Detailed instructions for use are in the User's Guide.
[. . . ] Honeywell
T8078C
INDIVIDUAL ROOM TEMPERATURE CONTROLLER
INSTALLATION GUIDE
1
Cover removal
2
Mounting T8078C
3
Wiring T8078C
1. 5mm2 (max)
4
Remote Temperature Sensor
Screen wire
14 13 12 11 10 9
Connect screen wire to terminal 9 or 10
ON 123456
System Switches
SYSTEM & PARAMETER SELECTION SWITCHES
ON
ON OFF
123456
CONTROL DEFINITION S1 S2
SYSTEM DEFINITION Heat / Cool Changeover 1-Stage Heating + 2-Stage On/Off Cooling 1-Stage Cooling + 2-Stage On/Off Heating Heat + Cool Sequence S3 S4
PROPORTIONAL BAND Xp (system dependent) 1K 2K 2K ON ON OFF ON 4K S3 ON ON S4 ON ON S5 ON OFF ON ON ON
ZERO ENERGY BAND ZEB 2K 4K S6 ON OFF
Thermo-Electric OFF ON Actuator (TPM) On / Off Modulating ON OFF ON ON
OFF OFF OFF ON
OFF OFF OFF ON ON OFF
OFF OFF OFF OFF ON OFF ON OFF OFF
1
42010558-001 R1
MODULATING CONTROL
Up to 5 x M7410C actuators (0. 7VA each) can be connected to each output. A 24V~ contactor or relay must be used to switch higher current or voltage loads.
2
ON/OFF CONTROL
Maximum rating of On/off output is 300mA. A 24V~ contactor or relay must be used to switch higher current or voltage loads.
3
TPM CONTROL (THERMO-ELECTRIC ACTUATORS)
Maximum rating of On/off output is 300mA. [. . . ] The tables and graphs opposite illustrate how to interpret the LED outputs. Fault Indication If a fault is detected, this will be indicated as a higher priority than valve position or cooling / heating demand. Faults are indicated by 1, 2, or 3 LED pulses, followed by a 6 second delay, then a repeat of the pulse sequence. Most detectable faults are associated with errors in reading sensor or setpoint values. In the unlikely event of an internal sensor or unit setpoint fault, the only option is to replace the complete controller. However, if a remote sensor fault is indicated, the most likely reason is a bad connection, so all wiring connections should be checked and re-made if necessary. Fault Internal Sensor out of range Remote Sensor out of range Faulty setpoint measurement Suggested Action Replace controller Check sensor connections Replace controller
Fault Indication
Internal Sensor Remote Sensor Unit Setpoint
0
1
2
3
4
5
6
7
8
Time 9 10 11 12 13 14 15 16 17 (secs)
Diagnostics Valve Position / Cooling or Heating Demand Valve position or cooling/heating demands are indicated by an initial code sequence of pulses, followed by the position or demand data, and this is repeated on a fixed cycle rate. The duration of the data pulse provides the important information, for example : Valve position : LED on for a duration proportional to the valve position, where 10s on = valve fully open
Modulating Control 1 2 3 4 5 6 7
On/off Control 8
TPM Control
9 10 11 12 13 14 15 16 17 18 On/off Cooling+ 2-Stage On/off Heating On/off Heating+ 2-Stage On/off Cooling TPM Cooling+ 2-Stage On/off Heating TPM Heating+ 2-Stage On/off Cooling Valve Demand 1st Stage On/off Cooling demand 2nd Stage On/off Cooling demand
Modulating Cooling+ On/off Heating
Modulating Heating+ On/off Cooling
Modulating Heat / Cool Changeover
Modulating Cool + Heat Sequence
On/off Heat / Cool Changeover
On/off Cool +Heat Sequence
TPM Heat / Cool Changeover Valve Demand (Heating Operation) Valve Demand (Cooling Operation) Valve closed
T8078C will only provide demand or position data on the current operating output, and this will be indicated by the initial pulse sequence of 1, 2, or 3 pulses. By reference to the table, the current operating mode and demand can be determined for each of the 18 possible control options.
Output Type 1 Valve position / Demand 0%
Modulating Heating
Modulating Cooling
On/off or TPM demand : LED on for an amount proportional to the on period of the cycle, where 10s on = 100% demand
Valve Demand (Heating Operation)
Valve Position (Heating Operation)
Position of Heating Valve
Heating Valve Demand
10% 50% 90% 100% 0 1 2 3 4 5 6 7 8 Time 9 10 11 12 13 14 15 16 17 (secs)
Valve Demand (Cooling Operation)
Valve Position (Cooling Operation)
1st Stage On/off Heating demand
1st Stage On/off Heating demand
1st Stage On/off Heating demand
1st Stage On/off Cooling demand
1st Stage On/off Cooling demand
Output Type 2 Valve position / Demand 0%
Position of Cooling Valve
Cooling Valve Demand
10% 50% 90% 100% 0 1 2 3 4 5 6 7 8 Time 9 10 11 12 13 14 15 16 17 (secs)
2nd Stage On/off Heating demand
2nd Stage On/off Heating demand
0%
2nd Stage On/off Heating demand
2nd Stage On/off Cooling demand
2nd Stage On/off Cooling demand
Output Type 3 Valve position / Demand
Valves closed
Valves closed
10% 50% 90% 100% 0 1 2 3 4 5 6 7 8 Time 9 10 11 12 13 14 15 16 17 (secs)
6
Valves closed
Valve closed
Valve closed
Valve closed
Valve closed
Valve closed
Valve closed
Valve closed
Valve closed
Cooling Valve Demand
Valve closed
Valve closed
Valve closed
Valve closed
Valve closed
Valve closed
Heating Valve Demand
Valve Demand
Valve Demand
Valve Demand
Valve Demand
Valve Demand
Valve Demand
Valve Demand
Valve Position
Valve Position
Valve Position
Valve Position
TPM Cool +Heat Sequence
On/off Heating
On/off Cooling
TPM Heating
TPM Cooling
ENERGY SAVINGS MODE
T8078C has an Energy Management System, where the detection of an external input signal will cause the cooling and heating setpoints to change to pre-defined setup and setback temperatures, enabling maximum energy efficiency. This input signal must be in the form of a contact closure, connected to terminals 10 and 11. In Energy Savings Mode the Setup/Setback values can be set between 2-8K by means of an on-board potentiometer. In cooling only systems (1, 7, 13) the setpoint will be increased (setup) by the set value fixed by the potentiometer. In heating only systems (2, 8, 14) the setpoint will be decreased (setback). In heat/cool changeover systems (5, 11, 17) the heating setpoint will be decreased in heating mode, and the cooling setpoint will be increased in cooling mode. In cooling + heating systems (3, 4, 6, 9, 10, 12, 15, 16, 18) the cooling setpoint will be increased by the set value and the heating setpoint will be decreased by the same amount. The effect is to widen the Zero Energy Band.
Input Wiring Connections
T8078C
14 13 12 11 10 9 8 7 6 5 4 3 2 1
Switch should be rated 30 Vdc 0. 5 mA nominal
= Normal Operation = Energy Savings Mode
ENERGY SAVINGS : EXAMPLES
(1) Modulating Cooling Energy Savings Potentiometer
4 3 2 5 6 7 8
Energy Savings Setting
4K
100%
Valve position
Energy Savings Cooling Setpoint = Normal Cooling Setpoint + Cooling Setup = Normal Cooling Setpoint + 4K
0%
Temp (°C)
Example: Setup value = 4k
Normal Setpoint
Energy Savings Setpoint
(2) Modulating Heating Energy Savings Potentiometer
4 3 2 5 6 7 8
Energy Savings Setting
4K
100%
Valve position
Energy Savings Heating Setpoint = Normal Heating Setpoint - Heating Setback = Normal Heating Setpoint - 4K
0%
Temp (°C)
Example: Setback value = 4k
Energy Savings Setpoint
Normal Setpoint
(6) Modulating Cooling +Heating Sequence 100%
Valve position
Energy Savings ZEB Normal ZEB Energy Savings ZEB
Normal Heating Normal Cooling
Energy Savings Potentiometer
4 3 2 5 6 7 8
= Normal ZEB + Heating Setback + Cooling Setup = 2K + 2K + 2K = 6K
0%
Temp (°C)
Example: Setup/setback value = 2k
Energy Savings Heating
Setpoint
Energy Savings Cooling
7
REMOTE SETPOINT ADJUSTMENT
T8078C allows its setpoint to be adjusted remotely by up to ±5K. [. . . ] If this cable is to be extended then the maximum cable run will be 20m, and the extension must also use screened cable.
T8109C1002 SENSOR T8078C 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Q979A1020 WALL-MOUNTED SENSOR T8078C
T8109C1002
Use screened cable Screen wire
14 13 12 11 10 9 8 7 6 5 4 3 2 1
14 Q979A1020 13 12 Use screened cable Screen wire
AUTOMATIC HEAT / COOL CHANGEOVER
If automatic or central Heat / Cool changeover is required, set both system switches S3 and S4 to the off position (see page 1). Automatic changeover is initiated by a thermostat positioned on the water flow pipe, detecting the presence of heated or chilled water, and sending the appropriate signal to the controller. Central changeover is initiated by a switch, and can be used to centrally switch a group of connected T8078C controllers from Heating to cooling operation. [. . . ]