Super Systems 9120 with TS - Manual (Page 14)

SSi 9120 Touchscreen Interface
4586 – 9120 With Touch Screen Interface Page 14 of 80
The following is an explanation of the dual/single and direct/reverse properties:
Dual – This has two output relays which can increase and decrease to achieve your SP.
Single – This has one relay which works in only one direction to achieve your SP.
Direct - If the PV - SP is a positive number and the output would bring the PV down toward
setpoint, then that is direct.
Reverse – If the PV - SP is a negative number and the output would bring the PV up toward
setpoint, then that is reverse
Example: If a 12 mA output drives a 0 degree F temp. (PV) up to a 1200 degree F temp. (SP),
this would be REVERSE, and since this would take a SINGLE output from the controller, the Mode
for the Temperature Loop is Single Reverse.
The mode values can be:
Dual Reverse
Single Reverse
Dual Direct
Single Direct
Integral Preset
This field provides an offset for the starting point for PID control, also referred to as “Load Line”
or “Manual Reset”. Clicking on the value will allow the user to change the value. The range for
the integral preset is -100 to 100.
Cycle Time
Clicking on the value will allow the user to change the value. This field is typically set to the valve
travel time multiplied by 1.5. The cycle time range can be 0 – 500.
Setpoint Change Limit
This is a smart time feature that allows the Process Loop to use PB only without Reset until the
Process Variable drops below the percent output set under this category.
It is used to eliminate overshoot.
The Output percentage selected under this category
must be above the normal operating output
percentage of the furnace at heat.
Clicking on the value will allow the user to change the value.
Example – if the furnace runs at 40% output at heat for the maximum load, the setpoint change
limit should be set to 60%
.
The value can be:
OFF
80 %
70 %
60 %
50 %
40 %
30 %
20 %
Low Limit
This is the low limit field. Clicking on the value will allow the user to change the value. The range
is –100 to 100.