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MODEL  PT920-8FG 

 
 
 

 8 CHANNEL  

GAS MONITOR & CONTROLLER 

 

 

 
 

 

 

 
 
 
 

 

Operator’s 

Manual 

 

 

Revision 2.0 

March  2005 

 

Pem-Tech, Inc. 
Houston, Texas 
U.S.A.

 

  

Summary of Contents for PT920-8FG

Page 1: ...MODEL PT920 8FG 8 CHANNEL GAS MONITOR CONTROLLER Operator s Manual Revision 2 0 March 2005 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: ...gure 3 System Overview drawing 10 User termination control modules in Rack assembly AC or DC power Input 11 Connecting sensors to monitor 11 Alarm wiring 11 Figure 4 Sensor and alarm wiring diagram 12 Startup 13 Apply Power 13 Normal Operation and alarms Normal Operation 14 Alarms 14 Alarm Reset 14 Alarm Bypass 15 Programming Alarms 15 Programming Alarm Levels 16 Setting alarms as Latching or Non ...

Page 5: ...ING 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 3 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: ...ly 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 4 watt with all relays acti...

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: ...ack assembly can house up to eight 8 PT920 series control modules On the front panel a captive screw is provided to secure the control 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 Enclosure Dimensional drawing 9 ...

Page 10: ...PT 920 PPM H2S LOW CHANNEL 2 H2S MONITOR MODEL PT 920 NORMAL ALARMS BYPASS NORMAL ALARMS BYPASS RESET RESET MALF HI HI HIGH MALF HI HI HIGH RESET NORMAL ALARMS BYPASS HI HI MALF HIGH CHANNEL 4 H2S MONITOR MODEL PT 920 LOW PPM H2S PPM H2S LOW LEL LOW CHANNEL 5 LEL MONITOR MODEL PT 920 POWER O 1 GAS MONITOR MODEL PT920 8FG HOUSTON TEXAS NORMAL ALARMS BYPASS RESET NORMAL ALARMS BYPASS RESET MALF HI H...

Page 11: ... and 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 for remote sensor connection Alarm Wiring Figure 4 shows a typical wiring diagram for connecting alarm devices to relay contacts on the main connection board...

Page 12: ...L C LOWLEL NO HI HI C Yellow Strobe Siren Red Strobe Return or Common Voltage Power Supply for alarm devices As Appropriate Jumper select monitor gas type as appropriate Low H2S Low LEL High Alarm SENSOR SIGNAL mA Connection Board Model 920 8FG Sensor connection board Not shown completely Sensor Connection Board Typical Sensor Alarm Connections Only one sensor connection is shown for clarity ...

Page 13: ...Switch on the unit is in OFF or 0 position Flip the Power switch to ON or 1 position to turn on the power to the monitor and verify following conditions 1 All the installed control modules will display 00 for few seconds 2 Each control module will then display low high and High High alarm set points The visual alarm LED indicator will be lit while the unit displays the alarm set point 3 The contro...

Page 14: ... The user must verify the alarm set points and make changes if desired Refer to section on Programming Alarm Set points Factory Alarm 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 co...

Page 15: ...L 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 then that relay will not be activate...

Page 16: ...l scale of the sensor For example for 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 sta...

Page 17: ...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 18: ... 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 18 ...

Page 19: ...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 5 for...

Page 20: ... PT920 Series Control Modules PT920 H Model PT920 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 Call factory for detail list of control modules available for various gas sensors 20 ...

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