7-2
Small Vacuum Oven
VWR Collection
Section 7
Maintenance
Fusible Link
Replacement
Disconnect power and remove the back panel (edge screws) and back
insulation. Locate the bimetallic limit thermostat on the back of the oven
chamber.
1. Disconnect the fusible link from the bimetallic thermostat and control
thermostat/terminal block as connected. This is the wire assembly with
the high temperature sleeving on it.
2. Connect the new fusible link to the bimetallic thermostat and control
thermostat/terminal block.
3. Replace the insulation and back panel, then power up and test the
oven.
Disconnect power and remove the back panel (edge screws), insulation
from the back and the oven housing. The oven housing is held by screws
around the bottom edges. Lift it off and remove the rest of the insulation.
• Unscrew the heater brace nuts to remove heater braces. Pull the leads
from heater terminals and test each heater for shorts or low resistance
at the heating element sheath. An ohmmeter resistance reading that
differs greatly from 48 ohms indicates a faulty heater.
• Install a new or original heater with terminals facing down, using a
new heater brace if a new heater is installed. Attach leads to the heater,
so that wires do not touch any heated surfaces (see the wiring
schematic at the end of this manual). Tighten mounting nuts securely,
using a nickel-based anti-seize on the threads.
• Repack side as well as back insulation, and replace the back panel.
Heater Replacement
