Technical_reference - 第51页

Technical Service Manual 51 Revision Dat e: August 2004 BOTT OM HEA TER REM OVAL 1. If the Oven is belt- only , disconnec t the belt at the mas ter link and unthread the belt from the tunnel. See the procedure f or disc …

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Technical Service Manual 50 Revision Date: August 2004
TOP HEATER REPLACEMENT
1. Retrieve the heater panel for this cell and set the rear of the heater panel into place in the cell between the bracket
and the cell. Be careful not to bend the thermocouple wire. Prop the heater panel up from the front so the heater
wires can be reconnected.
2. Reconnect the wires to the panel referring to the SKETCH made when the panel and wires were removed. Use
two 11/32" wrenches so as NOT break the ceramic block or tear the foil connected to the lower (closest to the
panel) nut on the stud. Do not forget to connect the thermal switch wires.
3. Carefully place the thermocouple wire in its protective 1/8" vinyl tubing through the correct hole in the panel. If you
did NOT circle the thermocouple(s) before removing the panel, then count four rows from the left and six holes
from the front to locate the correct hole.
4. Once the thermocouple is located in its proper hole, raise the heater panel into place.
5. Replace the front panel bracket and fasten it with two Philips head screws. Remove the vinyl tubing protecting the
thermocouple.
6. Replace the left and right ICBs and fasten them in place with two Philips head screws each. Refer to the sketch of
ICB placement to locate and adjust them.
7. Carefully bend the thermocouples into the correct places and replace the clamps and screws. Tighten the screws
.
Technical Service Manual 51 Revision Date: August 2004
BOTTOM HEATER REMOVAL
1. If the Oven is belt-only, disconnect the belt at the master link and unthread the belt from the tunnel. See the
procedure for disconnecting the conveyor belt.
2. If the Oven is rail-only, disconnect the conveyor chains at the master links and unthread them from the tunnel. See
the procedure for disconnecting rails and chains.
3. If the Oven has a combination rail/belt conveyor, disconnect and unthread the chains first and then the belt from
the tunnel. See the procedures for disconnecting rails and chains and disconnecting the conveyor belt.
4. Remove the screw(s) holding the thermocouple(s) in place on the cell face. Using a permanent black marker,
circle the hole that the thermocouple(s) pass through on the heater face. Carefully straighten the thermocouple
wire and cover it with a piece of 1/8" vinyl tubing. This will aid in relocating the thermocouple when reassembling
the cell later.
5. Remove the two Philips head screws holding each ICB in place on the sides of the heater panel. Remove the
ICBs.
6. Remove the two Philips style screws holding the rear heater panel bracket. Remove the two Philips head screws
holding the front heater panel bracket. Remove the brackets.
7. Using a hex head wrench, carefully insert the short end into a hole in the heater panel and gently pull up on the
heater panel. Use the 3" putty knife to push the insulation guard clear of the heater panel.
8. Tip the heater panel on its side far enough to expose the heater wires on the inside of the cell. Block the panel
in place to remove the heater wires.
9. SKETCH the wire placement on the connections on the inside of the heater panel. They will be replaced in the
same order.
10. Remove the four wires by using two 11/32" wrenches. Use one to hold the bottom nut (closest to the panel) steady
while the other unscrews the top nut to free the wire.
IT IS VERY IMPORTANT TO USE TWO WRENCHES AND HOLD THE BOTTOM NUT STEADY BECAUSE THE
HEATER FOIL IS DIRECTLY ATTACHED TO THE STUD AT THIS LOCATION. THE CERAMIC BLOCKS ARE
FRAGILE AND EASILY BROKEN. IF THE HEATER FOIL TEARS, IT CANNOT BE REPAIRED AND THE HEATER
PANEL ASSEMBLY MUST BE REPLACED.
Technical Service Manual 52 Revision Date: August 2004
BOTTOM HEATER REPLACEMENT
1. Retrieve the heater panel for this cell and lay it into place in the cell. Be careful not to bend the thermocouple wire.
Prop the heater panel up from the front to reconnect the heater wires.
2. Reconnect the wires to the panel referring to the SKETCH made when the panel and wires were removed. Use
two 11/32" wrenches to NOT break the ceramic block or tear the foil connected to the lower (closest to the panel)
nut on the stud.
3. Carefully place the thermocouple wire in its protective 1/8" vinyl tubing through the correct hole in the panel. If the
thermocouple(s) was not marked (circled) before removing the panel, then count three rows from the right and
seven holes from the front to locate the correct hole. If the Oven has the Redundant Over-temperature Sensing
Option (ROSCO), refer to the SKETCH to locate the second thermocouple.
4. Once the thermocouples are located in their proper holes, lower the heater panel in place. Remove the vinyl tubing
from the thermocouple(s).
5. Replace the front panel bracket and fasten it down with two Philips head screws. Replace the rear heater panel
bracket and fasten it down with two Philips head screws.
6. Replace the left and right ICBs and fasten them down with two Philips head screws each. Refer to the sketch of
ICB placement to adjust them.
7. Carefully bend the thermocouples into the correct places and replace the clamps and screws. Tighten the screws.
8. Reconnect the conveyor system. See the procedures for reconnecting rails and chains and reconnecting the belt.