The ZX-212 inflammable gas detection and alarm controller belongs to the variety of smart alarm controllers and can be used with the SC610 inflammable gas detector. Normally, the controller is installed in a safe place where observation and maintenance is easy to realize. Signals obtained by the detector are transmitted to the controller in the 485 bus mode. The controller can display the current channel No., channel concentration, the alarm or failure status. When the concentration exceeds the preset alarm value, the controller can give an acousto-optic alarm and send control signals to prompt operators, thus helping to avoid accidents.
The ZX-212 inflammable gas detection and alarm controller can be extensively useful on many leakage-easy-to-happen occasions, indoors or outdoors, such as production, storage and usage of inflammable gases in the industry of chemicals, petroleum, metallurgy, oil tank farms, liquefied gas stations, spray-painting works, and gas transmission and distribution.
The design and manufacture of the ZX-212 inflammable gas alarm controller is in compliance with GB16808-1997, Technical Requirements and Test Methods for Combustible Gas Alarm Control Units, and relevant China national standards and regulations.
Ø The controller is easy to operate. Its interface is simple and friendly, offering most convenient operation to users.
Ø Providing abundant amounts of information to help operators to hold a full knowledge of the controller’s operation states.
Ø Capable of recording latest alarm messages, making accident tracking possible.
Ø The controller cabinet is small and can be mounted on wall simply and easily.
Ø Gas concentration is displayed by liquid crystal digits, clearly and visually.
Ø With only four buttons necessary to complete all operations, the button mode simplifies the operation.
Ø The power of the controller can be switched over between the main and the standby to make sure the controller can work well in case of an accident.
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Type
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ZX-212
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Voltage Range
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AC 220V±20%
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Channel Capacity
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16
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Wiring Type
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485 bus system
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Temperature
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-10℃～55℃
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Relative humidity
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93%RH
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Sound pressure range
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>75dB/m
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Working time of the standby power
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>2 hours
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Alarm concentration
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Primary alarm default: 25%LEL（adjustable）；secondary alarm：50%LEL
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Stability
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If works for a long period, the controller has an alarm concentration error not more than ±3%LEL
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Alarm concentration error
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Not more than ±3%LEL
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Alarm type
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Acousto-optic alarming, with LEL concentration displayed in a liquid crystal display
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Structural Dimension
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350mmX280mmX93mm
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Weight
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Executive Standards
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GB16808-1997
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As for the controller, LCD is used to display and the R485 mode is used to communicate. The controller receives correspondent information and transmits it to CPU for analysis and processing, and then gives corresponding display, acousto-optic signals and output signals.
Tasks of the Controller:
■ Firstly, providing the power supply for detectors and charging standby batteries.
■ Secondly, analyzing the received data and giving the corresponding display, acousto-optic signals and output signals.
■ Thirdly, recording alarm time, alarm concentration and No. of the alarming detector, and offering the inquiry function.
n Installation
The controller is not in an explosion-proof structure so that it should be installed in a safe place. Its installation position shall make the controller easy to observe and maintain. There shall not be a strong electromagnetic field (such as motors, transformers and power cables) around the controller; otherwise the controller would be impacted.
n Functions
The ZX-212 controller is easy and simple to operate as only four buttons, three indicators and one LCD are arranged, to the utmost extent providing convenience for users. Moreover, the interface is very simple and friendly.
Fig. 1
Buttons
Ø “Set”key：for setting parameters.
Ø “∧Function”key：upward key, for increasing the set value.
Ø “∨Silence”key：downward key, for decreasing the set value; also for eliminating an alarm sound.
Ø “ENTER”key：for confirming an input.
Indicator
Ø Standby power indicator（green）：displaying that the controller is powered by the standby power
Ø Failure indicator （yellow）：displaying failure information including whether the sensor is ok, whether the connection between the detector and the controller is ok, and whether the charging circuit is ok.
Ø Alarm indicator（red）：displaying whether the gas concentration is out of the limit.
Screen
Data and time are displayed in the upper part; and detector channel No., gas concentration of the channel and detector status are displayed from left to right in the lower part. For example,
Detector Status
Gas Concentration
Channel No.
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Fig. 2
Meanings of items in the Detector Status:
PREHE. ：The detector is preheating;
NORMAL：The detector works well;
OPEN！：The detector is open-circuited;
SHORT！：The detector is short-circuited;
COMBAD：The detector has communication failures.
The last three situations as mentioned above belong to the case of failure occurrence. In such a case, the failure indicator (yellow) twinkles slowly and the speaker rings. The “V” key shall be pressed to stop the sound. The screen displays which channel is at fault and what failure happens. After the failure is removed, the alarm shall be automatically eliminated.
When the controller is powered up, sensors shall be preheated for 4 to 5 minutes with the screen displaying “Preheating ... Wait 5 Minutes”. After the sensors are preheated, the controller enters a normal monitoring status with the screen displaying what the diagram 2 shows.
A password menu is arranged at the ZX-212 controller. Press the “Set” key for inputting the password to perform various functions. If a mistake is made in password entry, “Password Error” will be prompted. Press the “Set” key to cancel this operation and press “Enter” key to make a new entry.
Password Setup——Press the “Set” key to display:
When the "Set” key is pressed every time, the cursor moves to the next position among all set positions. Press the (∧) key to set “1” and press the (∨) key to set “0”.
Operations for the Functions
u Set an effective channel—— Password is “000000”, and press “Enter” to confirm the entry and the screen displays:
The first row shows channel No.; the second row shows whether the channel under the No. is in linkage. “1” represents the detector under the No. has been linked while “0” represents no linkage.
When the "Set” key is pressed every time, the cursor moves to the next position among all set positions. Press the (∧) key to set “1” and press the (∨) key to set “0”. Press the “Enter” to save and quit.
◆Set date, time and alarm points ——Password is“100000”， and press “Enter” to confirm the entry and the screen displays:
Press “∧” and “∨” to adjust alarm parameters or change date and time. When the "Set” key is pressed every time, the cursor moves to the next position among all set positions. Press the “Enter” key to save and quit.
Continue to press the “Set” key to move the cursor, one position by one pressing, in a cyclic manner. Common items are available at first. Press the “Enter” to save and quit.
u Alarm record inquiry——Password is “200000”，and press the “Enter” key to confirm the entry and the screen displays:
Recorded items
Alarm concentration set value
Concentration value at alarm
Channel NO.
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Press “∧” and “∨”to observe alarm records. A total of 16 messages can be recorded. Press the “Enter” key to save and quit.
Concentration value “E！” means that the concentration at alarm is higher than 100%LEL.
u Acousto-optic system detection——Password is “300000”， and press the “Enter” to confirm the entry. The screen is blank. At that time press the “Function” key to let all LEDs light and the alarm ring. Press “Enter” to quit.
u Manual polling——Password is “400000”, and press the “Enter” to enter the manual polling state. The channels are displayed in a single-step mode. Press the “∨” key every time to go to the next channel. Press the “Enter” key to quit the manual polling state.
If the detector finds gas concentration is out of the limit, the controller shall initiate the acousto-optic alarm and trigger the relay (users can start exhaust fans or close gas solenoid valves through linked relays); and the LCD displays only alarm channels, for example:
Total number of alarm channels
First alarm channel No.
Concentration at alarm
Alarm channel No.
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When the displayed concentration is more than the set value (25%LEL set by factory), the alarm indicator starts to twinkle and the speaker begins to ring (similar to the 120 alarming sound). When the displayed concentration is more than 50%LEL, the alarm indicator becomes quick-flashing and the speaker makes another sound (similar to the 110 alarming sound). During alarming, by pressing the “∨” key, the sound can be shut up and only information on the alarmed detector is displayed on the screen. When the gas concentration is reduced below the set value, the controller will automatically eliminate the alarm.
The alarm equipment is equipped with a standby power (a storage battery) to guarantee normal operation in case of a power interruption or an electric supply failure. When the standby power is working, the standby power indicator is light, the failure indicator flashes quickly and the speaker rings slowly. Press the “∨” key to shut up the sound. For a polling of 1 to 2 weeks, the LCD displays “POWER DOWN OR CONTA. IS BAD!” until the main power supply is on duty. The working time of the storage battery is not less than 2 hours.
Similarly, the polling continues even if the standby power is at fault. But in the event, the standby indicator is not light, the failure indicator flashes quickly and the speaker rings slowly. For a polling of 1 to 2 weeks, the LCD displays “POWER DOWN OR CONTA. IS BAD!” until the standby power supply becomes normal.
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Fault Type
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Fault Reasons
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Solution
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No display on the screen after powered up
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Access to electric supply is wrong;
The switch power is broken
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Check the electric supply circuit
Change the switch power
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Failure alarm
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Open-circuit or short-circuit of the connection of the detector and the controller
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1 Check if the terminal of the controller is firmly connected with the transmission line
2. Check if the terminal of the detector is firmly connected with the transmission line
3. Check if the terminal in the detector is firmly connected with the sensor line
4. Check if the transmission line is broken or if the short circuit occurs between lines.
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When making a calibration by using standard gases, the gain potentiometer fails to reach the set value
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Degradation of performance of the sensor
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Replace the sensor
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The display and the alarm light are normal, but there is not an alarm sound
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Check if the “Silence” key is pressed
The speaker is broken
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Replace the speaker
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Connection and Debugging
A) Port Connection
●Connect Port A of the 485 bus with the wiring access RA of the controller
●Connect Port B of the 485 bus with the wiring access RB of the controller
●Connect the VCC (or R+) of the detector with the wiring access R+ of the controller
●Connect the GND (or R-) of the detector with the wiring access R- of the controller
●The output ports, K1, K2, K3 and K4, have two interfaces respectively, i.e. four groups of relay outputs.
★Wherein, RA, RB, R+ and R- have two groups with the same functions and connection.
B) Debugging
Generally, the setup of a controller has been made before leaving factory. The controller is useful directly after connection. If users encounter the following matters, further setup shall be needed:
1．Regulate smaller alarm points
The primary alarm point is 25%LEL at default before leaving factory. If a smaller alarm point is needed, the user can enter the <Date, Time and Alarm Point Setup> interface to regulate the alarm value in accordance with the instructions. It is recommended that the primary alarm point should be in the range of 5%-%25LEL and the secondary alarm point should not be regulated at default of 50%LEL as specified by relevant national standards.
2．When detectors with different address codes are added, reduced or changed, the setup shall be made.
According to the operation instruction, enter the <Effective Channel Number Setup> interface, set and acknowledge the address code of the detector in use as “1” and the unused channels as “0” .
Ø When a concentration alarm for the controlling system takes place, DO NOT switch on switches of electrical equipment. You should determine the reason for gas leakage and make a prompt treatment. If the reason is not clear, please contact a related gas department for a thorough inspection.
Ø When the controller failure indicator is light, the power supply shall be switched off and the power and the signal line of the sensor shall be checked if short-circuit or open-circuit occurs. If the connection is ok, the sensor may be ineffective and should be replaced.
Ø Considering that the explosion-proof type of the detector is explosion isolation, the case cover must be tightened after the cables are connected. Only after the power is off on site can the cover be opened.
Ø Highly concentrated aerosol, atomizing pesticide and combustible solvent around the detector may cause an alarm.
Ø A new sensor taking the place of a broken or ineffective sensor must be calibrated by using standard gases after replacement is completed.
Ø If any failure occurs to the controller, the user shall send the controller to the manufacturer for repair and calibration, or inform the manufacturer of the failure to let manufacturer’s service personnel maintain and repair the controller.
Ø Careful handling of the instrument is necessary to avoid strong shock or impact during its installation.
Ø If the instrument has to be set aside for a period, it must be stored in a dry and well-ventilated place where no aggressive gas shall be present in air.
Ø The service life of the product is 5 years. The product is offered by life-long maintenance.
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