Furnace Replacement - Ametek Thermox 2000 ATEX Series User Manual

Furnace Replacement

1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Using an ohm meter, check for short circuits of the heater coil to the
11. Reattach cell clips.
12. Reattach furnace leads (reverse the actions taken in Step 3).
7-10 | Thermox Series 2000 WDG-HPII / HPIIC - ATEX
Disconnect power from the sensor and control unit and allow unit
!
to cool before replacing parts inside the sensor.
CAUTION
To replace the furnace, do the following (see Figure 7-5):
Disconnect cell clips.
Remove the thermocouple from the furnace (see the "Thermocouple
Replacement" section in this chapter for help).
Disconnect the furnace leads from terminals R and S on the sensor
board.
Loosen the compression fitting on the underside of the cell housing
and the union fitting on the convection loop return. To prevent
stripping threads on any of the fittings, we suggest that you loosen
each in turn at small increments - don't completely loosen the one
fitting and then try to loosen the other fitting.
While holding the furnace in one hand, remove the convection loop
mounting clamp being sure to save the mounting clamp for when
you install the new furnace.
Gently pull the cell housing out of the furnace and remove the
furnace.
Slip the new furnace onto the cell housing and attach the cell hous-
ing using the convection loop mounting clamp.
Remount the cell housing (reverse the actions taken in Step 4).
Reinstall the thermocouple (reverse the actions taken in Step 2).
metal thermocouple sheath. Check that neither furnace lead is short
circuited to the metal furnace cover. The resistance should be infinite.
If you measure a short circuit, loosen the screw that secures the
thermocouple and relocate slightly until resistance is infinite.