Testing & Replacing The NAPCO 704-8000DSE Timer

NAPCO 704-8000DSE Troubleshooting Guides

NAPCO 704-8000DSE Autoclave Timer

How To Test
The NAPCO 704-8000DSE
Timer



Testing The Timer of the 704-8000DSE autoclave is not difficult. You will need a Volt/Ohm Meter to complete the test.
  • Turn Power And Dryer Switch "ON", set timer for 20 minutes and observe the timer in operation
  • If the rotation speed of the timer is not accurate, it is defective and should be replaced
  • If the time light is on, but the timer does not operate, test it with a volt meter across terminals L-1 and L-5 (See Wiring Diagram). If no voltage here, make sure all connections are tight and ther is power to the timer. Replace and if still defective, replace the timer.
How To Test The NAPCO 704-8000DSE Autoclave Timer Switches


  • First Disconnect autoclave from electrical outlet
  • Remove the wires from switch terminals - Carefully note which terminals they were removed from so you can re-connect them accurately
The Testing of the Switches as shown below is simply a continuity test. The results will be either continous (your meter reading approaches 0), or infinity (1 on a digital meter, or the needle goes to the far left on an analog meter)

Volt/Ohm Meter Connections Timer Knob Position Reading
Connect an ohmmeter accross the common terminal and N.O. terminal on switch number one Off Meter should read less than 2 ohms (continuity)
Connect an ohmmeter accross the common terminal and N.O. terminal on switch number one 5 Minutes Or More Meter should read infinity
Connect an ohmmeter accross the common terminal and N.C. terminal on switch number one Off Meter should read infinity
Connect an ohmmeter accross the common terminal and N.C. terminal on switch number one 5 Minutes or More Meter should read less than 2 OHMS (continuity)
Connect the Ohmmeter across the terminal and N.O. terminal on switch number two Off Meter should read infinity
Connect The meter across the common terminal and the N.C> terminal on Switch Number 2 Off Meter should read less than 2 Ohms (continuity)
Connect The meter across the common terminal and the N.C> terminal on Switch Number 2 20 Minutes Or More Meter should read infinity


Replace faulty timer if the above conditions are not met. Return all wires to their respective terminals

How To Replace The NAPCO 704-8000DSE Autoclave Timer

Replacing the timer is not difficult. Just use these easy to follow step-by-step instructions
  1. Disconnect the timer motor wires from the terminal block terminals marked L-1 and L-5
  2. Remove all wires from terminal switches carefully noting their location
  3. Loosen hex nut on timer shaft and remove. Lift timer out of control panel
  4. Install new timer and connect all wires
  5. Turn the timer shaft counterclockwise until it stops. This is the "OFF" position. The indicator on the knob should be adjusted to the "OFF: position
  6. Tighten the Set Screws Securely
    1. NAPCO 704-8000DSE Autoclave Repair Made Simple"