Process Technology LUFRAN Instruction page 78

Maintenance Procedures (Continued):
4) Open the rear cabinet door.
5) Cut the lead wires coming out of the purge gas flow switch.
6) Loosen and remove the compression fitting nuts for the purge gas tubing connected
to the inlet and the outlet of the purge gas flow switch. Retain the compression nuts
and ferrules for use in step 13.
7) Remove the tubing from the inlet and outlet connections of the purge gas flow
switch. Note the inlet and outlet tubing so the replacement switch will be connected
properly.
8) Loosen the set-screw in the mounting bracket that keeps the flow switch in place.
Remove the old switch.
9) Loosen and remove the compression fittings connected to the inlet and outlet
connections of the purge gas flow switch. Retain these fittings for use in step 10.
Discard the old flow switch.
10) Re-tape and install these two compression fittings into the new purge gas flow
switch.
11) Install the new flow switch into the mounting bracket. Tighten the set-screw to hold
the switch in position.
12) Splice the lead wires from the purge gas flow switch to the two wires that were cut in
step 5. The polarity of these wires is not important.
13) Reconnect the purge gas tubing to the inlet and the outlet of the purge gas flow
switch. Use the compression nuts and ferrules retained in step 6 and the tubing
disconnected in step 7. Be sure to observe the correct polarity or the switch will not
function.
14) Turn on the purge gas supply to the unit. Check the flow switch for gas leaks.
15) Restore power to the unit.
16) Perform procedure M4-1: Purge Gas Flow Switch Inspection Procedure.
17) If the purge gas flow switch passes the inspection, the unit may be restarted and
returned to service.
M-43-01
Revision - Date: 08 – 04/06/15
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Lufran Single Outlet Manual