13
Maintenance and Servicing
To Replace Solid State Relay:
Thermo Scientific
Large Tabletop Muffle
53
4. Insert the new thermocouple into the furnace with colored beaded lead connected to the positive
(+) marked terminal and other lead to negative (-) terminal.
5. Secure connections with screws removed earlier.
6. Replace the back terminal cover.
7. Reconnect the furnace to power supply.
8. Test operation of furnace.
To Replace Solid State Relay:
1. Disconnect furnace from power supply.
2. Remove the screws on the front dial and the screws on the lower back cover.
3. Remove the upper back cover.
4. Disconnect the element lead wires and one ground wire from back of furnace. Also, disconnect
T/C lead wire from terminal block. (Note placement and connection of wires).
5. Slide control section forward and disconnect two wires from door switch. (Note placement and
connection of wires).
6. Control section can now be removed from furnace housing.
7. Disconnect the wires from the relay and remove relay. (Note placement and connection of wires).
8. Install new relay.
9. Reverse steps a - e to reassemble furnace.
10. Test operation of furnace.
To Replace Door Switch (Microswitch)
1. Disconnect furnace from power supply.
2. Remove the screws on the front dial and the screws on the lower back cover.
3. Remove the upper back cover.
4. Disconnect the element lead wires and one ground wire from back of furnace. Also, disconnect the
lead wire from terminal block (note placement and location of wires).
5. Slide the control section forward.
6. Disconnect the wires from the door switch. (Note connection and placement of wires to
Microswitch).
7. Control section can now be removed from furnace housing.
8. Remove the two screws and nuts from the Microswitch.
9. Insert new Microswitch and secure with screws and nuts removed in Step 8.
10. Slide control section back and replace the wires on the door switch.
Summary of Contents for F30400
Page 6: ...Contents 4 Large Tabletop Muffle Thermo Scientific...
Page 10: ...1 Safety Information Warning 8 Large Tabletop Muffle Thermo Scientific...
Page 14: ...2 Introduction Principles of Operation 12 Large Tabletop Muffle Thermo Scientific...
Page 18: ...4 Unpacking 16 Large Tabletop Muffle Thermo Scientific...
Page 28: ...7 Single Setpoint Models w OTP Tuning 26 Large Tabletop Muffle Thermo Scientific...
Page 50: ...11 Furnace Loading 48 Large Tabletop Muffle Thermo Scientific...
Page 62: ...15 Replacement Parts List 60 Large Tabletop Muffle Thermo Scientific...
Page 64: ...16 Ordering Procedures 62 Large Tabletop Muffle Thermo Scientific...
