R7426A,B,C TEMPERATURE CONTROLLER WITH AND WITHOUT REAL-TIME CLOCK

Programming Holiday Schedule (with RTC, only)

The holiday schedule programming is used to program each day of the year (01.01 ... 31.12.) as a holiday (day type = H1, H2 or H3) or as a normal day (day type = H0 is default).

Pushing the + or - button during the first step of the holiday programming (see Fig. 16) toggles between all programmed holidays (≠ H0) and displays them (type and date).

If none of the 365 days of a year is programmed to be a holiday, the actual date is displayed, marked as normal day (H0).

Pushing the SET button selects the displayed holiday and enters the adjustment for date and day type.

To program a new holiday, select any holiday, adjust date (and holiday type if necessary) and confirm the changes by pushing the SET button. To reset a holiday to normal day, day type H0 has to be set for the specific day.

Pushing the SEL button returns to the selection mode, ignoring adjustments which have not been confirmed by the SET button.

 

TO

 

OR

TOGGLE/DISPLAY

 

PROGRAMMED

 

 

 

 

HOLIDAY

We

OR

TO ADJUST

 

MONTH

 

 

 

 

 

Sa

OR

TO ADJUST

 

DAY

 

 

 

 

 

Th

OR

TO ADJUST

 

DAY TYPE (H0,

 

 

H1, H2, OR H3)

We

 

 

Fig. 16. Holiday schedule programming

Interpreting Error Messages

Different analog input errors can be identified by the controller (Error handling). The defective analog input (T1, T2, T3 or Xwrh) will be displayed in the standard display mode (see Fig. 17) after the corresponding value is selected.

NOTE: For the external CPA/SPA potentiometer input, no error message is indicated if the potentiometer or wiring is defective. In this case, for control point or setpoint calculation, the following values are used:

•for CPATYP 0, 1 or 2 ⇒ CPA value = 0

•for CPATYP 3 ⇒ SPA value = control parameter W1

 

DISPLAY SHOWN IF NO SENSOR

DISPLAY SHOWN AFTER ERROR

 

 

IS CONNECTED DURING POWER-UP

IDENTIFICATION DURING OPERATION

STANDARD

°C % rh

°C % rh

STANDARD

 

 

DISPLAY

 

 

DISPLAY

AND

: MAIN TEMPERATURE SENSOR T1 IS DEFECTIVE

AND

: LIMITATION OR CASCADE TEMPERATURE SENSOR T2 IS DEFECTIVE

AND

: COMPENSATION TEMPERATURE SENSOR T3 IS DEFECTIVE

SPACE AND

: ERROR OF HUMIDITY DEVIATION INPUT XWrh

 

TEMPERATURE DISPLAY IN °C

 

HUMIDITY DEVIATION DISPLAY IN % rh

 

Fig. 17. Error handling

 

 

A

B

 

 

PUSH

PUSH UNTIL

STANDARD

°C

SIMULTANEOUSLY

NEEDED

FOR APPROX.

VALUE IS

DISPLAY

 

 

2 SEC

DISPLAYED

MODE

 

 

PARAMETER

 

 

 

 

 

 

ADJUSTMENT

 

 

 

MODE

 

 

°C

 

°C

PARAMETER

 

 

 

SELECTION

 

 

 

MODE

 

PARAMETER

 

 

°C

°C

 

 

SELECTION

 

 

 

MODE

 

 

 

B

A

THIS EXAMPLE DESCRIBES THE ADJUSTMENT OF THE

COMPENSATION CHANGEOVER POINT Wcomp (P03).

Fig. 18. Adjustment example

EN1B-0203GE51 R0507C

18

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Honeywell R7426B, R7426A, R7426C dimensions Interpreting Error Messages, Programming Holiday Schedule with RTC, only
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R7426C, R7426A, R7426B specifications

Honeywell's R7426 series comprises three advanced models: R7426B, R7426A, and R7426C. These devices are designed to optimize control for HVAC applications, emphasizing energy efficiency, ease of use, and superior control capabilities. Each model incorporates unique features and technologies catering to specific system requirements while maintaining common foundational characteristics.

The R7426B is engineered with a microprocessor-based control system, allowing for precise temperature management across varied environments. It supports a range of heating and cooling applications, making it versatile in both residential and commercial settings. The unit boasts dual-stage heating and cooling capabilities, ensuring optimal comfort by allowing for gradual temperature changes. It also includes an easy-to-read LCD display for user-friendly navigation and parameter adjustments.

R7426A enhances functionality with additional communication technologies. This model incorporates Honeywell's proprietary communication protocols, enabling seamless connection with smart thermostats and home automation systems. This ensures users can monitor and control their HVAC systems remotely, leading to enhanced energy management and convenience. R7426A also includes advanced diagnostic capabilities that simplify troubleshooting and maintenance processes.

R7426C further extends the capabilities of the series by integrating state-of-the-art sensors for real-time environmental monitoring. These sensors continuously track indoor air quality parameters such as humidity and particulate matter levels, allowing for immediate adjustments to maintain optimal indoor conditions. The model is also equipped with smart algorithms that learn user preferences over time, automatically adjusting settings to enhance comfort and efficiency.

Common features across the R7426 series include robust construction for long-lasting performance and compatibility with a wide range of HVAC systems, including heat pumps and conventional heating systems. Each model supports programmable settings, enabling users to create schedules that align with their unique lifestyle or business needs. Safety features, including freeze protection and delay timers, are integrated to safeguard against potential system failures.

Overall, the Honeywell R7426B, R7426A, and R7426C models represent a significant advancement in HVAC control technology. With their focus on efficiency, automation, and user-centric design, these devices help users achieve optimal climate management in their spaces while minimizing energy consumption. Whether for residential comfort or commercial efficiency, these models stand out as reliable solutions in the HVAC market.
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