T7079A,B SOLID STATE REMOTE TEMPERATURE CONTROLLERS
5
63-2572—04
Fig. 7. Typical line-voltage (120 Vac) wiring application.
OPERATION
Control Algorithm
On/Off Control
When used in heating mode, the relay is:
— Energized at setpoint minus differential on temperature fall.
— De-energized at setpoint on temperature rise.
When used in cooling mode, the relay is:
— Energized at setpoint plus differential on temperature rise.
— De-energized at setpoint on temperature fall.
NOTE: Each stage LED lights when its stage is energized.
The power LED lights when the controller is
connected to 120/230 or 24 Vac.
Differential (Stage and Interstage)
Adjustment
The stage and interstage differential values are adjusted using
the internal potentiometers (see Fig. 8). Values for setting are
marked on the inside cover:
— Minimum stage differential (DIFF1 or DIFF2): 1°F.
— Interstage differential: 0°F to 35°F.
NOTES:
—
Actual minimum differential is typically between
1°F and 4°F. It is influenced by device tolerances
and the rate of temperature change.
—
The setpoint knob setting is the stage 1 setpoint.
—
The stage 2 setpoint is created using the stage 1
setpoint and the interstage differential:
— When stage 2 is used for heating, the stage 2
setpoint is the stage 1 setpoint minus the inter-
stage differential.
— When stage 2 is used for cooling, the stage 2
setpoint is the stage 1 setpoint plus the inter-
stage differential.
Fig. 8. Adjustments (potentiometers and switches).
TWO-STAGE HEAT
1.
Set ST1 and ST2 switches to HEAT.
2.
Set interstage (INTER) and differential (DIFF1, DIFF2) to
desired settings.
3.
Position the setpoint knob at the setting for stage 1.
TWO-STAGE COOL
1.
Set ST1 and ST2 switches to COOL.
2.
Set interstage (INTER) and differential (DIFF1, DIFF2) to
desired settings.
3.
Position the setpoint knob at the setting for stage 1.
ONE-STAGE HEAT/ONE-STAGE COOL
1.
Set ST1 switch to HEAT and ST2 switch to COOL.
2.
Set interstage (INTER) and differential (DIFF1, DIFF2) to
desired settings.
3.
Position the setpoint knob at the setting for stage 1.
NOTE: See Fig. 9 for an example setup.
Fig. 9. Example one-stage heat/one-stage cool setup.
NOTE: Keep in mind that, based on the terminal board
labels, the stage 1 relay is J4; the stage 2 relay is J5.
J5
J4
SENSOR
J1
M17563
STAGE 2
LED
STAGE 1
LED
L1
(HOT)
L2
NC
NO
NO
COM
NC COM
COM
120V
240V
DIFF2
ST2
ST1
DIFF1
INTER
COOL
HEAT
M17573
0
10
35
25
1
10
30
20
1
10
30
20
ST1: HEAT
ST2: COOL
DIFF1: 2°F
DIFF 2: 4°F
INTER: 6°F
80°F
76°F
70°F
68°F
SETPOINT
SETPOINT
KNOB SETTING:
M21062
STAGE 2
DIFFERENTIAL 2
DIFFERENTIAL 1
INTERSTAGE
STAGE 1
COOL ON
COOL OFF
HEAT OFF
HEAT ON
