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VaporTEK-3 Controller Board
VaporTEK System Description
MDE-5394B VaporTEK™/VaporTEK-3 Controller Board 110 V UL® Vapor Recovery Collection System for Encore® 500 S
Start-Up and Service Manual · March 2019
Open-loop vs. Closed-loop Flow Control
For Collection Only systems, the A/L Ratio is controlled with prior knowledge of pump
operation, that is, the calibration curve. This is an open-loop control scheme.
In Coll Monitoring systems, the primary control of the A/L Ratio is the same as in the
Collection Only systems, using the calibration curve to set the appropriate pump speed.
However, making continuous measurements of the vapor flow allows us to control it more
precisely than when the flow is not measured. In addition to using the calibration curve, which
drives the pump close to the fuel flow, there is also a closed-loop control function that refines
the speed command to deliver an A/L Ratio closer to 100%. This function is performed by a
Vapor Monitoring system, which is not a part of this document. For more information about
close loop systems using a vapor monitoring system, contact your dispenser supplier.
Changes in System Performance
The calibration procedure maintains a close relationship between the fuel flow and vapor flow
as long as the system performance remains constant. However, the system performance varies
over the lifetime of the system. Over time, the seals on the pump piston wear, the system
develops slight leaks and restrictions, and other long-term effects cause the flow to change at
every speed. The flow can either rise or fall, but it typically falls as the system ages. Thus, the
vapor flow will begin to deviate from the fuel flow, and the A/L Ratio will go out of range,
initially only on occasion, but eventually often enough that it will repeatedly fall below the
allowable. For information about calibrating the system, refer to
. Whenever the calibration procedure is performed, the computer develops a new
curve to use for driving the pump in the future. The system can be recalibrated at any time as
required to return the A/L Ratio closer to its target value until the maximum allowable speed
of the pump is reached (1200 rpm) for each side, and no more flow is available. At this point,
the pump needs to be replaced.
VaporTEK-3 Controller Board
VaporTEK-3 Controller Board is shown in
. This is the motor driver
that translates a fuel flow into speed information delivered by the RS-422 serial or
VVAC-Port Encore 500 S interface connection and drives the motor on this calculated specific
speed.
Mode selections for the VaporTEK-3 Controller Board require jumper settings as shown in the
following table:
Configuration Type
VaporTEK Controller Mode
Mode Selection
J1
J2
J3 - PROG.
VaporTEK Plus
Electronic Signal of Fuel Flow Required
No
No
No
Board Programming Mode
Power OFF/ON Cycle required
No
No
Yes
