SenTech IR-SNIF-MC-1 Installation And Operation Manual Download Page 5

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Models MCD-1, 4, 8 & 16 Specifications

Size:

16.5” x 15” x 6.75” (42cm x 38.1cm x 17cm)

Weight:

Model MCD-1     - 30.4 lbs. (13.8 kg)
Model MCD-4     - 31.4 lbs. (14.2 kg)
Model MCD-8     - 33.8 lbs. (15.3 kg)
Model MCD-16   - 36.0 lbs. (16.3 kg)

Power:

120 or 240 Volts AC 50/60hz (41 Watts)

Temperature:

32 deg F – 125 deg F (0 deg C – 50 deg C)

Humidity:

0 – 95 % non-condensing

Atmospheric
Pressure:

75-106 Kpa
Equipment rated for indoor use only

Range:

0 – 1000 ppm Standard

Tube Length:

0 – 250 ft (0 – 76 m)

Sample
Areas:

Model MCD-1     - 1 Area
Model MCD-4     - 4 Areas
Model MCD-8     - 8 Areas
Model MCD-16   - 16 Areas

Trip Point:

Low Alarm    0 – 1000 ppm
Main Alarm   0 – 1000 ppm
High Alarm   0 – 1000 ppm
Horn Alarm Programmable to Low, Main or High

Leak Wait:

Varies from seven (7) seconds to three (3) minutes depending on
refrigerant concentration

Alarm
Output:

Low, Main, High and Horn alarm relays, each with four (4) form C
contacts rated 5 amps maximum

Analog
Output:

0 – 10 volt proportional to 0 – 1000 ppm
4-20 mA (optional)

Computer
Interface:

RS-485 (optional)

Summary of Contents for IR-SNIF-MC-1

Page 1: ...SenTech Corporation 5745 Progress Road Indianapolis Indiana 46241 888 248 1988 FAX 317 248 2014 INSTALLATION AND OPERATION MANUAL ENVIRONMENTAL SYSTEM IR SNIF MCD MODELS MCD 1 4 8 16 ...

Page 2: ...IF MCD press the key This will display momentary screens that provide contact information for SenTech Corporation the software version and any options enabled in the monitor If your monitor has a version that is older smaller version number such as 2143 a version specific appendix A Programming and Operator Interface is available It can be downloaded from the SenTech Corporation website www sentec...

Page 3: ...15 STARTUP and PROGRAMMING 18 Apply Power 18 Initial Screens 18 Normal Operation 19 Initial Programming 19 FINAL TESTS 25 Monitor Sequencing 25 Integration with External Devices 25 Response to Refrigerant 26 End to End System Test 27 Documentation 28 PREVENTIVE MAINTENANCE REPAIR 29 Preventive Maintenance 29 Commonly Ordered Parts 29 Monitor Repair 29 APPENDIX A Programming and Operator Interface ...

Page 4: ...hat the terminal must be connected to earth ground before operation of the equipment Caution This sign calls attention to a procedure or practice which if not adhered to could result in damage or destruction to a part of the product Other information and precautions Input Power Power should be supplied through a two pole circuit breaker located in a reasonable proximity to the equipment Ensure tha...

Page 5: ...or use only Range 0 1000 ppm Standard Tube Length 0 250 ft 0 76 m Sample Areas Model MCD 1 1 Area Model MCD 4 4 Areas Model MCD 8 8 Areas Model MCD 16 16 Areas Trip Point Low Alarm 0 1000 ppm Main Alarm 0 1000 ppm High Alarm 0 1000 ppm Horn Alarm Programmable to Low Main or High Leak Wait Varies from seven 7 seconds to three 3 minutes depending on refrigerant concentration Alarm Output Low Main Hi...

Page 6: ...wer Supply Refer to figure 1 for an overall block diagram The pneumatics pulls sample air or reference air from up to 250 feet and pumps the air through a filter to a pressure sensor through the infrared bench and out the exhaust port of the monitor The infrared bench provides an infrared source and measures the presence of refrigerant based on measured changes in the infrared light The control el...

Page 7: ... Sample air and the Auto zero air valves Following an Auto zero cycle the pneumatics will be switched to the next sample valve in order The diaphragm pump draws air from the selected inlet and feeds the air through a five micron filter through an orifice restrictor through the infrared bench and to the exhaust port located on the lower right side of the unit The pressure switch monitors the pressu...

Page 8: ...h has an integrated source circuit with infrared source at one end and an integrated detector circuit with filter and detector at the other Presence of refrigerant in the sample air will cause a change in the output of the detector IR Bench Control Electronics Figure 3 Infrared Bench ...

Page 9: ... exposure or a leak truly exists If the ppm level remains above the Low alarm threshold on completion of leak wait the Low alarm relay is energized If the signal continues to increase the Main alarm relay will be energized and ultimately the High alarm relay Once the system enters Low Main or High alarm it will remain in that mode until the problem is cleared and the system is reset IR Bench Press...

Page 10: ...ne voltage is fed through the fuse on the left side of the monitor not shown and to the diaphragm pump and power supply The power supply converts AC line voltage to dc voltage DC Voltage is fed through the terminal board to all of the electrical components of the monitor Terminal Board Control Electronics Power Supply Figure 5 Power Supply Diagram ...

Page 11: ...nal then also in the sample The ppm level is based on the ratio of the sample to the reference This ratio eliminates the effect of any variations and eliminates the need to periodically calibrate a monitor in the field PPM vs Leak Rate The relationship between the actual amount of product lost and the resulting ppm level refrigerant in the air is complex There is no direct relationship between the...

Page 12: ...igerants and interfering chemicals 12 18 from ceiling if indoors Purchased separately from monitor or customer supplied Included inside monitor Included inside monitor Power Connection Field Wiring 120 or 240 VAC 50 60 hz 12 or 14 AWG Voltage jumper selected inside monitor Provided by customer Install in accordance with NEC and local codes Valves Area 1 Reference Air Area 5 Area 6 Area 2 Area 4 Ar...

Page 13: ...stall in accordance with NEC and local codes use HIGH alarm relay to switch line voltage for contactor or to switch control voltage for exhaust fan control BMS Control Connections Analog Binary OP 001 OP 001 2nd Field Wiring OP 002 Field Wiring Analog 1 output 0 10 volts provides measurement of current area being monitored Analog 1 output 4 20 mA provides measurement of current area being monitore...

Page 14: ...ct to cable length limitations of rs 485 powered by 24 vac transformer Provided by customer Install in accordance with NEC and local codes Optional Purchased separately from monitor provides complete remote interface from PC to all monitors in building via rs 485 interface subject to cable length limitations of rs 485 used with Windows based software provided with COMM LINK Provided with COMM LINK...

Page 15: ...ion ASHRAE 15 specifies that the refrigerant monitor is to be located in the mechanical room There are two interpretations of this the unit itself is to be installed in the mechanical room or the sample point is to be located in the mechanical room Because the IR SNIF MCD is an active air draw monitor it can be installed nearly anywhere in the vicinity of the area to be monitored If local codes al...

Page 16: ... end filter must be protected from the elements Water ice or insects can partially obstruct the tube end filter and change the reference signal 5 If located outdoors the tube end filters must not be located near exterior HVAC equipment or any potential source of refrigerant Exhaust Location The exhaust tube is required only if the monitor is not located in the same room as the sample pick up point...

Page 17: ... that the unit will inadvertently be unplugged putting it off line Electrical Alarm Connections Relay Connections The IR SNIF MCD monitor alarm relay sockets have four sets of NO NC dry contacts Refer to figure 7 for a diagram of the relay socket Figure 7 The terminals are grouped as follows Terminal 9 Common Terminal 1 NC Terminal 5 NO Terminal 10 Common Terminal 2 NC Terminal 6 NO Terminal 11 Co...

Page 18: ...cess of the relay rated amp capacity A pilot relay or contactor will normally be required to energize an exhaust fan Unless specified otherwise SenTech Corporation recommends the following connections for exhaust fans 1 Fan pilot relay or contactor connected through HIGH RELAY terminals 5 and 6 on TB2 BMS to Relay Connection The IR SNIF MCD monitor alarm relay can provide alarm indications to the ...

Page 19: ...ppropriate wires to TB3 1 analog 1 plus and TB3 3 reference ground 4 Connect the appropriate wires to TB3 2 analog 2 plus and TB3 3 reference ground 4 20 mA Optional Analog Outputs The IR SNIF MCD monitor provides a optional 4 20 mA analog outputs in place of the standard 0 10 volt analog outputs To identify whether a monitor has 4 20 mA analog output installed examine the control board installed ...

Page 20: ... wire harness using tie wraps 3 Connect the transmit conductor to TB3 6 4 Connect the receive conductor to TB3 8 5 If twisted triple wire is used connect the remaining wire to TB3 7 reference or shield ground 6 If two twisted pairs are used connect one conductor from each pair to TB3 7 reference ground or shield Custom Control Inputs Outputs The IR SNIF MCD monitor has the capability to be program...

Page 21: ...lay this screen on initial application of power Following memory initialization the monitor will display the copyright screen The monitor will next display two Contact and Model Information screens Note these screens can be accessed anytime during normal operation by pressing the key Following display of the contact and model information screens the IR SNIF MCD will restore any alarms that have be...

Page 22: ...ng the time of day and the refrigerant programmed for the sample area Initial Programming Once the IR SNIF MCD has completed warm up and entered Auto Zero it can be programmed While in Auto Zero or Auto Sample modes press the ENT key to access the main menu Key selections 1 2 and 3 are used to display current alarms manually initiate Auto Zero and enter the Manual Override mode These functions are...

Page 23: ...aw signal varies by less than plus or minus 10 millivolts and the autozero flag is set to 10 the monitor will not perform an autozero cycle NOTE This is effectively reducing the extreme low level sensitivity of the monitor If this feature is desired set this flag by increasing it in small steps 1 or 2 digits at a time until the monitor stops autozeroing after every zone The password flag can be se...

Page 24: ...nalog output corresponds to 0 1000 ppm This flag should be left at the factory default unless a custom measurement range has been implemented in the monitor Consult factory technical support for further information if needed Press the ENT key to move the cursor to the TWA refresh flag This flag is used to save peak ppm measurements if Trending is not implemented A TWA refresh rate of 5 minutes cor...

Page 25: ...key to set the date and time The program time date screens allows the user to set the day of the week hour minute month day and year for the real time clock RTC in the controller Entering information or pressing the ENT key will move the cursor down to the next entry Note that the RTC operates on a 24 hour clock For example to enter 2 PM enter the hour as 14 rather than 2 When the date and time ha...

Page 26: ...g refrigerants Once the appropriate gas is displayed press the ENT key to move the cursor from line two to line three Enter the tube length in feet if the tube length is greater than 100 feet If the tube is shorter than 100 feet leave the setting at the factory default of 100 When the distance has been entered press the ENT key to display the second sample setup screen Unless specified otherwise S...

Page 27: ...left or right arrow keys to change from one sample area screen to another Press the ENT key to move the arrow cursor from line one to line two To bypass or disable a sample area change the 1 to a 0 and press the ENT key Once the appropriate areas have been disabled press the ABORT key to return to the IR Setup screen again to return to the Setup Screen and again to return to normal operation The m...

Page 28: ...has been connected to external alarms fans and building systems integration can be checked using the Alarm test function of the monitor The Alarm test screen is found in the System Setup menus described previously in the start up and programming section of this manual The setup menu is accessed by pressing the ENT key Press the 4 key to enter setup followed by the password 999 From the setup menu ...

Page 29: ...own PPM level The following paragraphs describe a procedure for preparation of a refrigerant sample using pure refrigerant Three items are needed to prepare a sample A Refrigerant A Container A short piece of 1 4 Tube The Refrigerant should be available on site but if not R 134A is readily available at local stores Note that many local office supply stores sell a pressurized air duster Often this ...

Page 30: ...step The sample container should now have a measured concentration of refrigerant greater than the highest alarm level This will be used to test the end to end performance of the system in the next step Once the sample tube has been disconnected from the monitor the readings should fall slowly down to at or near zero PPM When the PPM level reaches near zero press the ENT enter key to exit Manual O...

Page 31: ...orm completely and return it to SenTech in the envelope provided This is an important step to establish warranty Please use this opportunity to make any suggestions for improvements If you are part of the user organization store this manual in a safe place If you are an installing contractor please turn over the manual to the user If you need any additional manuals call SenTech and we will be plea...

Page 32: ...er should be paper white and will turn gray or off color when dirty Replace rather than clean this filter Quarterly Performance Check Once per quarter perform the End to End system test described in the Final Checks Procedure on page 12 Commonly Ordered Parts P N Description 410144 Filter Coarse Tube 410162 Filter 5 Micron 410136 GRAY Orifice 016 410224 Diaphragm Pump Monitor Repair Most monitor r...

Page 33: ...d Options installed in the software of the monitor Optics Warm Up The Optics Warm Up Screen is displayed while the monitor is stabilizing internal temperature Currently this is set at about 9 minutes Operational Screens When the monitor completes Start Up and Optics Warmup it will enter Auto zero and then proceed to measure in Auto sample mode Under normal circumstances the monitor will cycle from...

Page 34: ...ystem will determine that it was a transient and return to normal operation Fault Mode When the monitor detects a fault condition it will enter fault mode The Main relay will energize and Trouble Alarm will be displayed in the third line of the display Alarm Modes When the monitor has sensed concentrations above the alarm trip points the associated relays will be energized The Low Main and High re...

Page 35: ...nabled choice 2 trending will not be displayed Alarm Status The alarm status screen is accessed by pressing the 1 key If any zones are in alarm the operator will have access to a series of screens formatted to show the alarm level the peak ppm and the time and date of the alarm Additional alarm screens can be accessed by pressing the left and right arrow keys If there are no alarms to display or t...

Page 36: ... PC to view and track trend information After a pause the monitor will display trend information showing date time and the first two area information Press the ENT key to display other areas for the same time Press the left arrow and right arrow to display trend information for different times Press the ABORT Key to return to normal operation Rezero The monitor can be switched into Auto zero Mode ...

Page 37: ...p screen will display 1 to enter parameters or 2 to enable or disable sample areas Press the 1 key to setup parameters for each area Press the left or right arrow keys to change from one sample area to another Press the ENT key to move the arrow cursor from line one to line two Press the left or right arrow keys to change from one gas type to another The gasses are organized in numerical order wit...

Page 38: ... short term exposure levels on a time weighted average for refrigerants SenTech recommends that under no circumstances should a refrigerant monitor be set above the short term exposure level These are recommended settings only Refer to local codes and regulations for the appropriate settings for a given application System Setup The System Setup menus are accessed from the Setup menu by pressing th...

Page 39: ...horn relay flag The horn relay flag can be set to 0 1 2 or 3 This flag changes the function of the horn relay to control an audible alarm With the flag set to the 0 the horn relay will be disabled The monitor can be programmed to allow the horn relay to be de energized while the monitor is still in alarm This feature is useful when the user is troubleshooting an alarm and wants to work in silence ...

Page 40: ...is time delay is similar to the LEAK WAIT except that the user is able to create a time definite delay rather than the ppm level defined LEAK WAIT delay The factory default setting is 0 for each delay Latch Flag Press the ENT key to move the cursor to the next entry Once the DELAY entries have been viewed press the ENT key to move the cursor to the LATCH FLAG The LATCH FLAG is used to determine if...

Page 41: ...ry Note that the RTC operates on a 24 hour clock For example to enter 2 PM enter the hour as 14 rather than 2 When the date and time have been entered press the ENT key to return to the system setup screen Trending The Trending screens enable the end user to track measured levels over time This feature will be helpful in isolating low level intermittent alarms Trending currently saves the peak ppm...

Page 42: ... Weekly trend rate the monitor will request Day of week 0 6 Hour 0 23 Minute 0 59 For Daily trend rate the monitor will request Hour 0 23 Minute 0 59 For Hourly trend rate the monitor will request Minute 0 59 ...

Page 43: ...5 is virtually unpredictable therefore in all calculations it is assumed that the leaking refrigerant will expand to fill the room with an even distribution of refrigerant This assumption will yield safer conservative calculations If the monitor sample and reference locations have been appropriately chosen the monitor will see a higher concentration than calculated from the ideal formulas Formula ...

Page 44: ...cessary to cause a measurement of 25 ppm Given air turnover of 100cfm calculate the fresh air volume in cuft hr Air flow cuft hr air flow cfm x 60 min 1 hr Air flow cuft hr 100cfm x 60 min hr 6000 cuft hr Given 6000 cuft hr calculate the leak rate that is required to maintain a measurement of 25 ppm Leak rate min cuft hr parts per million million x fresh volume cuft hr Leak rate min cuft hr 25 ppm...

Page 45: ...efore in all calculations it is assumed that the leaking refrigerant will expand to fill the room with an even distribution of refrigerant This assumption will yield safer conservative calculations If the monitor sample and reference locations have been appropriately chosen the monitor will see a higher concentration than calculated from the ideal formulas Formula Definitions ppm refrigerant conce...

Page 46: ...cessary to cause a measurement of 25 ppm Given air turnover of 225cubic meter hr calculate the leak rate that is required to maintain a measurement of 25 ppm Leak rate min cubic meter hr parts per million million x fresh volume cubic meter hr Leak rate min cubic meter hr 25 ppm 1 000 000 x 225 cubic meter hr Leak rate min cubic meter hr 005625 cubic meter hr Given 005625 cubic meter hr calculate t...

Page 47: ...10 420038 Pressure Switch 11 410136 Gray Orifice 016 not shown 12 430010 IR Bench IR SNIF MCD 13 422031 Processor Control 14 421036 Display not shown 15 421031 Keypad IR SNIF MCD and IR SNIF 1 2 3 not shown 16 410040 Socket Relay 17 410087 Relay 24VDC 18 421072 Terminal Board 8 Position 19 421042 Valve Driver Board 20 410033 Fuse Holder not shown 21 410034 Fuse 3A not shown 22 422036 Power Supply ...

Page 48: ...4 AWG Black DC Gnd 15 A3 J2 A1 PJ1 CAT 3 6Cond Control Cable 16 A3 J3 1 A1 P9 4 24 AWG Red 24 VDC 17 A3 J3 2 A1 P9 2 24 AWG Black DC Gnd 18 A3 J3 3 A1 P5 3 24 AWG Red 24 VDC 19 A3 J3 4 A1 P5 4 24 AWG White Switched Gnd Autozero Valve 20 A3 J4 1 Area 1 Gnd In 18 AWG Black Part of Valve Assembly 21 A3 J4 2 Area 1 Power In 18 AWG Black Part of Valve Assembly 22 A3 J4 3 Area 2 Gnd In 18 AWG Black Part...

Page 49: ...tched Power from High Relay 52 K4 5 TB2 7 22 AWG Black Customer Power to Horn Relay 53 K4 9 TB2 8 22 AWG White Switched Power from Horn Relay 54 TB3 1 A1 P8 1 24 AWG White Analog 1 Out 55 TB3 2 A1 P8 3 24 AWG White Analog 2 Out 56 TB3 3 A1 P8 2 24 AWG Black Ref Gnd 57 TB3 4 A1 P3 2 24 AWG White External Reset In 58 TB3 5 A1 P8 4 24 AWG Black Ref Gnd 59 TB3 6 A1 P6 1 24 AWG Blue RS485 tx 60 TB3 7 A...

Page 50: ... in Auto Zero mode If any alarms exist one two or three lights will light corresponding to RLY1 RLY2 and RLY3 Low alarm Main alarm and High alarm respectively If no power lights are lit there is a DC power fault If the power lights are lit but the RLY6 does not light or the controller is not periodically lighting the RLY6 light the control board has a fault a If there is AC power to the monitor bu...

Page 51: ...ht labeled RLY6 is switching on and off Verify that the red LED s on turning on an off according to which area is being sampled Verify that the voltages on Valve Driver Board J4 are changing from approximately 24 vdc to approximately 0 vdc according to which area is being sampled Temporarily block the air inlet and listen for the diaphragm pump to draw a vacuum If the pump does not change tone and...

Page 52: ...ea for the presence of halogenated organic chemicals Some degreasers and cleaning agents are made of organic chemicals containing chlorine fluorine or bromine Such chemicals might cause an alarm d Inspect the area for oil leaks Oil can contain trace amounts of refrigerant and will likely cause a transient alarm e Verify that there truly is no refrigerant leak in the area This includes all machines...

Page 53: ...l or has been subject to misuse alteration accident damage during transit or delivery or that such part is from a machine on which the serial number has been altered or removed then this warranty is void and of no further force or effect All decisions regarding the existence of defects in material or workmanship or other causes shall be made by SenTech s Factory Representative and shall be final a...

Page 54: ...05 21 2008 ...

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