Manual
3. SCR Drive Setup
PNEG-1544 Vision SCR Board Calibration 9
SCR Board Terminal Locations
Terminals L1 and L2 are the input terminals. When the unload system is turned ON, there should be 
220 VAC across these terminals. (See Figure 3C.)
Terminals A+ and A- are the output terminals. The voltage across these terminals is DC and will vary 
depending on the setting on the speed control dial.
NOTE: For this calibration procedure, disregard the minimum and maximum potentiometers on the 
SCR Board.
IMPORTANT: If installing a new SCR Board, be sure to remove the resistor (shown in Figure 3C below) 
from the old board and install it in the new board. To do this, pull the resistor out from the 
2 pin socket of the old board and install in the same socket on the new board. Pictured 
below are horsepower resistors. The original components that came with the dryer 
should remain.
Figure 3C SCR Board Terminals
Resistor
P3 P2 P1 L1 L2 A+ A-










