Installation
ACC-SVN136E-EN
9
Controller Settings
Jumper Position for TTA Models (Cooling
Only)
For non-heat pump applications, the heat pump select
jumper must be in the Default (N.O.) position, and the HP
terminals must be left unconnected. See
Jumper Position for TWA Models (Heat Pump)
For heat pump applications, the heat pump select jumper
must be in the (N.C.) position, see
.The heat
pump terminals accept the 24 VAC signal from the switch
over valve holding coil.
Important:
Do not apply a voltage higher than 30VAC to
the HP terminals.
Operation
Upon startup, the motor will hard start for the length of
time dictated by the dial setting. After the hard start time
has elapsed, the motor speed will be controlled by the
transducer reading pressure. When the motor is running
at full speed, the green light will turn on.
As the sensed pressure decreases, the output voltage will
decrease, the green light will turn off and the yellow light
will turn on during this motor variable speed. Note that the
output voltage may decrease to the determined cutout
speed, which is dictated by the cutout speed dial. Upon
reaching the cutout speed setting, the output voltage will
go to zero volts and the yellow light will turn off and the
green light will remain off.
Setting the Pressure Setpoint
When using pressure transducers, the control will
maintain condenser pressure between 20psig above and
20psig below dialed pressure setpoint. The dial pressure
setpoint range is 35psig to 465psig.The pressure setpoint
should be adjusted to 250psig initially. Monitor the
condenser discharge pressure and adjust the pressure
setpoint so the condenser fan operates at full speed when
the ambient temperature is greater than 75°F and
modulates speed when the ambient temperature is below
70°F.
Note:
There is no exact correlation between dial
temperature and pressure scales on the control.
Setting the Cutout Speed
The cutout speed dial adjusts the motor voltage range.
Ball Bearing Motors
Note:
Only ball bearing motors are supplied with kit.
Set the cutout speed dial to the MIN position in the ball
bearing range. This position offers the greatest range of
speed control. At the MIN setting the motor can run down
to approximately 20- 30% of the full line voltage.
Setting the Hard Start Speed
During the hard start mode, the motor runs at 50% of full
capacity for the time dictated by the hard start setpoint.
The position of the hard start dial determines the time
period of the hard start mode.
Figure 9.
Jumper position for TTA
Figure 10.
Jumper position for TWA
N.O.
N.C.
Figure 11.
Pressure setpoint
Figure 12.
Cutout speed
