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Model GIR901

Infrared Combustible Gas

NOVA-Sensor

D

ESIGN

 M

ANUAL

T h e   i n f o r m a t i o n   a n d   t e c h n i c a l   d a t a
d i s c l o s e d   b y   t h i s   d o c u m e n t   m a y   b e
u s e d   a n d   d i s s e m i n a t e d   o n l y   f o r   t h e
p u r p o s e s   a n d   t o   t h e   e x t e n t
s p e c i f i c a l l y   a u t h o r i z e d   b y   S

A F E T Y

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Y S T E M S

  T

E C H N O L O G Y

  i n   w r i t i n g .   S u c h

i n f o r m a t i o n   a n d   t e c h n i c a l   d a t a   a r e
p r o p r i e t a r y   t o   S

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d i s s e m i n a t e d   e x c e p t   a s   p r o v i d e d   i n   t h e
f o r e g o i n g   s e n t e n c e .

7 0 0 4 3

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A F E T Y

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Y S T E M S

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E C H N O L O G Y

2 3 2 8 2   M i l l   C r e e k   D r i v e ,   S u i t e   2 1 5
L a g u n a   H i l l s ,   C a l i f o r n i a   9 2 6 5 3   U S A
T e l   1 - 9 4 9 - 5 8 3 - 1 8 5 7       F a x   1 - 9 4 9 - 3 4 0 - 6 6 4 3
w w w . s a f e t y s y s . c o m

The information in this document is applicable to

sensors built on or after October, 2001

Summary of Contents for NOVA-Sensor GIR901

Page 1: ...n f o r m a t i o n a n d t e c h n i c a l d a t a a r e p r o p r i e t a r y t o S A F E T Y S Y S T E M S T E C H N O L O G Y a n d m a y n o t b e u s e d o r d i s s e m i n a t e d e x c e p t a s p r o v i d e d i n t h e f o r e g o i n g s e n t e n c e 7 0 0 4 3 S A F E T Y S Y S T E M S T E C H N O L O G Y 2 3 2 8 2 M i l l C r e e k D r i v e S u i t e 2 1 5 L a g u n a H i l l s C a ...

Page 2: ......

Page 3: ...IP Switch settings 901 8 OPERATION 901 9 Power Up 901 9 Changing the Setpoints 901 9 Calibration 901 10 Recalibration Schedule 901 12 NOVA SENSOR OUTPUTS 901 12 0 to 20 mA Current Loop 901 12 Relay Outputs 901 12 FINAL OPERATIONAL CHECK OUT CompTest 901 13 How to Start the CompTest 901 13 Entering the Safety Code 901 14 CompTest Operational Sequence 901 14 MAINTENANCE 901 15 Replacing the Infrared...

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Page 5: ... increase remove the gas now The sensor will reset its calibration to read 50 and hold this reading for about 3 minutes Normal operation begins once the displayed level is safely below the LOW alarm setpoint Alarm Setpoints To check the alarm setpoints without declassifying the area simply press the large external MODE button for 1 second Each alarm setting will be displayed for 5 seconds along wi...

Page 6: ...nals With a constant length of the optical axis the relation between the active refer ence ratio and the actual gas concentration is logarithmic The length of the optical path yields an output for hydrocarbons that allows measurements with a resolution of 1 2 of reading The ratiometric principle makes it possible to eliminate almost all effects of temperature aging or fogging that would otherwise ...

Page 7: ...Detectable gases with sensitivity relative to Methane Methanol 10 Propane 9 3 Butane 8 6 Ethane 8 0 Diesel 7 5 Ethanol 7 1 Hexane 5 8 Octane 5 7 Iso propanol 3 4 Pentane 2 5 Methane 1 0 Acetone 0 7 Toluene 0 5 Ethene 0 3 For all gases with absorption lower than Methane special versions of the GIR901 have to be used The detector should always be calibrated with 50 LEL Methane TABLE 2 Other gases th...

Page 8: ...a load of 600 ohms or less INSTALLATION A complete GIR901 unit consists of an explosion proof housing with MODE button Infrared gas sensor head terminal blocks for field wiring and transparent lid used to observe the operational status of the numerical readout and LED s The field wiring is connected to the terminal blocks inside the enclosure The terminal blocks are accessible after removing the e...

Page 9: ...ure The dimensions of the GIR901 are shown in the figure below It is preferable to attach the sensor to a wall or bracket using bolts through the two mounting holes However these mountings may be omitted if the electrical conduit is sufficiently rigid to support the weight of the detector The location of the sensor is important For lighter than air gasses such as methane the sensor should be locat...

Page 10: ...button on the NOVA Sensor housing can be used to clear any relays or alarms in the NOVA Sensor which have been latched when activated Pressing the button for less than 3 seconds 0 5 second minimum will cause the latched relays to clear and the alarm setpoints to be momentarily displayed An optional external remotely located pushbutton can be wired to the terminal marked RESET This should be a norm...

Page 11: ...ients See figure 901 5 and the section Relay Protection Circuitry below Remote Sensor Version The remote sensor version is the same as a standard version except that the sensor head is located away from the electronics enclosure A SST Model GIR900 Infrared Combustible Gas Sensor is required for use with the remote GIR901 electronics package A second 3 4 inch conduit connection is provided to conne...

Page 12: ...Switches 1 2 and 3 are preset at the factory to DOWN UP UP for switch positions 1 2 and 3 respectively DO NOT ADJUST these switches Serious damage to the sensor or electronics module may occur if these switches are incorrectly set Switch position 4 selects the LOW alarm relay as latching or non latching The UP position selects LATCHING mode once activated the low alarm relay will remain in the ala...

Page 13: ...perating at the factory default calibra tion and alarm setpoints Calibration data and alarm setpoints are maintained in non volatile memory to insure proper operation should the 24 VDC supply be temporarily interrupted No special care is required to maintain this memory Changing the Setpoints Setpoints for HIGH alarm and LOW alarm are available for user modification Factory defaults for the HIGH a...

Page 14: ...imit LEL of the gas The GIR901 must warm up for at least 7 minutes after power is first applied before calibrating Calibration will be more accurate if you can wait 30 minutes before starting Do not push the MODE button on the housing during the first 10 seconds of warm up or previous calibration data will be erased from the non volatile memory The calibration procedure is as follows 1 Depress the...

Page 15: ...nsor automatically stores the calibration in its internal non volatile memory for use in subsequent measurements During the calibration process the 4 20 mA output is set to 2 mA and the relay outputs are suppressed The NOVA Sensor automatically returns to normal operation when the calibration is complete Failed or Incomplete Calibrations If the calibration procedure is aborted e g by not applying ...

Page 16: ...in the sensor or the current loop wiring the output will of course be 0 mA Before any calibration has been performed the output will be 2 mA During the start up time delay and during routine calibrations the output remains at 4 mA During normal operation the loop current can be determined with the following formula I in mA 4 0 16 x LEL Relay Outputs The NOVA Sensor includes three 3 relays for conn...

Page 17: ... safe guards against its inadvertent use The button located on the side of the NOVA Sensor the Mode button will not initiate a CompTest The remote reset input on the NOVA Sensor is used to initiate the test based on a coded sequence of ON s and OFF s Upon receiving the proper coded input the CompTest Safety Code the NOVA Sensor begins the test The NOVA Sensor will only start the output tests if th...

Page 18: ...een cycled Wait for 5 seconds after releasing Reset then enter the Safety Code as described in the following section Entering the Safety Code After following the previous instructions to insure that the NOVA Sensor is ready to accept the Safety Code press the Reset Button for three 3 ON cycles 5 to 10 seconds each separated by 5 to 10 second pauses This will cause the sensor to execute the CompTes...

Page 19: ...tive and inactive Upon completion of the CompTest the built in test BIT is executed and the system then returns to normal operation If desired the output test can be repeated by again entering the CompTest security code MAINTENANCE The GIR901 is easy to service Most service activities will require the lid of the detector base or the enclosure of the GIR900 sensor head to be opened CAUTION Before o...

Page 20: ...s manual Digital Readout Module Replacement If the electronics module with digital readout ever has to be replaced the new module must be calibrated to the sensor head installed on the enclosure Spare Parts Installations which require on site spare parts inventory should order the following part numbers 40901 02 Combustible Electronics Module with digital readout 40901 35 2 Plug in Transmitter Mod...

Page 21: ...he enclosure in the same way 2 Unplug the two suitcase jumpers located on the headers labeled TOX on the lowermost printed circuit board of the electronics module stack note jumper position for later re insertion Clean contacts inside of jumper and on pin header If possible insert a new clean suitcase jumper with gold plated contacts Alternatively the two header contacts at TOX may be connected by...

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