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Comment by jacquesm | Hacker News Reader

That's a great way to lose the breaker though. If you're lucky the latch will fail. If you're unlucky it will weld shut.

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Not ideal, but it was the only thing that worked. This was attached to a million dollar piece of equipment, so any remedial electrical replacement work would have been slightly inconsequential. Thankfully, it was one of those machines that you turned off as infrequently as possible, so we did not have to do this procedure too many times.

The vendor did get the hint, and the second iteration of the device did slowly warm up the pumps so this process would no longer be required.

Yes, soft start is the way to go. Also: proper industrial breakers allow for temporary overload. I have a couple of pieces of gear that have inrush currents well over the limit of a normal breaker so I put them on a slow one and now it is fine.

https://onccy.com/how-to-choose-between-type-a-b-c-and-d-min...

> Also: proper industrial breakers allow for temporary overload

Notoriously a crescent wrench makes an excellent 1000A slow blow fuse

A 5/32" flat-blade screwdriver makes an excellent fast-blow fuse when dropped across exposed bus bars. And you can re-use the remains of the handle to stir your coffee once you've retrieved it from across the room.

Styropyro shows something like that!

https://youtu.be/OC7sNfNuTNU

Soft-start is in theory the way to go, but it's very dependent on the motor type, there's a whole pile of different methods required for induction motors depending on whether they're capacitor-start, permanent split capacitor, shaded-pole, etc, so you can do it in some cases by lowering the voltage, or with a VFD, or a VSD, or the old-fashioned way with a centrifugal switch but that requires very careful handling. If as the OP said it's running million-dollar equipment you probably don't want to monkey with it at that level.

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