Honeywell T7770A-G Wall Modules
SPECIFICATION DATA
GENERAL
The T7770A through G are a family of direct wired wall modules designed for use with Honeywell Excel 600, 500, 100, 80, 20 (all fully programmable) and W7750, W7751, W7752, W7753, W7761 Controllers. All models feature a space temperature sensor. Some models include setpoint adjustment, override with LED, and a fan switch.
SPECIFICATIONS
Models: See Table 1.
Construction: Two-piece construction consisting of a cover and an internally wired subbase. Field wiring, 14 to 22 AWG (2.0 to 0.34 sq. mm), connects to a terminal block in the subbase. The wall module is activated by plugging into the prewired subbase.
Mounting Options: The T7770 can be mounted on a standard two by four inch junction box or on a 60 mm diameter junction box. The subbase also provides the slotted hole pattern for the T7412 Wall Module series individual room control devices.
Dimensions (H/W/D): 5-1/16 x 3-1/8 x 1 in. (128 x 80 x 25 mm).
Environmental Ratings:
- Operating Temperature: 45 to 99°F (7 to 37°C)
- Shipping Temperature: -40 to 150°F (-40 to 65°C)
- Relative Humidity: 5% to 95% noncondensing
- Temperature Sensor Operating Range: 45 to 99°F (10 to 37°C)
FEATURES
- Models with setpoint adjustment.
- Models with occupied/unoccupied override (bypass) with LED.
- Models with 3-position (auto/0/1) or 5-position (auto/0/1/2/3 speed) fan switch.
- Models with or without Honeywell logo.
- LONWORKS® bus jack on all models except the low-cost T7770A1006.
- Locking cover on all models.
- Operating range 45 to 99°F (7 to 37°C).
Temperature Sensor Accuracy
T7770A-G 20K Ohm Nonlinearized Sensor: All T7770 models are equipped with a 20K Ohm nonlinear NTC temperature sensor that follows a specific temperature-resistance curve (see Fig. 1). Honeywell controllers used with the T7770 employ an algorithm that provides readings close to the actual temperature. Sensor accuracy across the range of 41 to 99°F (5 to 37°C) is better than ±0.36°F (±0.2°C). Refer to form 63-7074 for detailed nominal temperature resistance output in table form.
Figure 1: Temperature vs. resistance for nonlinear sensor. A graph showing temperature on the x-axis (30°F to 110°F / 0°C to 40°C) and resistance in K Ohms on the y-axis (10K to 80K). The curve shows resistance decreasing as temperature increases, with a point marked at 20K Ohm at 77°F (25°C).
Table 1. T7770 Wall Module Models.
| Model Number | Honeywell Logo | No Honeywell Logo | Setpoint Adjustment | Occupied/Unoccupied Button and LED | Fan Switch (3 or 5 Position) | Compatible With |
|---|---|---|---|---|---|---|
| T7770A1006 | — | — | — | — | — | Excel 600, 500, 100, 80, 20 and Excel 10 W7750A,B W7751B,D,F,H W7752A,B,C W7753 W7761 Controllers |
| T7770A2004 | T7770A2012 | — | — | — | — | |
| T7770B1004 | — | — | 55 to 85°F (10 to 35°C) | — | — | |
| T7770B1020 | — | — | ± | — | — | |
| T7770B1046 | — | — | — | — | ||
| T7770C1002 | T7770C1010 | — | 55 to 85°F (10 to 35°C) | X | — | |
| T7770C1028 | — | — | ± | — | ||
| T7770C1044 | T7770C1051 | — | — | |||
| T7770D1000 | — | — | — | — | ||
| T7770E1007 | — | — | 55 to 85°F (10 to 35°C) | X | 3 | |
| T7770E1023 | — | — | ± | |||
| T7770E1049 | — | — | ||||
| T7770F1005 | — | — | 55 to 85°F (10 to 35°C) | X | 5 | |
| T7770F1021 | — | — | ± | |||
| T7770F1047 | — | — | ||||
| T7770G1003 | — | — | — | — |
NOTE: Refer to T7770A through G Installation Instructions, 95-7538, for wall module settings and wiring diagrams. Some T7770 features may not be available with all controllers.
Communications
Except for the T7770A1006 model, these controllers feature a LONMARK® bus communications port. If necessary, the jack plug must be removed in the field, and terminals 1 and 2 wired according to the installation instructions. LONMARK® bus communication is not applicable when the wall modules are used with Excel 600/500/100/80/20 Controllers. The LONMARK® bus is insensitive to polarity, minimizing installation errors due to miswiring. The recommended wire size for the LONMARK® bus is Level IV, 22 AWG (0.34 sq.mm) plenum or non-plenum rated, nonshielded, twisted pair, solid conductor wire.
T7770B,C,E,F Setpoint Adjustment
For Wall Modules equipped with a setpoint adjustment, the controller must be programmed for the values specified in Table 2.
Table 2. Setpoint Values.
| Setpoint Value | Program Setting |
|---|---|
| 55°F | 2.773 V |
| 65°F | 2.148 V |
| 75°F | 1.345 V |
| 85°F | 0.43 V |
T7770C,D,E,F,G Wall Module Bypass Override/LED Operation
When Used With Excel 10 Controllers: The controller provides timed occupied and unoccupied temperature setpoints for the Wall Module (see Fig. 2). The bypass pushbutton is used to change the controller into the modes shown in Table 3 and Fig. 3. The override LED displays the override status of the controller.
Figure 2: LED and bypass pushbutton locations. Diagrams show two wall module types, T7770C,E,F* and T7770D,G*. Both diagrams indicate the location of the OVERRIDE LED and the BYPASS PUSHBUTTON. The T7770C,E,F* has a fan switch labeled 'auto 0 1', while the T7770D,G* has a fan switch labeled 'auto 0 1 2 3'. A note indicates that T7770C/D do not have a fan speed switch.
When Used With Excel 600/500/100/80/20 Controllers: The application engineer/programmer can configure the override and LED to operate as desired. The override (bypass) input is a dry contact, normally open, momentary digital input when the wall module does not have a fan switch. When a fan speed switch (which involves a series of resistances based on fan switch position) is present, the bypass button functions as an analog input. See Table 4 for resistances.
Table 3. Wall Module Operation.
| Pushbutton Held Down | Controller Mode | LED Status |
|---|---|---|
| 0 to 1 second | No override. | Off |
| 1 to 4 seconds | Timed occupied override. | On |
| 4 to 7 seconds | Unoccupied override. | Single blink per second |
| Longer than 7 seconds | No override. | Off |
| — | Continuous occupied override.a | Two blinks per second |
a Remote function. Generated from the network.
Figure 3: Bypass pushbutton operation. A state diagram illustrating the bypass pushbutton operation. States include NOT ASSIGNED (LED OFF), BYPASS OCCUPIED (LED ON), and UNOCCUPIED (LED BLINK). Transitions are triggered by pressing the button for specific durations (less than one second, one to four seconds, four to seven seconds, longer than seven seconds) or by BYPASS TIMEOUT.
T7770E,F,G Wall Module Fan Switch
When Used With Excel 10 FCU Controller: With the switch in the far left position, the fan operates automatically at the speed determined by the controller's temperature control algorithm. With the switch in the 0 position, the fan is off. Position 1 corresponds to fan speed 1, and so on. The wall module fan speed switch overrides the temperature control algorithm.
When Used With Excel 600/500/100/80/20 Controllers: Excel 600/500/100/80/20 Controllers can be programmed so that the fan speed switch and bypass button function as intended by the application engineer/programmer. See Table 4 for controller-programming resistances.
Table 4. Program Settings (Wall Modules with Fan Switch).
| For Switch Position | Resistance (ohms) |
|---|---|
| Auto | 11.861 K ± 119 |
| 0 | 12.686 K ± 127 |
| 1 | 13.866 K ± 139 |
| 2 | 13.04 K ± 130 |
| 3 | 14.60 K ± 146 |
| Bypass button closed | 10 K ± 100 |
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