Repairing The Multiport Tcd; Accessing The Detector; Removing The Filaments; Installing New Filaments - ABB PGC5000 Series Service Instructions Manual

PGC5000
PGC5000 Series Service Instructions
7.4 Repairing the multiport thermal conductivity detector
This repair should only be attempted by people who are properly trained and possess the expertise for
this repair.

7.4.1 Accessing the detector

1. Turn off power to the analyzer.
2. Turn off instrument air.
3. Turn off carrier and other gases, as applicable.
4. Allow detector assembly and columns to cool.
5. Open the main front door of the oven.
6. Open the side door of the oven (top door in Class C Oven).
7. On the wall of the side compartment, loosen the three screws on the bracket that secures the TCD assembly. (This allows
the detector assembly to rotate for ease of access.)
7. Rotate the top of the TCD to the front of the analyzer. (Tubing into and out of TCD may need to be tagged and removed).
8. Remove the TCD cover by removing eight screws securing the cover.

7.4.2 Removing the filaments

Special tool required: Adjustable 0-90 in./lb torque wrench
1. Perform "Accessing the detector."
2. Remove the clear sheaving from all filament leads.
3. Unsolder wires connected to the filaments using a 40 watt soldering iron.
4. Using a 11/32 deep well socket, loosen the gland nuts securing the filaments.
5. Continue loosening and remove the filament from the detector assembly by hand.

7.4.3 Installing new filaments

Filament Replacement Kit 865K001-1 includes a set of four filaments, four gland nuts, and a wire splice
kit.
1. Carefully install the new filaments and gland nuts; being careful to not damage the filament.
2. Install the filaments so they are facing in the direction of flow into the detector housing.
Not following the torque pattern described in the next step can result in permanent damage to the
detector block.
3. Using a 11/32 deep well socket torque each gland nut individually in a clockwise pattern in 10 IN/LB increments, until 90
in./lbs is reached on all nuts.
4. Install a one inch piece of PTFE sleeving onto each filament lead and trim leads to ¼ inch above sleeving
5. Measure the resistance of all filaments. They should be 40-42 ohms at room temperature. All filaments should be within
one ohm of each other.
6. Verify the filaments are not in contact with the detector housing. Measure the resistance from one filament lead to the
block. It should read infinity. Repeat for all filaments.
7. Leak check the filaments
8. Cap the TCD cell vents
9. Ensure the wires removed from the filaments are not in contact with the detector block or each other or remove the AC
power connectors at the bridge amplifiers.
10. Turn on carrier gas and utilities.
11. Restore power to the oven.
12. Set carrier pressures as per the data sheet.
13. Wait five to ten minutes for the pressures to equilibrate in the analyzer.
14. Check for leaks around the filaments.
SI/PGC5000-EN, Rev B
7 Subassembly repair
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