Fluid Components International MT86_MT86HT Manual Troubleshooting - Manual (Page 2)

FLUID COMPONENTS INTL CHAPTER 5 - TROUBLESHOOTING
Models MT86, MT86HT 5 - 2 Doc. No. 003162 Rev. F
Check Instrument Installation
Review the instrument installation information given in Chapter 2 to verify correct mechanical and electrical
installation. Be sure the connectors are firmly mated, and the wires are firmly attached to the connector. (Be sure
the wires are inserted between the metal clamps and not between the clamp and plastic connector enclosure.)
Check for Moisture
Check for moisture in the enclosures. Moisture on the electronics can cause faulty operation.
If a component of the process media is near its saturation temperature, then the component may condense on the
sensing points. Liquid on the sensing points will drive the flow measurement higher than the true measurement.
Check Application Design Requirements
Application design problems usually occur with first time application instruments, although the design should also be
checked on instruments that have been in operation for some time. If the application design does not match field
conditions, errors occur.
1. Review the application design with plant operation personnel and plant engineers.
2. Ensure that plant equipment such as pressure and temperature instruments conform to the actual conditions.
3. Verify operating temperature, operating pressure, line size, and gas medium.
Check Flow Element Placement
If there are measurement errors check for process flow irregularities. A swirling or pulsating flow can exist near
valves, elbows and other obstructions. The flow element should be placed in a straight pipe run with 20 pipe
diameters upstream of the flow element, and 10 pipe diameters down stream of the flow element.
Check Flow Element Orientation
Verify that the FLAT on the flow element is parallel to the pipe and the FLOW ARROW points in the direction of
the flow stream. If the FLAT and the FLOW ARROW are not correct, the flow measurement will not be correct.
See Chapter 2 for the instructions on proper installation.
Check Proper Flow Element Insertion Depth
The flow element's sensing points must be located at the center line of the pipe unless the factory specifies otherwise.
Improper insertion depth may cause error in the flow measurement. See Chapter 2 for the instructions on proper
installation.
Check Flowmeter Switch Positions
Switches SW1-1, SW1-2 and SW1-3 should be in the open position. Switch SW1-4 should be in the open position if
the temperature compensation mode is used. Switch SW1-4 should be in the closed position if temperature
compensation is not being used. An easy way to verify temp. comp. is used is to see if the top of the null and gain
potentiometers have been sealed. If they are sealed the flowmeter is setup to use temperature compensation. If they
are not then no temperature compensation is used. (An open switch is the switch depressed on the left or lower side
of the switch bank.
Verify that the head-select switch SW2 is set on the number that corresponds to the last sensing point that is
connected to the flow transmitter.
Verify that the switch SW4 is in the OP position.
Troubleshooting Process
Verify Delta " R" Sheets
Verify that the Delta "R" sheets in the rear of this manual match the flowmeter's serial number. If there is a
miss-match the calibration could be incorrect. Contact FCI if the proper Delta "R" Sheets are missing.