Honeywell AQS51, AQS61 User Manual

GENERAL

The AQS51 and AQS61 sensor/controllers for room wall mounting measure the carbon dioxide (CO2) concentration and the temperature. They are used in ventilation and air conditioning systems to control the supply of fresh outside air to the occupants for acceptable indoor air quality and to reduce the unnecessary conditioning of outside air during low-occupancy periods.

This Demand Controlled Ventilation (DCV) is a cost-effective solution to conserve energy and to ensure that no more fresh outside air is supplied than is necessary to meet the actual requirements of the occupants at any given time.

The sensor/controllers offer separate 0(2)...10 Vdc or 0(4)...20 mA outputs for CO2 and temperature. In addition, a digital ON/OFF relay output with switching hysteresis and an output selectable as analog or open collector ON/OFF output are available. Both can be used for alarm or other purposes.

The UART interface (RS232) for serial communication allows a PC to be connected to perform maintenance checks or reconfigurations during normal operation.

If used as a controller, each of these outputs can be configured to provide a more complex ventilation strategy based on a mixture of CO2 plus temperature measurements and to assign a number of functions, including hierarchy.

For this analog output configuration, the software program STRATEGY is available, which is part of the User Interface Program Software package AQS-USP22 used for recalibration, changing the measurement range, or other service and set-up purposes.

AQS51/61

COMBINED CO2-/TEMPERATURE ROOM SENSOR/CONTROLLER

SPECIFICATION DATA

The switching setpoint and differential of the relay output for CO2 limit monitoring or plant/system ON/OFF control can be adjusted within the measurement range. This output or the open collector output (OUT4) can be used also as automatic fire threshold to switch off ventilation when the CO2 level exceeds normal limit of e. g. 2000 ppm in case of fire.

FEATURES

•CO2 measurement range 0...3000 ppm according to 0...0.3% CO2. Factory-calibrated 0...2000 ppm

•Multifunctional unit for temperatureand CO2- measurement or control

•State-of-the-art Non-Dispersion-Infrared (NDIR) technology to measure carbon dioxide gas

•Automatic drift correction (ABC-algorithm) based on a long term evaluation provides typical zero-drift check maintenance-intervals of up to 5 years

•Standard 0(2)...10 Vdc or 0(4)...20 mA output signals

for both CO2 and temperature measurement or control

•Programmable mixed controller signal output(s) provides ventilation control strategies to exactly match application requirements

•Digital ON/OFF relay output for CO2 limit monitoring

•Digital input with programmable delay time for external override function e. g. occupancy sensor, push button or switch

•RS232 interface for configuration, parameter setting or data transfer with a PC using Windows 95/98

•User interface program on diskette for service, recalibration, and changing measurement ranges

•Optional with 4-digit LCD display for selectable indication of:

-CO2 concentration / room temperature alternating

-Error code

-CO2 concentration (ppm)

-Temperature (°C)

-Analog Output 1

-Analog Output 2

-Analog Output 4

® U.S. Registered Trademark						EN0B-0374GE51 R0102
Copyright © 2002 Honeywell Inc. • All rights reserved

AQS51/61 COMBINED CO2-/TEMPERATURE ROOM SENSOR/CONTROLLER

MODELS

		Type	Order Number
	CO2	and Temperature Room	AQS51
	Sensor without LCD display
	CO2	and Temperature Room	AQS61
	Sensor with 4-digit LCD display

TECHNICAL DATA

ACCESSORIES

	Description	Order Number
	Service Software; 3.5” Diskette (for
	changing the sensing range, para-	AQS-USP22
	meterization, and post calibration)
	Test set (consisting of a portable gas
	generator for zero-point calibration,	AQS-F0005
	pump, packing, 3m tube, battery, and
	transformer)
	RS Cable with built-in electronics and	AQS3/4 cable or
	adapters	AQS31/41 cable

		Power supply	24 Vac ± 20%; 50/60 Hz or 24 Vdc ± 20%
		Power consumption	2 W
		Sensor life expectancy	>15 years
		Maintenance interval	5 years
	General	Self diagnostics	Complete power/sensor/analog outputs internal test
		Status LED indication	Yellow = Maintenance required; Red = Relay activated
		Power-up time	≤ 60 s
		Ambient operating limits
		- Temperature	0...50 °C
		- Humidity	0...95% rh, non-condensing
		Operating principle	Non-dispersive infrared (NDIR)
		Gas sampling mode	Diffusion and 4 mm gas inlet on bottom of the wall plate
		Response time	120 s (diffusion) or 10 s (0.2 ltr/min gas flow)
		Measurement range	0...3000 ppm
	CO2 Measurement	Converting range	0...2000 ppm = 0...10 Vdc (factory setting)
			or 2...10 Vdc / 0...20 mA / 4...20 mA
		Accuracy	±1% of measurement range, ±5% of reading
		Pressure dependence	+1.58% of reading per kPa deviation from the normal
			pressure of 100 kPa
		Annual zero drift	<±1% of measurement range
		Operating principle	Thermistor
	Temperature	Measurement range	−10...60°C
			0...50 °C = 0...10 Vdc (factory setting)
	Measurement	Converting range
			or 2...10 Vdc / 0...20 mA / 4...20 mA
		Accuracy	±0.2 K
		Settings and configuration with
		Service Software AQS-USP22
	P control	- Throttling range CO2	100...800 ppm
		- Throttling range temperature	1...10 K
		- Reset time adjustment range	2...500 s (factory setting: 300 s)

EN0B-0374GE51 R0102

2

AQS51/61 COMBINED CO2-/TEMPERATURE ROOM SENSOR/CONTROLLER

		For connection of potential-free	Open > 40 kΩ
	Digital input 1	contact	Closed < 100 Ω
		Power supply 5 Vdc
		Closed contact current 1 mA
		Output signal	0...10 Vdc / 2...10 Vdc, impedance <100 Ω,
			load >5 kΩ or 0...20 mA / 4...20 mA, load ≤500 Ω
		Resolution	10 mV (10 Bits)
	Analog outputs	D/A conversion accuracy	±2% of output voltage, +0.1 V
			±2% of output current, ±0.3 mA
		Protection	PTC fuse (auto reset), short-circuit proof
		Customization of P controller	Both outputs can be configured to any sensor mix (CO2 +
			temperature + digital input of 5 proportional ranges with
			priorities and offsets, using STRATEGY, Version 4.0)
		Single pole, Normally Open (NO),	1 A / 50 Vac (50 VA) or 1 A / 24 Vdc (30 W)
	Digital relay output	potential-free contact.
		Factory-adjusted switching setpoint	Relay activated: ≥1000 ppm
		and differential	Relay deactivated: ≤900 ppm
	Analog output or digital	Analog output signal	0...10 Vdc, impedance <100 Ω, load >5 kΩ
	open collector output	Digital open collector output	Max. 0.5 A, 60 Vdc or 40 Vac (half-wave rectifier protection)
	Dimensions	Housing (L x W x D)	(120 x 82 x 30) mm
			By pressing the push button, one of the following display
			modes on the 4-digit display is selectable:
			- CO2 and temperature, alternating
			- Error code
	Push-button	MENU	- CO2 in ppm
			- Temperature in °C
			- Analog output 1
			- Analog output 2
			- Analog output 4

DIMENSIONS

Fig. 1. Dimensions (in mm)

3	EN0B-0374GE51 R0102