Do your math
852watts + 550watts + 400 watts = 1802.
Your power conditioner unit is able to handle only 1440 watts.
If you were powering a computer, monitor and laser printer that totalled 1802 watts, your power conditioner would NOT be able to handle the load.
Why is this comparison important? Simple. Most computer equipment items have a constant power demand.
But most audio equipment has a variable power demand. (we will ignore Class A amps)
When are you going to be actually pulling all 1802 potential watts of power?
Dynamic passages at peak volume levels.
I say give it a shot, and see what happens. I doubt you will actually ever hit the full draw of every piece of equipment at the same instant in time, and if you do, it will only pop the internal circuit breaker of the power conditioner. An internal circuit breaker that should be a resettable circuit breaker!
If you pop the circuit breaker, you will know what you will need to do... get a bigger power conditioner.
PS. There could be an issue when you power up all three pieces of equipment... many electronic items have capacitors that leak power over time and when they are powered up after an extended down time, there is a big drain of power. To avoid that huge instantenous demand, start each item a few seconds apart.