Tuttnauer Manual Autoclave Electrical Troubleshooting & Wiring Diagrams

For Tuttnauer Models Ending With M, MK & MKV

Basic Circuit Inspection

1. Disconnect Power To Unit
2. Set Sterilizer Controls To The Following Settings:
   • Circuit Breaker =ON
   • Power Switch = ON
   • Sterilizer Door = CLOSED
   • Timer Set = MORE THAN 10 Minutes
   • Temperature Controller = SET AT 250 DEGREES OR HIGHER
3. Set A Multimeter To OHM Scale, Then connect The Line & Neutral Terminals Of The Power Module
4. Rotate The Multi-Purpose Valve To Each Setting, Starting & Ending At 0, And Observe The Meter For The Following:
   • In The STE & EXH-DRY Positions, The Meter Should Read The Circuit Values (+ 10%) Shown In Table B Below For Each Model.
     If The Meter Reads A Much Higher Resistance Than Shown In Table B, It Is An Indication Of An Open Circuit.
     
     If The Reading Is Significantly Lower Than Shown In Table B, It Is An Indication Of A Short Circuit Or Heater Burnout
   • In The 0 And Fill Positions, The Meter Should Read A Very High Resistance - Which Indicates An Open Circuit
5. Remove Unit's Covers & Insulation Blanket. Perform A Visual Inspection Of Wiring, Terminals, & Connections.
   
   Inspect The Wiring Harness For Loose Leads & Broken Or Damaged Wires
   
   Make Any Repairs & Retest. If No Defects Found, Then Inspect Each Component & Conduct Continuity Check Of The Complete Wiring Circuit
6. Refer To The Schematic In Figure 2, Below, Check Each Circuit Component, Starting With The Circuit Breaker. Take Note Of The Following Characteristics For Each Of The Components:
   • Safety Thermostats Should Be Closed Except At High Temperature When They Open To Protect The Circuit
     
     Note: Models Built After January 1993 Have Dual Safety Thermostats, One Of Which Has A Manual Reset Button And Is Located Near The Circuit Breaker
   • Timer Must Be Turned Past 10 Minutes To Make Contact & Provide Electrical Continuity
   • Control Thermostat Must Be Set Above 212 Degrees F To Make Contact & Provide Electrical Continuity
   • Micro Switch Positions And Wiring Are Referenced On Page 9 Multi-Purpose Valve & Micro-Switches (Note: Micro-Switches Are Best Checked With An Analog Ohm Meter)
   • Heater Element Resistance Values Are Shown In Table C, Below
7. Repair All Faulty Circuits Or Components, Then Retest Unit
8. Replace Insulation Blanket & Reinstall Covers
9. Run Unit For Several Cycles & Check All Operations

*Continuity Definition: An Electrical Test For Determining Whether An Electrical Connection Is Broken

To test, (with the unit unplugged) set your volt/ohm meter on ohms ?

Place a lead on each of the contact points. If the needle on an analog meter doesn't move (stays to the left), component is bad and replacment is required. If it approaches zero, component is good. On a digital meter, if the read out is "1" component is bad.

If approaching zero, component is good.

Although The Schematic Below Applies To The Current 2340M/MK & 2540M/MK Models Of Tuttnauer Sterilizers, It Can Be Used As A Reference For Other Models As Well.

Variations To The Wiring Of Manual Models Is Common Among Tuttnauer Sterilizers/ For A List Of The Variations That Might Be Encountered When Servicing These Sterilizers, See The Listing Below The Schematic

Variations Between Tuttnauer M/MK/MKV Wiring

• Single vs Dual Circuit Breakers
• Circuit Breakers Or Fuses
• Single Or Dual Thermostat
• Wiring Of Thermostat (Manual Or Automatic Reset)
• Wiring Of Heat Light Or Dry Light
• With Or Without Door Switch
• Number Of Heating Elements Required