Honeywell R7426C, R7426B SPECIFICATION DATA

MicroniK 200

Fig. 1. Temperature controller

Fig. 2. LC Display

R7426B,C

TEMPERATURE CONTROLLER WITH REAL-TIME CLOCK

SPECIFICATION DATA

GENERAL

The R7426B,C temperature controllers cover all space and/or discharge air temperature applications within the specified control range of 0...50°C (LOw range) requiring sequence operation of heating, mixed air damper or energy recovery system and cooling with optional outside air temperature compensation reset of the main setpoint. The controllers can be configured to perform space or discharge air or spacedischarge air temperature cascade control with limit control.

For special higher temperature control applications, the control range 0...130 C (HI range) can be selected.

FEATURES

Weekly time schedule with up to six switching points per day

Automatic daylight saving time change

Four different operating modes: Comfort, Standby, Night, and OFF

Yearly holiday programming in advance

Three types of holiday schedules

Self-adaptive optimum start program for room control system

Night cycle program

Order Numbers

Order-No.	Controller Description
R7426B2012	Temperature controller with integrated
	real time clock (RTC), Plant/System
	ON/OFF output, and three 3-position
	floating outputs. The controller offers the
	choice of selectable different output
	sequence operations and output signals
	suitable to drive solid-state relays or step
	relays.
R7426C2010	Temperature controller with integrated
	real time clock (RTC), Plant/System
	ON/OFF output, and three analog
	outputs. The controller offers selection of
	different output sequence operations.

EN0B-0301GE51 R0104

R7426B,C TEMPERATURE CONTROLLER

TECHNICAL DATA

General	Electronic		8-bit microcontroller, 10-bit A/D converter, EEPROM, and LC
			display
	Power supply		24 Vac +10...-15%, 50/60 Hz
	Power consumption		3 VA + Actuator power requirements
	Control range		0...50°C
	Battery		Type CR2032 (life time 8 years)
Temperature	T1		Main temperature sensor			accuracy 0.5 K
Inputs	T2		Cascade temperature sensor			excluding
	T3		Compensation temperature sensor			sensor
Sensor type1)	Automatic identification of sensor type		Temperature range		Characteristics2)
	Pt 1000		-30....+130 C		1000 τ at 0 C
	BALCO 500		-30....+130 C		500 τ at 23.3 C
	NTC 20kτ		-30....+85 C / -30....+130 C1)		20 kτ at 25 C
CPA/SPA-Input1)			CPA/SPA range		Sensor & CPA/SPA types
	CPATYP 0		CPA: 5 K		internal
	CPATYP 1 (953...1053 τ)		CPA: 5 K		T7412B1016 (Pt 1000)
	CPATYP 2 (0...100 kτ)		CPA: 5 K		T7412B1057 (Pt 1000)
					T7412C1030 (Pt 1000)
					T7412B1008 (NTC 20kτ)
					T7412C1006 (NTC 20kτ)
	CPATYP 3 (10...20 kτ)		SPA: 15...30 C		T7412B1024 (BALCO 500)
					T7412B1040 (Pt 1000)
	CPATYP 4 (0...10 kτ)		CPA: 5 K		HCW 23 (setpoint wheel
					printed with +/- 5 K)
	CPATYP 5 (0...100 kτ)		SPA: 15...30 C		43193982-001
	CPATYP 6 (0...100 kτ)		SPA: 0...50 C or 0...130 C		43193982-001
Analog input	Humidity deviation (Xwrh)		-5...+5 Vdc, 200 mV / %rh
Digital inputs			Mode		Potential free contact
	Occupancy		unoccupied		open > 40 kτ
			occupied		closed < 100 τ
	Freeze protection input		freeze protection operation		open > 40 kτ
			normal operation		closed < 100 τ
Outputs	ON/OFF output		OFF / ON
	TRIAC outputs			Floating1)		max. load
			2, 3, 4, 6 or 15-stage1)			450 mA at
				ON (24 Vac) / OFF (0 Vac)		24 Vac per
				Pulse-width modulation1) 0...100%		output
				based on run time
	Analog outputs on controller R7426C		Control range1) 0/2...10 Vdc (0...100%)			max. load
			full range 0...12 Vdc			1.2 mA at
						12 Vdc
Ambient limits	Operating temperature		0...50°C (0...122 F)
	Transport and storage temperature		-35...+70°C (-31...+158 F)
	Relative humidity		5...95%rh non-condensing
Safety	Protection class		II as per EN60730-1
	Protection standard		IP30 or IP40 (front panel mounting) as per EN60529
Housing	Dimensions (H x W x D)		105 x 152 x 37 mm
	Weight		250 g
	Mounting		Front door, back panel, wall, or rail
Connections	Connection terminal		terminals max. 1 x 1.5 mm2
1) Selectable	2)	same sensor type must be used for T1, T2, and T3

EN0B-0301GE51 R0104

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R7426B,C TEMPERATURE CONTROLLER

CONTROL AND CONFIGURATION PARAMETER

Control Parameter		Parameter Description		Setting				Reso-	Unit
								lution
No.	Name			Low		High	Default
P.01	W1	Main setpoint for input T1		0		50	21	0.5	C
P.02	Wlim	Limit setpoint (low or high) for input T2		5		50	16	1	C
P.03	Wcomp	Compensation changeover point for input T3		-5		40	20	1	C
P.04	Wi	Winter compensation authority		-350		+350	0	2	%
P.05	Su	Summer compensation authority		-100		+100	0	1	%
P.06	Wcas	Submaster or cascade setpoint		OFF, 0		50	20	0.5	C
P.07	Rcas	Cascade reset span adjustment		0		40	10	0.5	K
P.08	Xp1	Throttling range (main control loop) T1		0.5		40	2	0.5	K
P.09	Xp2	Throttling range (cascade control loop) T2		0.5		40	10	0.5	K
P.10	Xpc	Cooling throttling range for sequence control		OFF, 1		40	3	0.5	K
P.11	Xph	Heating throttling range for sequence control		1		40	6	0.5	K
P.12	tr11)	Reset time (main control loop) T1		OFF, 20 s		20min	OFF	10/0.5	sec/min
P.13	tr21)	Reset time (cascade control loop) T2		OFF, 20 s		20min	OFF	10/0.5	sec/min
P.14	MINPOS	Minimal pos. for air damper actuators		0		50	20	1	%
P.15	Ystart	Start point for mid range shift of output Y1		-20		+20	0	0.5	K
P.16	SOFFS	Offset of main setpoint in Standby mode		0		10	2	0.1	K
P.17	T1Cal	Calibration of temperature sensor T1		-20		+20	0	0.1	K
P.18	T2Cal	Calibration of temperature sensor T2		-20		+20	0	0.1	K
P.19	T3Cal	Calibration of temperature sensor T3		-20		+20	0	0.1	K
P.20	RetOffs	Return air offset to simulate exhaust air cond.		OFF, 0		5	OFF	0.1	K
P.21	RuntimeY1	Actuator run time for output Y1		6		180	60	1	sec
P.22	RuntimeY3	Actuator run time for output Y3		6		180	60	1	sec
P.23	RuntimeY2	Actuator run time for output Y2		6		180	60	1	sec
P.24	NightLow	Night low limit against temperature extremes		OFF, 8		19	OFF	1	C
P.25	NightHigh	Night high limit against temperature extremes		OFF, 21		40	OFF	1	C
P.26	NOFFS	Offset of main setpoint in Night mode		0		30	5	0.1	K
Config. Parameter		Values						Default	Unit
No.	Name
C.01	DIR/REVY1	Dir, Rev (R7426C, only)						Dir
C.02	DIR/REVY3							Dir
C.03	DIR/REVY2							Dir
C.04	Ctrltyp2)	Lo = 0...50°C (factory preset), Hi1 = 0...130°C, Hi2 = 0...130°C
C.05	CPATYP	0 = internal (default), 1 = 5 K (953...1053 τ), 2 = 5 K (0 τ...100kτ),						0
		3 = 15 … 30 C (10...20 kτ), 4 = 5 K (0...10 kτ),
		5 = 15 … 30 C (0...100 kτ), 6 = 0...50 C or 0...130 C (0...100 kτ)
C.06	YRange	0 = 2 … 10 Vdc , 1 = 0 … 10 Vdc (R7426C, only)						1
C.08	Y1Mode	0= floating, 1= 2 stage ON/OFF, 2= 3 stage ON/OFF, 3 = pwm, 4 = unconfig.						4
C.09	Y3Mode							4
		(safe state is configured prior to controller's start-up) (R7426B, only)
C.10	Y2Mode							4
C.11	YMode	0: Y1 = D, Y2 = C, Y3 = H	1:	Y3/2/1 = H or C				0
		2: Y3/1 = H, Y2 = C	3:	Y3/1 = C, Y2 = H
		4: Y1 = 2Pos D, Y2 = C, Y3 = H	5:	Y3/1 = 15H, Y2 = C
C.12	T2ext	0 = T2 installed	1 = T1 signal used for T2					0
C.13	LimTyp	0 = Low limit	1 = High limit					0
C.14	Senstyp	0 = Auto detection	1 = NTC sensor type					0
C.15	Y1CTRF	Output Y1 used for:	0 = mixed air damper					0
			1= energy recovery
C.16	AddHour	Adjusts the month for winter/summer time change: 0 (disabled) = Min. 12 = Max.						3	month
C.17	SubHour	Adjusts the month for summer/winter time change: 0 (disabled) = Min. 12 = Max.						10	month

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R7426B,C TEMPERATURE CONTROLLER

Config. Parameter			Values				Default	Unit
No.	Name
C.18	PSTG_H3)	Prestart gradient for heating:	0	(disabled) = Min.	2	= Max.	0	K/min
C.19	PSTG_C3)	Prestart gradient for cooling:	0	(disabled) = Min.	2	= Max	0	K/min
C.20	tvd	Use damper before comfort time:	0	(normal control) = Min. 90 = Max.			15	min
C.21	Adapt	Optimum Start Self Adaption speed:	0	= Min.	100 = Max.		50	%
C.22	Adr2)	Serial communication address:	0	= Min.	255 = Max.		254
C.23	DefProg	0 = No Default programming	1	= Initiates Default programming			0

1) for tr > 2 min resolution = 0.5 min, for tr < 2 min resolution = 10 sec

2)actual value will not be changed during reset to default parameter

3)can be overwritten by controller for self-adaption purposes, resolution = 0.01 K/min

FUNCTIONS

Real-Time Clock

The time clock performs automatic change of the controller mode to OFF, Night, Standby, or Comfort in accordance with the programmed time schedule. In Standby or Night mode, the SOFFS or NOFFS is added (cooling) to and subtracted (heating) from the calculated control point. Schedules for one week and up to six switching points per day can be programmed in advance and repeated week after week. In addition, three different holiday schedule types H1, H2 and H3 can be programmed. One of these holiday types can be assigned to each holiday date of the year (01.01. ... 31.12.). Holiday type H1 and H2 is valid only for this specific day and is reset to normal time schedule at midnight of that day. H3 is valid for every year and repeated year after year for fixed holiday dates. H1 can be programmed to be in OFF mode the whole day and H2 to be ON for a short period of time on the last day of a longer holiday period to preheat or precool the space in advance before the first occupied day.

Optimum Start Program

The optimum start program’s objective is to minimize total energy consumption by calculating in room control applications the start time for heating and cooling mode which will bring its respective space temperature to the boundary of the comfort zone at the time of occupancy start. The program will start the ventilation system at the calculated start time with forced return air recirculation mixed air damper position or full energy recovery valve position to minimize energy consumption during the start-up period. At a programmable time before occupancy start, the controller will switch the output signal Y1 to normal and will supply fresh air to the space in mixed air applications. The optimum start program uses historical data for self-adaptive adjustment.

Night Cycle Program

The night cycle program offers not only energy conservation, but also the ability to assign OFF mode night low or high limits with 1 K hysteresis for the protection of a space and its contents against temperature extremes. It automatically cycles between the user selected upper and lower limits and turns on full heating or cooling whenever the limits are reached.

APPLICATION

The R7426B,C controllers can be used for sequence control applications of heating, mixed air damper or energy recovery system, and cooling.

NOTE: All diagrams show proportional control action, only. If P+I control is in operation, the slopes for heating and cooling are not defined.

Temperature Sequence Control with Heating, Mixed Air Dampers, and Cooling

This application will be active with the R7426B,C controllers when T2 is not connected. It can be used for sequence control of a heating valve, a mixed air damper, and a cooling valve.

The characteristic of each output on the R7426C controller can be selected via the control parameters DIR/REVx

(x = Y1, Y2, or Y3). The diagram shows Dir characteristic for all outputs.

Within the range Xp1, the damper signal is controlled as shown in the diagram below. If no cooling actuator is available, the control parameter Xpc can be set to OFF and the damper output is maintained at 100% above control point (CTRP1).

If the damper output should be decreased to MINPOS level above control point (CTRP1) as shown in the diagram, the control parameter Xpc has to be adjusted to any value between 1 and 40 K, also if no cooling actuator is available.

Y[%]
100		1/4 Xp1		if Xpc = Off
	Damper
	Y1
	Y3			Y2
MINPOS	Heating			Cooling
				if Xpc = Off
0
				Xwh / Xwc /Xwd
	CTRPH	CTRP1	CTRPC
	Xph	Xp1		Xpc	T2

NOTE: If the R7426B controller with floating output is used for mixed air damper control, you must ensure that the output load of maximum 450 mA is not exceeded.

EN0B-0301GE51 R0104

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