industrial multi-burner furnaces to detect and discriminate the operating burner flame. UVISOR MFD behaves as a true “Two-Systems-in-One”, processing simultaneously the flame signals carried by two scanner heads regardless the sensor spectral range (Ultraviolet or Infrared) or the electrical signal type (amplitude/frequency modulated signal or pulse rate signal).
It can achieve a stable flame-on status and a reliable discrimination at various load rates thanks to a proven algorithm, which analyses the flame’s flicker spectrum and tunes consequently the basic parameters of the amplifier. The UVISOR MFD provides the “Individual channel maintenance power-off” utility thus to offer a cost effective application options where simultaneous and independent control for burner and pilot flame or two burners flame scanners are required.
UVISOR MFD process simultaneously flame signals from two scanners on two separate channels. Each channel can be configured to use two different techniques to detect the flame. Based on the detector types, these techniques are:
• Flicker frequency receiver • Pulse counter receiver
associated flame relay, they can also be connected in logical OR/AND to generate one unique flame status.
Whether the two channels are logical interconnected (AND & OR) the second channel relay is available to output a secondary flame on status.
Each channel can be independently tuned. Four set up files per channel can be selected from remote (BMS) to get the best tuning at the various burner/boiler operating condition. Tuning parameters are secured on non-volatile memory.
Acquisition, processing, display and control functions of the UVISOR MFD are microprocessor based.
Safety and reliability of the flame control process is assured by the hardware and firmware Fail-Safe characteristics and by the diagnostic tasks constantly operating.
UVISOR MFD provides enhanced feature to ease the tune-up, to supervise the flame quality, to speed-up diagnosis:
− Separate analogue output. One for each flame detector. − Automatic parameter setting.
− Connection to a local Monitoring Station through RS232 which features: − Real time flame signal trends and archive on scroll diagram.
− View, upload and download parameters from/to the unit. − Download new firmware releases.
− Flame flickers spectrum analysis (with burner on/off and difference plot out).
− Connection to a remote SCADA through RS485 network based on MODBUS standard.
− Separate raw signal from the scanner heads suitable for PC standard Sound- Board. Unconditioned flame signal is rendered for further flame performance analysis.
− One thermocouple input and related alarm output to measure and prevent the hot side of the scanner from overheat.
Technical specifications
1Power supply
Power Supply Voltage - 120+220Vac +/- 20% 45+65Hz - 30VA (6A/5ms in-rush current) - 24Vdc +/- 20%
- 22W
Fuse rating - AC Power supply 2AT 250V - DC Power supply 4AT - Relay outputs 6A
2 Outputs
Contacts rating Channel 1, 2 Flame relay and watch dog - 1 SPDT standards VDE0110
- 250 Vac 3A cosf ≥ 0.4 750W cycles ≥ 250 Vdc 300 mA 66W
Temperature alarm
- 1 SPST standards VDE0110
- 100 Vac 0.3A cosf ≥ 0.4 30W cycles ≥1E5 Scanner Power Supply - 24Vdc refereed to common for bias and blind
Bias Contact Power Supply - 24Vdc refereed to common for contact bias - Short circuit and overload protected
Nr. 2 Analogue outputs - Configurable as follow: 0÷10V (R out = 600 Ω ) 4÷200mA ( R load < 500 Ω) Flame signal reading +/- 30 dB Galvanically isolated
Protected against short circuit
Flame raw signals Two (2) 0 dBV output level. 3 Inputs
Channel Set up Selection - Nr. 2 inputs opto coupled for each channel allow to select four different set
Off: < 5 Vdc
On: < 16 Vdc (4.5 mA typical). Vin max. 24Vdc Thermocouple - Nr. 1 Thermocouple input type “J”
4 Mechanical Specification
Dimensions - Europe Single Standard
- Height: 3 Units, 5.06” (128.4 mm) - Width: 21 TE, 4.19” (106.3 mm) - Depth: 6.3” (160mm)
- Protection CEI EN 60529: IP20 Weight - 1.2 Kg
Installation - 19” Rack mounting (See section…)
Legend
1 LED CH-1 When on it indicates the CH.1 flame relay energized 2 LED CH-2 When on it indicates the CH.2 flame relay energized 3 DISPLAY Alphanumeric 2*16 characters LCD. Graphic
4 MENU KEYPAD Allow to brows the MFD option and program the operating parameters
5 DB9
CONNECTOR “COM”
RS232 isolated serial output
When “NET” LED (8) is on the RS232 is accessing the network
6 SET UP MODE TOGGLE
Enabled/disabled set up function. When LED is flickering set-up is enabled
7 SAFE LED When on it indicates the MFD has no failure and the relevant Watch Dog relay is energized
2 UVISOR FLAME SCANNERS UR600
Scanner UR 600 is in explosion proof construction, CESI certificate No. AD 83.062 ext. 02/89 EExd, according to CENELEC Standards EN 50.014-1977 (CEI 31/8/78) and EN 50.018-1977 (CEI 31/1/78), FM and CSA. The case has an IP66 (NEMA 4X) degree of protection in accordance with IEC standards 144-1963.
The Scanner UR 600 IR houses a glass lens, a PbS photoresistor sensing element and a signal conditioning / pre-amplification PCB. Terminals to the control unit are screw type.
The Scanner UR 600 is also available in special versions with rigid or flexible probe capable to collect signals in the nearest of the flame inside the combustion chamber, and suitable for installation in corner-fired application.
• SCANNER UR 600
In both the direct view and extended version, the flame detection and discrimination is bases on the capability of the scanner UR 600 Model IR to sense the IR wavelength.
The PbS photo resistor sensitive element reacts to the dynamic characteristics of the intensity of IR radiations issued mainly by the flame in the zone where primary combustion takes place (flame root).
The pre-amplification circuit, hosed in the scanner head, conditions the electrical signal to be transferred to a remote location where the control unit MFD.SA is installed.
• SELF-CHECKING
The MFD.SA control unit cyclically executes a self-checking task. In case an error is detected the watchdog is reset and a message appears. The IR PbS photo resistor is an intrinsically fail-safe device; it reacts to the flame presence only, providing an AC signal (flickering) to the MFD.SA, which energizes the flame relay.
The MFD.SA performs the self-check removing the bias voltage from the sensor element. No electromechanical shutter is involved.
The following checks are made: - Self-checking loop integrity. - Ripple detection.
During self-check an error message IRSC is generated if the flame signal does not go to zero within a selected time, while the error message IRBL is generated in case of short circuit on the self-checking loop.
During self-check an error message IRSC is generated if the flame signal does not go to zero within a selected time, while the error message IRBL is generated in case of short circuit on the self-checking loop.
Self-check continues testing the programmable cut-off filters.
Four combinations of pass-band are set and for each one of them the filter behaviour is checked.
In case of fault a specific error message appears and the Flame signal is forced OFF. Also in this case, the control is repeated cyclically and the normal situation is restored in case of Flame detected and successful tests.