Detcon 110A-FB - Manual (Page 9)

Part # Model # Range Gas Type
954-230050-050 SiH4-110FB 0-50 PPM Silane
954-540050-020 SO2-110FB 0-20 PPM Sulfur Dioxide
954-430050-099 C4H8S-110FB 0-99 PPM Tetrahydrothiophene
954-EQ0050-099 C4H4S-110FB 0-99 PPM Thiophane
954-ER0050-099 C6H5CH3-110FB 0-99 PPM Toluene
954-EF0050-099 C4H6O2-110FB 0-99 PPM Vinyl Acetate
954-EL0050-099 C2H3CL-110FB 0-99 PPM Vinyl Chloride
1.16 W ARRANTY
Detcon, Inc., as manufacturer, warrants under intended normal use, each new Model 110A-FB control
enclosure to be free from defects in material and workmanship for a period of one year from the date of
shipment to the original purchaser. All warranties and service policies are FOB the Detcon, Inc. facility
located in The Woodlands, Texas.
1.17 M AINTENANCE (No special tools or test equipment required.)
TOOLS REQUIRED
01. Jeweler‘s screwdriver
02. Medium size phillips screwdriver
03. Medium size standard head screwdriver
04. Digital volt/ohm meter
DISPLAY ZERO
The potentiometer labeled "Display Zero" is used to calibrate the digital display in accordance with the 4-20
madc signal input (see figure #1). This is factory set and should not require any user adjustment. Should
fine tuning become necessary, the display should be calibrated to read "01" with a signal input of 4.16
madc.
ANALOG 4-20 MA OUTPUT CALIBRATION
The 110A-FB, 4-20 madc output is factory calibrated and tested prior to shipment and should not require
field level adjustment
(see figure #1). Should fine tuning become necessary, the digital to analog converter
is calibrated via the 4-20 MA Span and Zero potentiometer. A zero signal input of 4 milliamps should be
matched at the signal output via the ZERO potentiometer. A span signal input of 20 milliamps should be
matched at the signal output via the SPAN potentiometer.
1.18 T ROUBLE S HOOTING
FAULT INDICATOR LIGHT IS ON
01. Verify power is going out to the sensor. Using the volt/ohm meter measure 24 VDC across "+" and "–"
SENSOR terminals on the controller motherboard (see figure #4). If there is not 24 VDC, remove and
check sensor fuse (F2) for continuity (see figures #1 & #2). If open, replace with 1/2 amp micro fuse
(see parts list).
02. Verify that the 3 conductor cable from the controller to the sensor is not broken or shorted.
03. Verify that the controller is receiving a 4-20 madc signal from the sensor by placing the volt/ohm meter
in series with the signal wire "MA" and measuring a signal greater than 3.5 madc but less than 20 madc.
If out of this range, the sensor may be bad. Check sensor trouble shooting procedure in section 3.0.
DISPLAY DOES NOT LIGHT UP
01. Verify that the controller motherboard is receiving 117 VAC across terminals L1 and L2.
02. Verify that the power switch is "ON".
03. Verify that the power supply fuse is not open. First turn off the power switch. Next, remove the front
plate, the control circuit and the ribbon cable (see figure #5). Remove the power supply fuse (see figure
#6) and measure for continuity. If open, replace with 1/2 amp 3AG slow blow fuse (see parts list).
04. Verify that the power supply is outputting 24 VDC. First turn off the power switch. Next, remove the
Detcon Model 110A-FB Gas Detection System PG.9