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Setting Alarm as Latching or Non-Latching 

 
 
The alarms can be set as latching or Non-Latching by setting the Dip-
Switch located on lower left corner of the control module.  See figure 5.  
The dip-switch is labeled as 

Relays

 with arrow indicating the switch 

selection for latching or non-latching.  Position 1 of the Dip-switch is for 
Low alarm , position 2 is for High alarm and position 3 for High-High 
alarm.  Position 4 is not used for standard application and is reserved for 
custom application or future use.  
To set the alarm as latching move the dip-switch up or move the dip 
switch down for non-latching alarms. 
The dip-switch positions in the diagram below shows Low and High 
alarm configured as non-latching and High-High alarm set as latching 
 
 
 

 

 

RELAYS

LATCHING

NON−LATHING

1 2 3 4

 

24 

Summary of Contents for PT920-16SS

Page 1: ...MODEL PT920 16SS 16 CHANNEL GAS MONITOR CONTROLLER Operator s Manual Revision 2 0 May 2008 Pem Tech Inc Houston Texas U S A ...

Page 2: ...l of PEM TECH including but not limited to damage by accident negligence tampering or failure to operate in accordance with the procedures outlined in the Operations Manual PEM TECH s liability under no circumstances will exceed replacement of the unit claimed to be defective Tampering with the equipment and altering it for uses other than the intended use or replacement of parts not supplied by t...

Page 3: ...d obtain shipping address Properly pack the equipment before shipping Also include your complete shipping address and contact name and phone number For non warranty repairs you must provide the limit to repair costs State if a quote for repair cost is required before you can authorize the repair cost For this an additional charge may be applicable NOTE 1 For all the repairs under warranty serial n...

Page 4: ...er 12 Connecting Proximity Sensors 13 Figure 6 Typical sensor interface to Main connection 14 Board Auxiliary 10 Amps alarm relay board assembly 15 Figure 7 Auxiliary alarm board interface to PT920 15 Figure 8 Jumper settings for Control Module type 16 Wiring Audio Visual Alarms 17 Figure 9 Wiring diagram for Audio Visual alarms 17 Startup 18 Apply Power 18 Setting Control module ID Address 19 Nor...

Page 5: ...RATING 40 F to 170 F 20 C to 70 C TEMPERATURE POWER INPUT 110 220 VAC or 24 VDC HUMIDITY 0 to 100 non condensing ALARM RELAYS 4 alarm relays Form C type rated 10 Amps 1 relay for Hi Hi and 1 for Malfunction each rated 5 Amps TERMINATIONS Terminal blocks for sensor and alarm connections for wire size 16 22 AWG ALARM RESET Master alarm Reset switch to Reset Alarms SWITCH on all control modules 5 ...

Page 6: ...ching or non latching Normally open or Normally Closed contact Visual Indicators 4 Bright LEDs on the front panel to indicate alarm status Amber LED for Low Alarm Red LEDs for High and High High and Malfunction Alarm Power Input 24 VDC power input Power is supplied to remote sensor transmitter through a 2 Amp miniature fuse Power Consumption 1 Watt normal operation for each control module Max of 2...

Page 7: ...n relay contact Visual alarm indicators on the front panel Alarm RESET and BYPASS switch Optional RS485 Serial Communication for Remote data display Master Alarm Reset on the main rack assembly to Reset Alarms Programmable Relays Each control module can be programmed for 3 distinct alarm levels The alarm levels can be easily programmed using Pushbutton switch provided on the front panel of the con...

Page 8: ...ntrol Module 8 MODEL PT 920 BYPASS ALARMS NORMAL HOUSTON TX MALF RESET HIGH HI HI LOW LEDs FOR VISUAL ALARM INDICATION DIGITAL DISPLAY THUMB SCREW PUSHBUTTON SWITCH FOR ALARM RESET TOGGLE SWITCH FOR ALARM BYPASS MODULE HANDLE ...

Page 9: ...sembly can hold up to sixteen 16 PT920 series control modules On the front panel of each module a captive screw is provided to secure the module to the rack Do not use excessive force to tighten the screw Also a handle is provided to facilitate for insertion and removal of the module from the rack assembly Figure 2 PT920 16 Stainless Steel Enclosure Dimensions 9 ...

Page 10: ...ction board for the main AC line input The connections on the Din terminal blocks are labeled L N G Connect the external AC power to this terminal DC Power Input If the unit is DC powered the simply connect 24 VDC supply to the 2 pin green terminal labeled DC Iinput on the main connection board Refer to figure 3 for the location of AC and DC terminals 10 ...

Page 11: ... HI HI MALF LOW HIGH LEL MONITOR MODEL PT 920 LEL MONITOR MODEL PT 920 NORMAL BYPASS PEM TECH INC HOUSTON TX ALARMS PEM TECH INC HOUSTON TX NORMAL ALARMS BYPASS BYPASS NORMAL ALARMS ALARMS PEM TECH INC HOUSTON TX NORMAL BYPASS PEM TECH INC HOUSTON TX NORMAL ALARMS BYPASS PEM TECH INC HOUSTON TX NORMAL ALARMS BYPASS MODEL PT 920 LEL MONITOR HIGH LOW MALF HI HI RESET RESET MALF HI HI LOW HIGH RESET ...

Page 12: ... supply ground and 4 20mA input signal respectively The DC is supplied to the sensor by the control module The supply is fused through a 2 amp miniature fuse on the control module Each remote sensor should be connected by a 3 conductor shielded cable See figure 4 sensor connection 4 20mA transmitters Figure 4 Sensor connection 4 20mA Transmitter mA SIGNAL SENSOR 3 CONDUCTOR SHIELDED CABLE 4 20mA S...

Page 13: ...ns to the proximity sensors CAUTION Do not connect terminal to the sensor as it may blow the fuse on the control module Figure 5 Proximity Sensor connection to PT920 Input Module type 13 E CH 1 PROXIMITY SENSOR CONTACTS CLOSED NORMAL CONTACTS OPEN ALARM SCHEMATIC PROXIMITY SENSOR SENSOR INPUT TERMINAL ON PT920 MAIN CONNECTION BOARD CAUTION DO NOT USE CONNECTION 2 WIRES E ...

Page 14: ...9 E E E E H2S LEL CH 1 TOXIC JMP 1 CH 11 CH 10 E E CH 13 CH 12 E E E E CH 15 CH 14 E E E E CH 16 E E AS SHOWN JMP1 THRU JMP8 SELECTED AS TOXIC H2S CHANNEL TYPE JMP9 THRU JMP16 SELECTED AS LEL CHANNEL TYPE JMP 5 JMP 10 CH 2 CH 3 JMP 2 JMP 3 CH 4 JMP 11 CH 5 JMP 12 JMP 4 CH 6 JMP 13 CH 7 JMP 14 JMP 6 CH 8 JMP 15 JMP 16 JMP 7 JMP 8 SHIELDED CABLE SENSOR SIGNAL 3 CONDUCTOR mA TYPICAL SENSOR CONNECTION...

Page 15: ...bove jumpers are provided JMP 1 thru JMP 16 right above the terminal blocks for sensor input Each set of JMP 1 thru JMP 16 is designated for channel or control module 1 thru 16 If the channel or control module type is Toxic then set jumpers to TOXIC position Similarly for LEL set jumpers to LEL position See figure 8 Figure 7 Auxiliary alarm relay board interface to PT920 Main connection board 15 J...

Page 16: ... RELAY PWR DC IN V GND JMP 1 JMP 9 JMP 2 JMP 10 JMP 3 JMP 11 JMP 4 JMP 12 JMP 5 JMP 13 JMP 6 JMP 14 JMP 7 JMP 15 JMP 8 JMP 16 CH 1 CH 9 CH 2 CH 10 CH 3 CH 11 CH 4 CH 12 CH 5 CH 13 CH 6 CH 14 CH 7 CH 15 CH 8 CH 16 NC COM NO JUMPER SELECTION FOR PROPER ALARM ACTIVATION ON AUXILIARY ALARM RELAY BOARD ASSEMBLY AS SHOWN JMP1 THRU JMP8 SELECTED AS TOXIC H2S CHANNEL TYPE JMP9 THRU JMP16 SELECTED AS LEL C...

Page 17: ...tails provided by the manufacturer of the alarm devices Note that Hi Hi and FAULT alarm contacts are common to all 16 control modules and are rated 5 AMPS each Figure 9 Wiring diagram for audio and visual alarm stations to Auxiliary relay board assembly NC ALARM 4 ALARM 1 10A GND V 24VDC AL1 COM AL2 AL4 AL3 RELAY ALARM 2 ALARM 3 C NO RELAY BOARD ASSEMBLY 10AMPS AUXILIARY AUDIO VISUAL AUDIO VISUAL ...

Page 18: ... display their corresponding channel number on the display channel 1 thru 12 For example the control module in the slot 1 will display 01 module in slot 2 will display 02 and so on These channel number will flash for few seconds The channel number is also referenced as a unique Module address for proper serial communication with annunciators and data transmitters 2 Each control module will then di...

Page 19: ...dress can be changed from its default address Remember that all control modules in the control panel must have sequential and distinct addresses to communicate properly with the remote annunciator To change the module address follow the steps below 1 Position the toggle switch on the front panel of the control module to NORMAL 2 Press and hold the pushbutton switch for few seconds and the module w...

Page 20: ...ode Input Control Modules For Proximity Sensors Contact Switces Input control modules monitors the signal return through the proximity sensors The module will display CL if there is no break in the signal and switch is CLosed On the module front panel there are 2 red LED indicators for visual alarms The STATUS LED indicator is activated as soon as the module detects the break in the signal However...

Page 21: ...Settings are Alarm Alarm Level Alarm Type Low Alarm 10 Non Latching High Alarm 15 Non Latching High High 20 Non Latching Alarm Reset Once the gas concentration has dropped below the alarm level the relay will reset itself However this is true only if the relay is configured as non latching NL If the relay is configured latching then it must be reset manually To reset the latching alarm press and h...

Page 22: ... switch must be returned to NORMAL position to end alarm bypass mode and for normal module operation Programming Alarms Alarm levels must be programmed in order to activate the dry relay contacts on the main control board Alarm levels can be set anywhere between 0 and the full scale of the sensor Alarm relays can also be selected as Latching or non latching type If any alarm level is set to 00 the...

Page 23: ...or H2S or LEL the alarm level can be set between 0 and 99 If the desired alarm level is below current settings press and hold the switch The displayed level rolls over to 00 after 99 4 Release the switch when alarm level set 5 About five 5 seconds after the switch has been released the Low alarm LED will be turned off Low alarm level is set Now High alarm LED starts flashing and the display will s...

Page 24: ...g Position 1 of the Dip switch is for Low alarm position 2 is for High alarm and position 3 for High High alarm Position 4 is not used for standard application and is reserved for custom application or future use To set the alarm as latching move the dip switch up or move the dip switch down for non latching alarms The dip switch positions in the diagram below shows Low and High alarm configured a...

Page 25: ...E K1 LATCHING NON LATHING RELAYS Toggle Switch for Alarm Bypass Pushbutton Switch for Alarm Reset Thumb Screw DIP Switch to select Latching Non Latching Alarms 2 Amp Mini Fuse for Sensor DC Power Digital Display LED Indicator Board Assembly On Board Alarm Relays 25 ...

Page 26: ...rd If a fault condition occurs 1 Make sure the wires on the sensor input terminal of the main connection board are secure and connected properly 2 Check if the sensor supply fuse located on the control module is OK The fuse can be checked by verifying the DC power on the sensor terminal using a digital voltmeter If the and pin on the sensor terminal reads 24VDC then the fuse is OK See figure 10 fo...

Page 27: ... Control Module for H2S sensor PT920 L Model PT920 Control Module for LEL sensor PT920 OXY Model PT920 Control Module for oxygen sensor PT920 SO2 Model PT920 Control Module for SO2 sensor PT920 IM Model PT920 Input Control Module for Proximity sensors Call factory for detail list of control modules available for various gas sensors 27 ...

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