The Model UASPT is an evolved product specifically designed to lead/lag two compressors where one compressor has controls that are not accessible to the standard AutoSync technology.  Pressure control is supplied by the UASPT via our included very accurate pressure transducer with display.  The UASPT is attached to the accessible compressor.  

The UASPT controller can also be installed in the conventional way to operate each compressor in automatic lead/lag control when both machines are accessible to the controller.

Enclosure size is 11” x 7” x 6”, NEMA 12.


1.    Wire the UASPT to the compressor starter coil (115v) removing the existing connection   from the mechanical pressure switch.

2. Connect the common system pressure control line to the UASPT.

3. Power the controller – 1/60/115v.

4. Set the required “bracket pressures” on the Pressure Transducer.

5. Power the compressor with the “on-off” power switch.


Pressure Transducer up to 250 psi  (standard unit is for pressures up to 150 psi)


How the Lead/Lag Function Works on the UASPT

The lead/lag function is accomplished by the  automatic switching of the controller pressures 

bracketing the non-accessible compressor permanent pressure setting.  The UASPT controller 

is simple to install and brilliant and foolproof in function.

The non-accessible compressor is typically a rotary screw machine that has the Pressure Transducer and 

all controls enclosed in a circuit board. This precludes any lead/lag attachments from an outside source.

The accessible compressor is typically a machine that is controlled by a mechanical pressure switch.

The hour meter records the “on” time for the accessible compressor.

Compressor loaded light indicates when the compressor is pumping.

The operator can by-pass the auto lead/lag function by selecting the Compressor 1 lead or Compressor 2 lead position on the panel.

Example of the “pressure bracket” design of the UASPT-115:  

Comp 2 

Lead    -   Accessible Compressor:

                       Set Lead Pressure:  Off - 130 psi      On - 120 psi

Comp 1 - Non-Accessible Compressor:

                       Permanent set:  Off - 125 psi     On 115 psi

Comp 2

Lag       -   Accessible Compressor:

                       Set Lag Pressure:    Off - 120 psi       On - 110 psi

UASPT installation instructions

Files coming soon.

Maximum efficiency with universal autodual controllers!