Process Technology Lufran LUF Series Manual page 50

Maintenance Procedures (Continued):
M4: Purge Gas Flow Switch, continued
Procedure M4-2: Purge Gas Flow Switch Replacement Procedure:
1) If the unit is in LOCAL mode, press the HEATER ON/OFF button to the OFF position. If the unit is in
REMOTE mode disable the heater from the customer supplied remote controller. This will also
prevent the heaters from energizing.
2) Turn OFF Power to the unit.
Vérifiez que l'alimentation électrique est coupée,
et tous les périphériques de verrouillage /
débranchement nécessaires sont correctement
installés.
3) Turn off the purge gas supply to the unit.
Vérifiez que l'alimentation en gaz de purge est
fermé, et tous les dispositifs de verrouillage /
débranchement nécessaires sont correctement
installés.
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.
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. Insure the
tubing is connected to the correct position on the new flow switch 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-43-25
Revision - Date 03-01-04-18
Verify that the electrical supply is shut off, and any
necessary lockout/tagout devices are properly
installed.
Verify that the purge gas supply is shut off, and
any necessary lockout/tagout devices are properly
installed.
49
LUF-Series Lufran Manual
Standard outlet, Standard Interface