Honeywell T775A, T775B, T775M INSTALLATION INSTRUCTIONS

T775A/B/M Series 2000 Electronic Stand-Alone Controllers

INSTALLATION INSTRUCTIONS

PRODUCT DESCRIPTION

The T775 electronic stand-alone controllers are the next generation of commercial and agricultural controls capable of remote sensing of temperature and providing switched and/or proportional outputs to various types of loads.

Five models have analog (modulating) outputs for actuator and motor control, and NEMA-4 weatherproof enclosures are available for wet environments.

IMPORTANT

Each T775A/B/M controller is an operating control, not a limit or safety control. If used in applications requiring safety or limit controls, a separate safety or limit control device is required.

Table 1. T775A/B/M Controller Configurations.

Analog

Controller

Model

T775A2009 Standard T775A1001 1 None None 1 1 NEMA 1

T775B2016 Standard N/A 2 None 1 2 1 NEMA 4X

T775B2024 Standard T775C1009 T775D1008 4 None 2 2 1 NEMA 4X

T775B2032 Standard T775A1019 T775B1000 2 None 1 2 1 NEMA 1

T775B2040 Standard T775A1027 T775A1035

T775M2006 Modulating N/A None 2 N/A 2 1 NEMA 1

T775M2014 Modulating T775G1005 T775G1013

T775M2022 Modulating N/A 2 2 N/A

T775M2030 Modulating T775E1114 T775F1022

T775M2048 Modulating T775E1015 T775E1023

All models include a digital input for use with the disable or setback option.

The modulating (analog) outputs are 4-20 mA, 0-10 Vdc, 2-10 Vdc, or Series 90 selectable.

Each floating output eliminates two SPDT relays.

These models can support a high/low modulating limit at Sensor B for temperature control at Sensor A.

Description Replaces

T775B1018 T775B1026 T775B1042

T775G1021 T775G1039

T775F1055 T775F1089

T775E1056 T775E1064 T775E1098

SPDT Relay

Outputs

4 None 2 2 1 NEMA 1

42 N/A

22 N/A

(Mod)

Outputs

Floating

Sensor

Nbr of

Sensors

Inputs

Included Enclosure

1NEMA 4X

1NEMA 1

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T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

Temperature Sensors

The controller accepts 1,097 Ohms PTC at 77° F (25° C):

• 50021579-001 – Standard sensor (included with all models except NEMA 4X models)

• T775-SENS-STRAP– Strap on sensor withwiring box

• T775-SENS-WR – Water resistant with 5 foot leads (included with NEMA 4X models)

• T775-SENS-WT – Watertight with 6 foot lead

• T775-SENS-OAT – Outdoor air temperature sensor

• C7031B2005 – 6 inch duct mount with wiring box

• C7031D2003 – 5 inch immersion sensor with wiring box (use immersion well; P/N 50001774-001)

• C7031J2009 – 12 foot duct averaging sensor with wiring box

• C7046D1008 – 8 inch duct probe with mounting flange

• C7100D1001 – 12 inch fast response, duct averaging sensor with flange

• C7130B1009 – Room mount sensor

See form 62-0265 - Temperature Sensors for the T775

Series 2000 Stand-alone Controller

Accessories

• 107324A – Bulb Holder, duct insertion

• 107408 – Heat Conductive Compound, 4 ounce

• 50001774-001 – Immersion Well, stainless steel 304, 1/2 in. threading.

Controller Dimensions

TOP

1 (25.5)

7/8 (22.5)

2 15/16 (74)

4 13/32 (112.1)

3 31/32 (101)

FRONT VIEW

1 (25.5)

4 1/16 (103.4)

7/8 (22.5)

LEFT RIGHT

1/64 (3.8)

8 5/32 (207.1)

7 23/32

2 11/16 (68.1)

(196)

7/8 (22.5)

Fig. 1. T775A/B/M Dimensions in in. (mm).

62-0254—05 2

BOTTOM

1/2 (12.4)

2 13/16 (71.8)

7/8 (22.5)

M24279

T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

BEFORE INSTALLATION

Review the “Specifications” on page 35 before installing the controller.

When Installing This Product

1. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.

2. Check ratings given in instructions and on the product to ensure the product is suitable for your application.

3. Installer must be a trained, experienced service technician.

4. After installation is complete, check out product operation as provided in these instructions.

INSTALLATION AND SETUP

The following installation procedures are typically performed in the order listed:

1. Mounting — See “Mounting” below.

2. Wiring — See “Wiring” on this page.

3. Checkout — See page 10.

4. Programming — See page 13.

5. Scheduling (optional) — See page 30.

Additional topics are:

• Temperature sensor calibration begins on page 10.

• Interface overview begins on page 11.

• Setup (for advanced options) begins on page 17.

• Summary menu begins on page 34.

• Troubleshooting begins on page 34.

MOUNTING

This section describes the mounting procedures for the controller and temperature sensor(s).

Controller Mounting

IMPORTANT

Avoid mounting in areas where acid fumes or other deteriorating vapors can attack the metal parts of the controller circuit board, or in areas where escaping gas or other explosive vapors are present.

IMPORTANT

The controller must be mounted in a position that allows clearance for wiring, servicing, and removal.

Use a screwdriver to pry out only the knockouts that you will use.

If mounting on DIN rail, be sure to remove the knockouts before mounting. See “Controller Wiring” on page 5 and Fig. 7 on page 6 for recommended knockout usage and locations. If you do not use an opened knockout be sure to cover it.

Mount the controller on any convenient interior location using the four mounting holes provided on the back of the enclosure using #6 or #8 screws (screws are not provided and must be obtained separately). Use controller dimensions in Fig. 1 on page 2 as a guide.

The controller may be mounted in any orientation. However, mounting in the orientation shown in Fig. 1 permits proper viewing of the LCD display and use of the keypad.

NEMA 4 Enclosure Mounting

For models with NEMA 4 enclosures, ensure that waterproof wire/conduit fittings are used at the knockouts for all wiring attachments. Refer to Fig. 7 on page 6 for knockout locations.

IMPORTANT

For NEMA 4 enclosures, be sure to cover and seal all unused open knockouts.

Temperature Sensor(s) Mounting and Location

Temperature sensors may be located up to 1,000 feet (304 m) from the T775A/B/M controller. Refer to Table 3 on page 10 for calibration guidelines.

The sensors may be mounted on a wall or panel for sensing space temperature, strapped to a pipe or inserted in an immersion well (see Fig. 2) for hot or cold water sensing, or taped to a standard cap or bulb holder for duct air sensing. To prevent moisture or condensation entering the sensor through the lead wire holes, mount the sensor with the lead wires exiting the bottom of the sensor.

NOTES:

1. The included sensor is not designed for very wet applications. For immersion applications, an immersion well is used.

2. Heat conductive compound must be used in immersion wells.

3. Refer to “Temperature Sensors” on page 2 for this type of installation.

1/2 NPT

USE HEAT

CONDUCTIVE

COMPOUND

IMMERSION WELL

M24470

SENSOR

PLACED IN WELL

Fig. 2. Sensor Inserted in Immersion Well.

NOTE: Multiple sensors may be parallel-series wired to

sense average temperatures in large spaces. Refer to Fig. 3 on page 4.

WIRING

All wiring must comply with applicable electrical codes and ordinances, or as specified on installation wiring diagrams. Controller wiring is terminated to the screw terminal blocks located inside the device.

The remainder of this section describes the temperature sensor wiring and the T775A/B/M controller wiring.

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T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

Wiring Connections Access

To access the wiring connections, remove the two screws on the left side of the enclosure and gently swing open the top. Be careful to not stress the ribbon cables that connect the keypad and LCD display to the controller circuit board.

Temperature Sensor Wiring

CAUTION

Electrical Shock Hazard. Can short equipment circuitry.

Make sure that metal tube of sensor does not short against T terminals in wall-mounted case.

IMPORTANT

Poor wiring practices can cause erratic readings from the sensor. Avoid the following to ensure proper operation:

• Do not route the temperature sensor wiring with building power wiring.

• Do not locate the temperature sensor wiring next to control contactors.

• Do not locate the temperature sensor wiring near electrical motors.

• Do not locate the temperature sensor wiring near welding equipment.

• Make sure good mechanical connections are made to both the sensor and the controller.

• Do not mount the sensor with the lead wire end pointing up in an area where condensation can occur.

If any of the above conditions cannot be avoided, use shielded cable.

NOTE: Each T775 controller must be wired to its own

sensor(s). However, a benefit of the T775 controller’s accuracy is that there is no more than a 2° F (-7° C) differential between any two T775 controllers.

Multiple Parallel Sensors

Multiple sensors can be parallel-series wired to sense average temperatures in large spaces. To maintain control accuracy, the number of sensors to be parallelseries wired must be of the n 16, etc.) (See Fig. 3).

SENSORS

TO T775 CONNECTIONS (SENSOR A) OR (SENSOR B).

power (for example, 4, 9,

M24471

Fig. 3. Parallel-Series Wiring of Sensors.

Temperature Sensor Wire Type and Size

Temperature sensors use standard AWG 18/2 unshielded wire. For cable runs greater than 25 feet or where electrical interference may be a problem, shielded cable is recommended (See Fig. 4).

Refer to “Temperature Sensor Calibration” on page 10 for wire size selection where cable runs are longer than 25 feet.

T T

SENSOR A AND SENSOR B TERMINAL WIRING IS POLARITY INSENSITIVE.

SENSOR A

SENSOR B

SHIELDED CABLE

Fig. 4. Sensor Wiring — Showing Shielded Cable Connection to Sensor A.

62-0254—05 4

SHIELDED CABLE

NOTE: SHIELDED CABLE MUST BE CONNECTED TO AN EARTH GROUND. HOWEVER, DO NOT GROUND SHIELDED CABLE AT SENSOR END.

NOTE: TO MINIMIZE NOISE PICKUP, MAKE SENSOR CONNECTION FROM SHIELDED CABLE AS CLOSE AS POSSIBLE TO SENSOR BODY.

SENSOR

M24472

T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

Controller Wiring

WARNING

Electrical Shock Hazard. Can cause severe injury, death or property damage.

Disconnect power supply before beginning wiring, or making wiring connections, to prevent electrical shock or equipment damage.

CAUTION

Do not use 24 Vac power to power any external loads if 120 Vac or 240 Vac is used to power the T775A/B/M controller.

CAUTION

A separate earth ground is required.

Equipment damage can result if the earth ground is not connected. See Fig. 5 and Table 2 on page

CAUTION

Equipment Damage Hazard. Electrostatic discharge can short equipment circuitry.

Ensure that you are properly grounded before handling the unit.

See Fig. 7 on page 6 for locating the appropriate power input, remote sensors input, low voltage, contact closure, and load output terminals.

Access to the terminals can be gained through standard conduit knockouts (A through E in Fig. 7 on page 6) located around the perimeter of the enclosure:

• Knockouts A and B should be used only for sensor and low-voltage wiring.

• Knockouts C, D, and E can be used to gain access to the load relay output terminals and 120/240 Vac power wiring.

Controller Wiring Method

Wire the sensors and outputs, then wire the power connection.

Each terminal can accommodate the following gauges of wire:

• Single wire – from 14 AWG to 22 AWG solid or stranded

• Multiple wires – up to two 22 AWG stranded

For 24, 120, or 240 Vac power connections:

• Single wire – from 14 to 18 AWG solid or stranded

Prepare wiring for the terminal blocks, as follows:

1. Strip 1/2 in. (13 mm) insulation from the conductor.

2. Cut a single wire to 3/16 in. (5 mm). Insert the wire

in the required terminal location and tighten the screw.

3. If two or more wires are being inserted into one terminal location, twist the wires together a minimum of three turns before inserting them to ensure proper electrical contact.

4. Cut the twisted end of the wires to 3/16 in. (5 mm) before inserting them into the terminal and tightening the screw.

5. Pull on each wire in all terminals to check for good mechanical connection.

1. STRIP 1/2 IN. (13 MM)

FROM WIRES TO BE ATTACHED AT ONE TERMINAL.

1/2 (13)

NO HIGH VOLTAGE. CLASS 2 WIRING ONLY.

EARTH GROUND TERMINAL MUST BE CONNECTED

TO CONDUIT CLAMP LOCALLY.

Fig. 5. Earth Ground.

IMPORTANT

Poor wiring practices can cause erratic readings from the sensor. To ensure proper operation, ensure that good mechanical connections are made to both the sensor and the controller.

IMPORTANT

When wiring the input power, only one source of power can be applied to the T775A/B/M controller (24 Vac or 120 Vac or 240 Vac).

M24296

2. TWIST WIRES

TOGETHER WITH PLIERS (A MINIMUM OF THREE TURNS).

3. CUT TWISTED END OF WIRES

TO 3/16 IN. (5 MM) BEFORE INSERTING INTO TERMINAL AND TIGHTENING SCREW. THEN PULL ON EACH WIRE IN ALL TERMINALS TO CHECK FOR GOOD MECHANICAL CONNECTION.

M24473

Fig. 6. Attaching Two or More Wires at Terminal

5 62-0254—05

Blocks.

T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

Controller Wiring Details

The wiring connection terminals are shown in Fig. 7 and are described in Table 2.

See Fig. 8 – Fig. 20 beginning on page 6 for typical T775A/B/M wiring applications.

KNOCKOUT A

– +

KNOCKOUT E

T T

MOD 1

MOD 2

DIGITAL

INPUT

KNOCKOUT B

POWER

24 VAC

OUTPUT

RELAY 4

OUTPUT

RELAY 1

KNOCKOUT C

SENSORS A AND B USE THE TWO TT CONNECTIONS AND ARE POLARITY INSENSITIVE.

FOR MOD 1 AND MOD 2 CURRENT (mA) OR VOLTAGE (VDC) OUTPUT, USE SIGNAL (+) & COMMON (-). FOR MOD 1 AND MOD 2 SERIES 90 OUTPUT, USE W, R, & B.

A SEPARATE EARTH GROUND IS REQUIRED FOR ANY POWER

SOURCE (24, 120, OR 240 VAC).

B R W

– +

120

COM

240

SENSOR A

SENSOR B

OUTPUT RELAY 3

POWER 120/240 VAC

OUTPUT RELAY 2

KNOCKOUT D

M24474

Table 2. Description of Wiring

Terminal Connections. (Continued)

Connection Terminal Label Description

Input

DI + - Digital Input (dry

contact)

24 Vac Power

24V + + 24 Vac Hot

Common C 24 Vac Common

Ground

Earth Ground

120 or 240 Vac Power

120 Vac 120 120 Vac Power

Common COM Common

240 Vac 240 240 Vac Power

For Series 90 connections, you must insert a 340 Ohm resistor across terminals R and W. Refer to Fig. 17 on page 8. The resistor is included with the controller.

A separate earth ground is required for all installations regardless of the power source (24, 120, or 240 Vac). Refer to Fig. 5 on page 5.

WIRING APPLICATIONS (EXAMPLES)

Fig. 8 – 20 illustrate typical controller wiring for various applications.

SENSOR A

T T

Fig. 7. T775A/B/M Terminal and Feature Locations.

NOTE: Refer to Table 1 on page 1 for the specific

configuration of sensors and outputs supported by the model you are installing.

NOTE: For NEMA 4 enclosures, use waterproof fittings

for wiring/conduit connections at knockouts.

Table 2. Description of Wiring

Terminal Connections.

Connection Terminal Label Description

Sensors

Sensor A T T Temperature Sensor;

Sensor B

polarity insensitive

Outputs

Relay 1 Relay 2 Relay 3 Relay 4

Mod 1 + - (Vdc or mA)

Mod 2

62-0254—05 6

NO COM NC

W R B (Series 90)

120-240 Vac Relay Output

Modulating Output

(HOT)

Fig. 8. Wiring for Two-Stage Control – 24 Vac Input

24 VAC

LOAD 1

LOAD 2

COM

and 24 Vac Load.

COM

M24475A

T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

SENSOR A

T T

(HOT)

Fig. 9. Wiring for Four-Stage Control – 24 Vac Input

24 VAC

LOAD

COM

LOAD

COM

LOAD

COM

LOAD

and 24 Vac Load.

SENSOR A

T T

LOAD 4

LOAD 1

120

COM

M24476

FOR 240 VAC LOAD, CON NECT TO 240 TERMINAL .

Fig. 11. Wiring for Four-Stage Control with 120 or 240

Vac (120 Vac Input and 120 Vac Load Shown).

120V COM

240

SENSOR A

LOAD

M24478A

120/240 VAC LINE

COM

120V COM

POWER SUPPLY

120

240

COM

LOAD 2

COM

L1 ( HOT )

LOAD 1

FOR 240 VAC LOAD, CON NECT TO 240 TERMINAL .

Fig. 10. Wiring for Two-Stage Control with 120 or 240

Vac (120 Vac Input and 120 Vac Load Shown).

M24477A

BARCODE

CLOSE RELAY TO DRIVE DEVICE OPEN. RELAY 1 SHOWN.

(RELAYS 1 AND 3 ARE USED FOR OPEN).

CLOSE RELAY TO DRIVE DEVICE CLOSED. RELAY 2 SHOWN.

(RELAYS 2 AND 4 ARE USED FOR CLOSE).

THE RELAYS MUST BE WIRED IN PAIRS WITH RELAYS 1 AND 2 BEING THE FIRST PAIR, AND RELAYS 3 AND 4 BEING THE SECOND PAIR.

Fig. 12. Wiring for Floating Output (Relay 1 and Relay

2 Pair Shown).

COM

DEVICE

OPEN

COM

M24479

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T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

ML7984 ACTUATOR

T1 T2 B WR

POWER

OUTPUT

MODULATING OUTPUT TERMINAL (MOD 1)

Fig. 13. Wiring for ML7984 Valve Actuator

(Using 4 to 20 mA Signal).

DIGITAL

INPUT

–

W B

–

M24482

Fig. 14. Wiring for Digital Input (Dry Contact).

HONEYWELL MODUTROL MOTOR WITH 4-20 mA MODULATING INPUT

T1 T2

–

POWER

OUTPUT

MODULATING OUTPUT TERMINAL (MOD 1)

USE SEPARATE TRANSFORMER FOR T775R WHEN USING 24 VAC.

Fig. 15. Wiring for Mod Motor or Direct Coupled

Actuator with 4 to 20 mA Control Input.

HONEYWELL MODUTROL MOTOR WITH VOLTAGE CONTROL INPUT

T1 T2 C R

–

W B

–

HONEYWELL ELECTRONIC SERIES 90 MODUTROL MOTOR

B R

–

B R

–

M27228

T1 T2 B WR

POWER

OUTPUT

MODULATING OUTPUT TERMINAL (MOD 1)

TO VERIFY OUTPUT, TEST OPEN CIRCUIT VOLTAGE BETWEEN THE MOD 1 TERMINALS W AND R.

- MINIMUM (DRIVE CLOSED) SIGNAL LESS THAN 0.17 VDC

- MAXIMUM (DRIVE OPEN) SIGNAL IS GREATER THAN 1.7 VDC

USE SEPARATE TRANSFORMER FOR T775R WHEN USING 24 VAC.

INSERT 340 OHM RESISTOR (INCLUDED) ACROSS TERMINALS R AND W.

Fig. 17. Wiring for Series 90 Modutrol Motor Control.

MINIMUM POSITION POTENTIOMETER (Q209)

W R B

–

W B

–

M24481

HONEYWELL ELECTRONIC SERIES 90 MODUTROL MOTOR

T1 T2 B WR

POWER

OUTPUT

MODULATING OUTPUT TERMINAL (MOD 1)

USE SEPAR ATE TR ANSFORMER FOR T 775R WHEN USING 24 VAC.

A 250 OHM RES ISTOR PROVIDES 40% AUTH ORITY WHEN

USING A 150 OH M MINIMUM POSIT ION POTENTIOME TER.

INSERT 340 OHM RESISTOR (INCLUDED) ACROSS TERMINALS R AND W.

Fig. 18. Wiring for Changeover Relay and

Minimum Position Potentiometer Used

with Series 90 Modutrol Motors.

SPDT CHAN GEOVER (H205 OR H70 5)

M24484

M24485

POWER

OUTPUT

MODULATING OUTPUT TERMINAL (MOD 1)

USE SEPARATE TRANSFORMER FOR T775R WHEN USING 24 VAC.

Fig. 16. Wiring for Mod Motor or Direct Coupled

Actuator with 0 to 10 Vdc Control Input.

–

W B

–

M24483

62-0254—05 8

T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

M9184 OR M9185 MODUTROL MOTOR

–

W B

–

MODULATING OUTPUT TERMINAL (MOD 1)

POWER SUPP LY. PROVIDE DISC ONNECT MEANS AN D OVERLOAD PROTECTION A S REQUIRED.

USE A 1300 OH M RESISTOR FOR TWO MOTO RS, 910 OHM RESISTOR FOR TH REE MOTORS.

THE 407EAU R ESISTOR KIT, WHICH IS SH IPPED WITH THE M9184 A ND M9185 MOTORS, INCLUDES BOTH RESISTORS.

INSERT 340 OHM RESISTOR (INCLUDED) ACROSS TERMINALS R AND W.

M9184 OR M9185 MODUTROL MOTOR

Fig. 19. Wiring for Three Series 90 Modutrol Motors.

(HOT)

M24486

L1 (HOT) L2

MINIMUM

–

W B

–

POWER

24 VAC

MODULATING OUTPUT TERMINAL (MOD 1)

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

UP TO SIX SIMILAR MOTORS CAN BE CONNECTED IN UNISON.

USE RESISTOR BETWEEN R AND B ON THE MOD 1 TERMINAL: 1300 OHMS FOR TWO MOTORS; 910 OHMS FOR THREE MOTORS (4074EAU KIT).

IF COMMON TRANSFORMER IS USED, ALL MOTORS MUST BE IN PHASE. CONNECT THE SAME TRANSFORMER LEAD TO T1 ON EACH MOTOR,

CONNECT THE OTHER TRANSFORMER LEAD TO T2 ON EACH MOTOR.

USE TEMPERATURE CONTROLLER SUCH AS H205 OR H705, OR T675A FOR CHANGEOVER CONTROL.

AUTHORITY OF MINIMUM POSITION POTENTIOMETER, IF USED, INCREASES WITH THE NUMBER OF MOTORS IN PARALLEL. WITH ONE MOTOR,

50% STROKE; WITH TWO MOTORS, 100% STROKE; WITH THREE MOTORS, 100% STROKE WITH 1/3 OF FULL POTENTIOMETER ROTATION.

REVERSING THE B AND W TERMINALS ON ONE OR MORE MOTORS WILL NOT AFFECT CONTROL PERFORMANCE ON THE OTHER MOTORS. THE SYSTEM CAN BE CONFIGURED TO HAVE SOME MOTORS BE REVERSE ACTING AND OTHER MOTORS BE DIRECT ACTING.

USE SEPARATE TRANSFORMER FOR T775 WHEN POWERING FROM 24 VAC.

THE SYSTEM IS SHOWN CONNECTED FOR COOLING. FOR HEATING, REVERSE THE W AND B LEADS OF THE MODULATING OUTPUT ON THE

T775 CONTROLLER.

Fig. 20. Wiring for Unison Control of M9184 or M9185 Modutrol IV Motor Using One Minimum Position

Potentiometer for All Motors.

POSITION POTENTIOMETER (Q209/S963)

CHANGEOVER

CONTROLLER

M9184 OR M9185 MODUTROL MOTOR

M24487

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T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

CHECKOUT

Inspect all wiring connections at the controller terminals, and verify compliance with the installation wiring diagrams.

WARNING

Electrical Shock Hazard. Can cause severe injury, death or property damage.

Disconnect power supply before beginning wiring or making wiring connections, to prevent electrical shock or equipment damage.

If any wiring changes are required, first be sure to remove power from the controller before starting work. Pay particular attention to verifying the power connection (24, 120, or 240 Vac).

After the controller is installed and wired, apply power.

Power Loss

The date and time settings are retained for 24 hours after a power outage. After a power loss of more than 24 hours, the date and time settings may need to be reentered. All other settings are stored permanently.

Temperature Sensor Calibration

As wire length increases, resistance increases and thus the temperature reading increases. If necessary, calibrate the sensor input by reducing the value by the amount shown in the Table 3. For example, a wire run with 18 gauge wire of 1,000 feet, requires a calibration offset of

-6.0° F (-21° C).

IMPORTANT

If the calibration value in the table exceeds the controller’s calibration limits of +/-10° F (+/-6° C), you must use a heavier gauge wire.

For example, with a wire run of 1,000 feet you must use 20 AWG wire or heavier in order to calibrate for wire loss within the limits of the controller.

See “2.2.2.2. CALIBRATE (the sensor)” on page 18 for the instructions to enter the calibration value.

Table 3. Temperature Sensor Calibration for

Resistance Loss Due to Wire Length.

AWG

Rating mΩ/ft

Temperature Offset in

200 ft 500 ft 1,000 ft

°F (Foot)

14 2.5 0.46 1.14 2.28

16 4.0 0.72 1.82 3.64

18 6.4 1.16 2.90 5.82

20 10.2 1.86 4.64 9.28

22 16.1 2.92 7.32 14.64

AWG

Rating mΩ/m

Temperature Offset in

°C (Meter)

100 m 200 m 300 m

14 8.3 0.44 0.86 1.30

16 13.2 0.68 1.38 2.06

18 21.0 1.10 2.18 3.28

20 33.5 1.74 3.48 5.22

22 52.8 2.74 5.48 8.22

This is the distance from the controller to the sensor (already accounts for round trip distance).

Fig. 21 shows how sensor resistance varies with temperature for a sensor having a positive temperature coefficient (PTC) of 2.1 Ohms per degree F (3.85 Ohms per degree C).

RESISTANCE (OHMS)

1489

1403

1317

1231

1145

1059

973

887

801

-40 -20 -10-30

POSITIVE TEMPERATURE COEFFICIENT (PTC) OF 2.1 OHMS PER °F

20 40 60 80 100 120 140 160 180 200 220

0-20-40

1097 ± 0.08 OHMS AT 77°F (25°C)

0 10 20 30 40 50 60 70 80 90 100

TEMPERATURE (DEGREES)

250

110

120

M24304

Fig. 21. Sensor Resistance vs. Temperature.

°F

°C

62-0254—05 10

T775A/B/M SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

INTERFACE OVERVIEW

The T775A/B/M controllers use an LCD panel and 6-button keypad to provide status information and permit user input of the programming, setup, and scheduling parameters.

The following figure describes the display areas of the LCD and the keypad.

HOME RELAYS 1 2 3 4 ON

SENSORS

SENSOR A

SENSOR B

MOD1 40% MOD2 60% DI ON

home menu

Fig. 22. LCD Display - Home Screen And Keypad.

Menu Area – On the home screen, the LCD displays the

configured relays and whether they are active. In Program, Setup or Schedule mode, the LCD displays the current menu selection and its order within the menu hierarchy.

Data Area – On the home screen, the LCD displays the sensors and outputs status. In Setup or Program mode, the LCD displays menu choices, parameter selections, and data values.

Lock Icon – The icon indicates the MENU button is locked and prevents access to the Setup and Program menus.

NOTE: Pressing and holding the HOME and MENU

buttons simultaneously for five seconds locks/ unlocks the MENU button.

6-Button Keypad – The keypad is used to access the menus and enter values (See “Using the LCD Panel Interface”).

Using the LCD Panel Interface

The 6-button keypad is used to move through the menus and enter or change parameter values.

Home Button

Pressing the HOME button at any time exits the current Programming or Setup display screen and returns to the home screen as shown in Fig. 22 and Fig. 23.

MENU AREA

DATA AREA

LOCK ICON

6 BUTTON KEYPAD

M24488

Menu Button

• Pressing the MENU button always displays the Program menu. If you are in Setup mode, you exit setup and return to the Program menu.

• Pressing and holding the MENU button for five seconds leaves the current screen and displays the Setup menu.

Left and Right Arrow Buttons (W and X)

Use these buttons to move backward (W) and forward (X) through the Program and Setup menus.

Up and Down Arrow Buttons (S and T)

Use these buttons to move your selection up and down through a menu or list.

• When the desired item is highlighted, you press the X arrow button to display that item’s content.

• When a value is displayed (e.g. 70° F), the up and down arrows increase and decrease the value.

NOTE: Once you select an item from a list or enter a

value, pressing the W or X or HOME button accepts your selection or value and stores it in the controller’s memory.

Home Screen

In the normal run state, the LCD home screen displays the current sensed temperatures, the modulating outputs status, the active status of the output relays, and error and status codes.

Active relays are indicated by the small black square () just below the relay number. Fig. 23 shows the home screen with relays 1, 2, and 4 energized.

Pressing the W and X buttons from the home screen cycles through each modulating output that is paired with the sensor it controls and the active output relays.

HOME RELAYS 1 2 3 4 ON

SENSORS

SENSOR A

SENSOR B

MOD1 40% MOD2 60%

DI ON

Fig. 23. LCD Display - Home Screen Displaying

Sensors, Active Relays, and Mod Outputs.

NOTE: The modulating output home screen and the

relay home screen do not dynamically update the active relay status, sensor values, and modulating output percentages. The information is a snapshot taken when you press the W or X button to display the screen.

IMPORTANT

After four minutes of inactivity (no buttons pressed), the LCD display reverts to the home screen display.

HOME RELAYS 1 2 3 4 ON

MOD 1 40%

COOL SETPOINT

SENSOR A

MOD1 40% MOD2 60%

DI ON

HOME RELAYS 1 2 3 4 ON

REL 1 ON

HEAT SETPOINT

SENSOR A

RT 12345 HRS

MOD1 40% MOD2 60%

DI ON

M24489

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