Bulk milk tank control

On bulk milk tanks with evaporator plates in the belly of the tank, where is the temperature sensor and where are the thermostats for the compressors?

Also, how are multiple compressors for a bulk tank typically operated? With a tank that has two compressors, for example, with two separate evaporator plates, is it typical for both compressors to have the same setpoint? Or would they be staged, so one came on at say 38oF and another at 40oF if the load was too much for just the first to maintain 38.

Thanks in advance for your help.

i pressume you are taling about a dx tank the sensor is useually in the front of tank via a access port it is controlled by a stat or digital controller that opens mag valves thus switching lp switch to feed contactor and comp the various comps are switched on useually on a staged time delay timer so each comp fires up seperatley also on some if not a lot of milk in it you can isolate how many units you want on

Big tanks [over 10000L use SS electrodes in different heights inside the tank and milk touches them' a circuit closes and it operates one or two Sv, depend on the set up.

Timers are bad idea when there are more then 2 units, it can start a unit while the evaporator plates are above the milk and get liquid flushing the compressor.

Newer tanks typically vary the number of units running depending on load and may be on hyperform units witch don't have mag valves for pump down. Older dx units will usually have two seperate circuits with one evap on the bottom of the tank and one on the sides. You can usually opt to only use the bottom evap if you have a low milk yeald. The stat probe is usually behind a rubber bung on the bottom of the tank at the front.
Roger.

Tank needs and agitator that keeps milk moving around constantly. The Tstat in a well that is half way down vat and half way between centre point and outer diameter.

Thanks, everybody, for your replies.