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tuttnauer temp

Tuttnauer E Series Heat up Problem 

Unit turns on but produces no heat or insufficient heat 

 ♦ Start by checking for proper voltage at the wall outlet. ♦ If the unit is not getting the proper voltage from the wall outlet, this low voltage will delay or prevent the production of any heat.    The proper voltage range for 110 volt machines is between 110 and 125 volts.   The proper voltage range for 220 volt machines is between 220 and 235 volts. 


Remove the outer cabinet 


♦ With the unit unplugged, check for loose or broken wire connections at the Heating Elements.  

♦ With the unit unplugged, take an Ohm reading at the Heating Elements and compare the reading to Table 9.1 “Ohm & Amp Readings”. For instructions on how to properly check the Heating Elements [see sec. 8.2].

♦ With the unit unplugged, remove the wires between terminals 1 and 2 of the Heat SSR.  Check for an open between terminals 1 and 2 with an ohmmeter. Be sure to reverse the meter leads and check in the opposite direction also.  Repeat the procedure for terminals 3 and 4.  If an open is found, replace the Heat SSR [see sec. 10.8].

♦ Reconnect the wires to the Heat SSR, plug the unit in and turn it on, making sure there is sufficient water in the reservoir and that the door is tightly closed. Select a sterilization program, set the temperature for 273°F (134°C) and press Start on the front keypad. The unit should begin to heat up. The Heating Elements should come on and stay on until the pressure reaches approx. 25 psi. At this point, the heaters should be alternating on and off for the duration of the cycle. Verify that the heaters are getting line voltage across the terminals and drawing the proper current. Refer to Table 9.1 for the proper amperages for each model machine. For more detailed instruction on testing the Heating Elements [see sec. 8.2].  

♦ If the Heating Elements are not receiving the correct voltage or cycling properly:  While the unit is running, check the control signal between TP12 to TP1 on the Ajunc board with a voltmeter.   Check for a DC signal between 0 and 1 volt when the unit is in the heat ON mode and between 3.5 and 5 volt DC when the heaters are in the OFF mode.   If these voltages are not correct, there is a Control Problem .   


♦ If the control signal is correct at the test point, check if the correct signal is at the Heat SSR.  − A reading across terminals 3 and 4 should show 3.5 to 5 volts DC for the Heat SSR to be turned on. − A reading of 0 to 1 volt if it should be turned off  

♦ For units with control proms earlier than T93N3, check that the Temperature Safety Thermostat is not opening at the wrong Temperature. For more information [see sec. 8.8]. ♦ Check that line voltage is present at terminals 1 & 2 on the Heat SSR 

♦ Replace the Heat SSR