Quote from: HoleShot on February 27, 2018, 12:14:36 AM

Almost all electronics have an MOV in their circuit. I took apart a Bitmain PSU and looked but I didn't find one. There are two thermisters for start up surge protection but I didn't find MOVs.

We stopped putting those MOVs inside appliances long ago for some very obvious reasons.

A surge that is a voltage between to wires is rare and is made irrelevant by what a power supply does. If the surge is so large as to harm a power supply, that MOV vaporized long ago. In short, the MOV is only a potential fire. And does nothing (is woefully too tiny) to increase protection.

A transient that does damage is best described by numbers. Let's say that MOV has a 330 volt let-through voltage. A 5000 volt surge is incoming on the AC hot (black) wire. Now it is 5000 volts incoming to the supply on one wire and 4670 volts on the neutral wire. Where is protection?

Best protection for a miner is best as distant as possible to a miner (and everything else since all other appliances also need that protection). And is as close as practicable to single point earth ground. Protection increases with every foot shorter to earth. Protection increases with increased separation between miner and protector. A concept called impedance applies.

Best protection is a 'whole house' solution provided by companies known for integrity. Including Intermatic, Square D, Ditek, Siemens, Polyphaser (an industry benchmark), Syscom, Leviton, ABB, Delta, Erico, General Electric, and Cutler-Hammer (Eaton).

Which less robust appliance most needs this protection? Plug-in protectors. Since these near zero joule devices (from companies not known for integrity) can also make electronic damage easier. And sometimes even create fires.

As another has also demonstrated, this superior solution is also a least expensive solution - about $1 per protected appliance. Because and again, if a miner needs protection, then so does a dishwasher, clocks, furnace, GFCIs, all recharging electronics, clock radios, dimmer switches, refrigerator, central air, garage door opener, and every smoke detector.