Keypad Operation - Honeywell R7426B Product Data

Temperature controller with real time clock

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Manual (16 pages)

Table of Contents

R7426A,B,C TEMPERATURE CONTROLLER

STEP 2 ON

STEP 1 ON

4 SIGNAL SEQUENCE

OF O3/O1 OUT1/OUT2

OFF

4.5 11

6.5 13

Fig. 16. 15-stage binary on/off electric

heating and cooling.

Two Position Damper Control (R7426B,C)

If parameter OMode is 4, then the R7426B,C damper output

signal O1 operates as a two-position control output:

• When the controller mode is occupied, unoccupied or

night: O1 is 100 percent.

• When the controller mode is Off: O1 is 0 percent.

• The O2/O3 output sequence operates as heating/cooling

sequence control.

NOTE: The start-up routine must be disabled.

Analog Output (R7426C only)

Three dc output control signals are provided to control

actuators for valves, dampers, or pneumatics (through E/P

transducers).

The full output range is 0 to 12 Vdc. The control range is

common to all outputs and is software configurable to either:

2 to 10 Vdc, or 0 to 10 Vdc.

NOTE: Use the parameter ORange to configure the output.

On/Off (Fan, Pump) Output

The On/Off output (terminals 9 and 10) is provided to switch a

fan, pump, or R7426 without the Real Time Clock. See Table 8

for operation.

NOTES: The R7426A controller will switch the On/Off output

off when the following criteria are all met:

—

Parameter Ctrltyp is Hi2.

—

OAT is above 46°F.

—

O1 is 0 percent for more than 5 minutes during

any mode other than Off.

63-2564—1

STEP 15 ON

POWER

STEP 14 ON

O3/O1

89 95.5 100%

6.5 13

M17452

Table 8. On/Off Output Operation.

Freeze Protection

Active

Inactive

Controller has an adjustable delay time before switching on.

Exception: On/Off output will switch to On if NightHigh or

NightLow limits are reached.

Adjustments

Control Point / Setpoint Adjustment (CPATYP)

The control or setpoint can be adjusted using an internal or

external potentiometer connected to the CPA/SPA input (see

Technical Data). The CPA/SPA type is selected by the control

parameter CPATYP (see Technical Data).

Temperature Sensor Calibration (I01CAL, I02CAL

and I03CAL)

In case of an offset resulting from long wiring lengths, the

temperature sensor inputs (I01, I02 and I03) can be adjusted

separately using parameters I01CAL, I02CAL and I03CA.