for like 3A on the market. \$\endgroup\$ – Greendrake May 17 at 8:05
  • \$\begingroup\$ Are you looking for manual switches or relais ? Most installation switches should be able to handle 20 A. \$\endgroup\$ – tobalt May 17 at 8:12
  • \$\begingroup\$ Manual only. Perhaps I will just go with two separate simple switches and watch out to never turn them on both. \$\endgroup\$ – Greendrake May 17 at 8:13
  • \$\begingroup\$ looks like the 250VAC rated parts are usually limited to 16A which is the typical fuse rating in Europe. so if 16 A is good enough, there are options. But even when i google "20a 250v dpdt switch" i get several results. \$\endgroup\$ – tobalt May 17 at 8:17
  • \$\begingroup\$ An affordable alternative, consider a coil driven 'contactor' or 'definite purpose relay'. You will find many rated for these currents. They are common for HVAC components and the like, so they tend to be readily available & cheap. However, the cheaply built ones tend not to be terribly reliable (gotta keep those service techs working...). The type of switch and contacts are a function of the load type. Be aware of what your switching, and the requirements (resistive, inductive). This can determine the contact type. I try to avoid running large currents through panel switches. \$\endgroup\$ – Chris Knudsen May 17 at 13:54

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