On 1/17/24 20:06, Tom Beecher wrote:
If these chillers are connected to BACnet or similar network, then I wouldn't rule out the possibility of an attack.
Don't insinuate something like this without evidence. Completely unreasonable and inappropriate.
I wasn't meaning to insinuate anything; it's as much of a reasonable possibility as any other these days. Perhaps I should have worded it differently: "if my small data centers' chillers were connected to some building management network such as BACnet and all of them went down concurrently I would be investigating my building management network for signs of intrusion in addition to checking other items, such as shared points of failure in things like chilled water pumps, electrical supply, emergency shut-off circuits, chiller/closed-loop configurations for various temperature, pressure, and flow set points, etc." Bit more wordy, but doesn't have the same implication. But I would think it unreasonable, if I were to find myself in this situation in my own operations, to rule any possibility out that can explain simultaneous shutdowns. And this week we did have a chiller go out on freeze warning, but the DC temp never made it quite up to 80F before the temperature raised back into double digits and the chiller restarted.