WattMaster WM-WCC3-TGD-01B - Manual (Page 521)

12. WCC III INSTALLATION
GUIDE
WCC III Technical Guide 12-25
The DC voltage range along with the ramp speed is set at the PI
board. The ramp speed can be adjusted from 23 seconds to 38
minutes, and the maximum range is 0-14.5 volts DC.
To control a VFD drive from a SAT III controller using the
Proportional-Integral board, you must use two control outputs and
a circuit board (PI Board) that we no longer make. WattMaster
Controls does not make the PI Output Board anymore, but Kele
makes a similar circuit board that should work. It is a Tri-State-to-
Analog Output circuit board (Kele Part # PWA-2T).
If only one contact closure is available to drive the PI Board, move
jumper J01 on the WattMaster PI board to the B-C position and use
the SAT III’s control output in the Dual Limit mode to control the
PI Board. Although when using this method with the WattMaster PI
Board, the DC voltages supplied by the WattMaster PI Board will
either be increasing or decreasing at the set ramp speed depending
on if the contact is open or closed.
The Global Analog Mode 9 Dual Ramp Screen was created to help
emulate the old WattMaster PI board in software. It basically uses
the control set points of two control outputs on a satellite controller
to control a single analog output on a satellite controller and should
be used when controlling an analog actuator or VFD that needs to
have an analog control setpoint. See Section 3 for further details on
Satellite programming instructions.
The Proportional-Integral (PI) Board -
connection points
All of external connections to Proportional-Integral (PI) Board
connection points are non de-pluggable screw-cage type of wire
clamped based terminal blocks.
24 VAC (TB1-5) & GND (TB1-6)
The PI board requires a 24 VAC power supply which is connected
to these terminals. The PI board is generally powered by the same
24 VAC transformer that powers the satellite controller. The GND
connection points must be the same between the PI board and the
SAT III Controller.
HEAT (TB1-1) & COM1 (TB1-2)
When 24 volts AC is supplied between the “HEAT” and “COM1”
terminals, the DC voltage supplied by the PI board will start
increasing at the set ramp speed.
COOL (TB1-1) & COM2 (TB1-4)
When 24 volts AC is supplied between the “COOL” and “COM2”
terminals, the voltage supplied by the PI board will start decreasing
at the set ramp speed.
ANALOG OUT (TB2-1) & GND (TB2-3&4)
The “ANALOG OUT” and “GND” terminals supply the DC
voltage from the PI board.
Adjust Minimum Voltage
The PI board is factory set for a minimum voltage of 0 VDC +/-
0.2 VDC. If you want a minimum voltage other than 0 VDC, you
can reset it by adjusting the potentiometer (pot) labeled “R9.” The
voltage between test point #3 (labeled “TP #3” on the PI board)
and ground is set 300 mV lower than the desired minimum voltage.
That is to say, if you want 5 VDC as the minimum voltage to be
supplied between the “ANALOG OUT” and “GND” terminals,
adjust pot “R9” to get 4.7 VDC between “TP #3” and “GND.”
NOTE: The minimum voltage setpoint must be lower than the
maximum voltage setpoint.
Adjust Maximum Voltage
The PI board is factory set for a maximum voltage of 14.5 VDC
+/- 0.2 VDC. If you want a maximum voltage other than 14.5
VDC, you can reset it by adjusting the potentiometer (pot) labeled
“R10.” The voltage between test point #2 (labeled “TP #2” on the
PI board) and ground is set at 300 mV above the desired maximum
voltage. That is to say, if you want a maximum voltage of 10 VDC
to be supplied by the “ANALOG OUT” and “GND” terminals,
adjust pot “R10” to get 10.3 VDC between “TP #2” and “GND.”
NOTE: The maximum voltage setpoint must be higher than
the minimum voltage setpoint.
Adjust “Ramp” Speed
The ramp speed is the time it takes for the DC voltage between
the “ANALOG OUT” and “GND” terminals to change from the
minimum voltage to the maximum voltage and vice versa. The ramp
speed is factory set at about 19 minutes. If you want a ramp speed
other than 19 minutes, you can reset it by adjusting the potentiometer
(pot) located at R2. When R2 is fully counterclockwise, the ramp
speed is 38 minutes (+/- 10%). When R2 is fully clockwise, the
ramp speed is 23 seconds (+/- 10%). As the voltage is ramping up,
the small light labeled D1 will fl ash and as the voltage is ramping
down, the small light labeled D2 will fl ash.
PI Board Connection Points