|
| connected to the oven control, and the display indicates |
|
| “PROBE FAIL”, disconnect the thermocouple from the |
|
| oven control and measure the resistance of the |
|
| thermocouple. The thermocouple should read approx. |
|
| 11Ω. If these readings are not achieved, replace the |
|
| thermocouple. If these readings are correct, proceed. |
| Oven control | If the thermocouple checks good, but the oven control |
|
| indicates that there is a thermocouple failure, replace |
|
| the oven control. If the oven control indicates a |
|
| temperature reading but the oven will not heat, |
|
| proceed. |
| Thermocouple | WITH POWER ON AND THERMOCOUPLE |
|
| ATTACHED TO THE OVEN CONTROL: Measure the |
|
| DC millivolt output of the thermocouple. Refer to the |
|
| thermocouple chart (located in the “Removal” section of |
|
| the manual) for proper millivolt readings. If these |
|
| readings are not achieved, replace thermocouple. |
| Oven control | If the thermocouple checks good, but there is no supply |
|
| voltage output to the mercury contactor, replace the |
|
| oven control. If there is supply voltage output to the |
|
| mercury contactor, proceed. |
| Mercury contactor | Check for supply voltage to the contactor coil. If voltage |
|
| is present and the contactor will not activate, replace |
|
| the mercury contactor Also check each contactor for |
|
| high voltage input and output. |
| Heating element(s) | Check the Amp draw on each power leg for proper |
|
| load. Check the specification plate for rating |
|
| information. If the Amp draw is high or low, check the |
|
| individual elements for opens, shorts and proper |
|
| resistance. |
|
| WITH POWER OFF; To check resistance of the |
|
| elements, remove all leads from the elements and use |
|
| a digital multimeter. |
|
| The element resistance should be as follows: |
|
| 230V – 33 ohm. |
|
| Replace heating elements as needed. |
Oven heats with | Mercury contactor | The mercury contactor has probably failed in the closed |
switch off |
| position. If there is no voltage at the operating coil, but |
|
| there is high voltage output from the contactor, replace |
|
| the mercury contactor. |
Intermittent heating | Thermal/overload of | The main fan motor is equipped with internal thermal |
| main fan motor | protection and will cease to operate if overheating |
|
| occurs. As the motor overheats and cools, this will |
|
| cause the heating system to cycle on and off |
|
| intermittently. Improper ventilation or lack of preventive |
|
| maintenance may cause this problem. Also, most of the |
|
| problem listed under “Oven will not heat” can cause |
|
| intermittent failure. |
Conveyor will not run | Incoming power supply | Check breaker, reset if required. Check power plug to |
|
| be sure it is firmly in receptacle. Measure incoming |
|
| power, call power co. if needed. |
| Fuse, 10 amp | Check, replace if necessary. |
| Fuse holder | Check, replace if necessary. |
| Check for voltage on both sides of switch. Terminals are | |
| box | normally closed. If open, reset and test oven for proper |
|
| operation. If thermostat will not hold, and control box |
|
| temperature is not exceeding 140°F (60°C), replace |
|
| thermostat. |
| Switch, main fan | With power off, check continuity between switch |
|
| terminals. Replace as needed. |
14 | Impinger II – Advantage Digital Service Manual - International |
