ONICON F-2600 - Manual (Page 110)

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F-2600 & F-2700 Vortex Flow Meter Manual 02/15 - 0808-7 / 19204 Page 110
5.7 ELECTRONICS ASSEMBLY REPLACEMENT (ALL METERS)
The electronics boards are electrostatically sensitive. Wear a grounding wrist strap and make sure
to observe proper handling precautions required for static-sensitive components.
1. Turn off power to the unit.
2. Locate and loosen the small set screw which locks the larger enclosure cover in place. Unscrew
the cover to expose the electronics stack.
3. Locate the sensor harnesses which come up from the neck of the flow meter and attach to the
circuit boards. Make note of the location of each sensor connection.
Refer to figures 53 and 54. The vortex sensor connection is on the left. The temperature sensor
connection (if present) is second form the left, and the pressure sensor connection (if present) is
the right most connector. Use small pliers to pull the sensor wiring connectors off of the circuit
boards.
4. Locate and loosen the small set screw which locks the smaller enclosure cover in place.
Unscrew the cover to expose the field wiring strip. Tag and remove the field wires.
5. Remove the screws that hold the black wiring label in place. Remove the label.
6. Locate the 4 Phillips head screws which are spaced at 90o around the terminal board. These
screws hold the electronics stack in the enclosure. Loosen these screws (Note: These are captive
screws. They will stay inside the enclosure.)
7. Carefully remove the electronics stack from the opposite side of the enclosure. If the electronics
stack will not come out, gently tap the terminal strip with the screw driver handle. This will
loosen the rubber sealing gasket on the other side of the enclosure wall. Be careful that the
stack does not hang up on the loose sensor harnesses.
8. Repeat steps 1 through 6 in reverse order to install the new electronics stack.
!
WARNING
Before attempting any flow meter repair, verify that the line is not pressurized. Always remove
main power before disassembling any part of the mass flow meter.