Saving power at the Sensor Racks?

The Physical Plant Manager at our facility thinks that, during "dark" days, we should shut down our 7) 96 racks to save energy by throwing the two main breakers.  I've already told him that the rack fans shut off automatically and the CEMs don't use any power when inactive.  I am correct, yes?

With all circuits off, and the fan stopped the absolute maximum quiescent power drawn by a ESR96 Sensor+ rack at 230VAC is roughly 70W.

Most of that power is due to the max 100-200mA leakage current through an 'off' triac - so it's a lot less at 120VAC, and it's even less if you've not got loads connected to every dimmer circuit.

In general, power savings from properly powering off compared to 'standby' are generally minimal, and may actually be wiped out by the 'startup' requirements. I remember doing some work at a big plant to find out the energy saving from shutting down their air compressor plant - it turned out that they actually used more energy 'pumping up' the system than they'd burn by leaving it running for a day. (Two days gave a saving though).

The startup energy requirement of a Sensor+ rack is pretty tiny though - the only additional current during boot compared to quiescent is that it runs the fan for a bit.

So yes, you'll save a little bit - but not much.

It may be worthwhile shutting off when you're dark for a few days, but remember that the isolators themselves have a limited lifespan!