I have a 10 bay (10 bay is set up to weep) and an 8 bay that I run a similar system as 2Biz. I will be converting the 10 bay to the same system in the spring. I just took that one over and do not have enough time to build the system before it gets cold.
On the 8 Bay I have 2 FB delivery systems, 1 regular soap 1 Winter Blend, Regular soap has a master NC Solenoid and Winter Blend has a NO solenoid. Each soap and air is fed to the manifold in the heated trough.
All the following is controlled by a PLC.
Step 1 Temp hits 33.6 and must hold there or below for 5 minutes. If temp hits 33.6 and holds for 4 minutes then goes back to 34 then back to 33.6 the timer resets (the temp controller im using will actually read to the .1 degree).
Step 2 After hold time has passed at 33.6 Master Solenoids for Foam Brushes are deenergized to reach their normal state
Step 3 Foam brushes are purged with air only for approx 20 seconds per bay 2 bays at a time. This blows the main amount of regular soap from the bay hose.
Step 4 Each Bay turns on the Foam Brush (air and Winter Blend now) 2 bays at a time as if a customer were using it for approx 20 seconds per bay. This helps clean any remaining regular soap product from the bay hose.
Step 4 Each Bay repeats Step 3 blowing out each bay hose twice. It cycles through all bays 2 at a time once then all bays 2 at time a second time
System has now been converted from regular soap to Winter Blend and is sitting in a neutral state with winter blend soaps active. The system will switch back automatically to regular soap when the temperature rises back above 35 and holds that temperature for 10 minutes.
If a customer activates a foam brush for more than 5 seconds it will repeat the blow down (Step 4) 10 minutes after the bay timer has turned off
I also have manual ball valves in the main line to bypass the solenoids if i feel i need to manually override the system for 1 soap or the other, or during the summer i can turn all outputs off on the HMI Screen to a neutral state and feed regular soap bypassing the NC solenoid.
I have it set to not do all the bays at once due to allowing the main compressor to keep up as usually during the cycle for the Foam brushes the Blow down functions on my
razor will probably activate at the same time. You have to allow the compressor sufficient recovery time or you will run out of air.
Its a very simple system after you learn how to use it.