Vacuum Motor Control Circuit Overview (Auto Mode) - Clarke Clean Track® L24 56317170 Service Manual

The wastewater and air enter the vacuum system through the extraction/vacuum shoe assemblies. The air and
wastewater move through the vacuum hoses at high speed until they reach the recovery tank.
Once the air and wastewater reach the recovery tank, the air slows down because of the increased volume (large
size) of tank. With the decreased airspeed, the heavier water falls to the bottom of the recovery tank. The airflow then
continues through the tank, vacuum fan inlet screens and vacuum motors, then is exhausted out of vacuum exhaust
acoustic foam. No wastewater ever actually moves through the vacuum motors, just the working air.
The vacuum system uses a float switch to prevent the tank from being overfilled and stops any water from being sucked
into the vacuum motors.

Vacuum Motor Control Circuit Overview (Auto Mode)

See Figure 10.
Contactors K2 and K3 supply positive voltage to Vacuum Motors M6 and M7 respectively. M6 and M7 get their negative
ground from negative battery terminal SP2. Float Switch S2 must be open to prevent the Recover Tank Full Sense
terminal (J3-5) on A1 from connecting to ground.
+ (Positive) Circuit input starts with:
• A closed S1 Key Switch that supplies the needed positive voltage to the K2 vacuum motor contactor (BLU/RED wire),
the K3 auxiliary vacuum motor contactor, pin #5 - KSI (BRN wire) on the A2 Speed Controller and pin #J2-8 (BRN
wire) on the A1 Control Board. Note that the A1 control board scrub-on button must also be depressed (enabled).
This operator command lowers the brush deck.
• Once the K2 and K3 loads are closed, the needed positive voltage is supplied to motors M6 (BLU wire) and M7
(WHT/VIO wire) from the battery post.
- (Negative) circuit input starts with:
• Battery negative ground inputs at the A1 control board and at the A2 speed controller terminal B-.
• A negative voltage output from the A2 speed controller pin #6 - Brake (-) to the A1 control board pin J1-8 For./Rev.
(RED/BLK wire) Note that the A2 speed control brake negative output (pin #6) occurs whenever the R1 direction
throttle pot is moved off its neutral setting. This operator command happens when the drive paddle is pushed or
pulled to run the wheel drive motor in forward or reverse with the vacuum enabled.
• The recovery tank float switch (S2) must be open to prevent negative input to the Recover Tank Full Sense terminal
(J3-5) on A1. This allows negative voltage output from the A1 board terminals J2-1 (BLU/RED wire) and J1-10 (ORN/
RED wire) to complete the K2 and K3 solenoid coil circuits (positive and negative) and pull in the solenoid load
contacts making the vacuum motors run.
Note: Refer to Figure 11 for an illustration of the float switch configuration.
38 - Form No. 56043161 - Clean Track L24
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