| increase or decrease as the DC voltage from the board increases or decreases |
| respectively. As the motor turns, it drives both the reducer gearbox and the Tach. |
| Generator. The Tach. Generator is a DC voltage generator, which supplies a voltage |
| to the DC motor control board and is used as a reference for maintaining a constant |
| conveyor speed. |
TlME/TEMP DISPLAY | The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120 |
| VAC to the primary of the 12.6 volt Transformer. The secondary output of the |
| transformer, normally 13 to 14 VAC (depending on input), with a center tap is |
| supplied to terminals 1,2, and 3 of the Time/Temp Display. The center tap is terminal |
| 2. The display works on a balanced input and center tap voltage to each leg must be |
| 1,2 the total reading. |
| The speed side of the Time/Temp. Display uses a slotted disc (cemented to tach. |
| coupling) to break the |
| motor) producing electrical pulses that are transmitted to the display. The display |
| converts these pulses into a |
| The temperature portion of the display uses a Thermistor Probe to sense oven |
| temperature. The thermistor outputs a resistance proportional to the oven |
| temperature. This resistance is then converted by the display into a temperature |
| reading. |
SEQUENCE OF OPERATIONS 1028 / 1029 / 1228 / 1229
MODEL 1028 - 380Y/220 VAC - 50 HZ - 3 PHASE
MODEL 1029 - 415Y/240 VAC - 50 HZ - 3 PHASE
MODEL 1228 - 380Y/220 VAC - 50 HZ - 3 PHASE - DUAL BELT
MODEL 1229 - 415Y/240 VAC - 50 HZ - 3 PHASE - DUAL BELT
POWER SUPPLY | Electrical Power to be supplied to the Oven by a five conductor service. |
| Black conductor is Hot |
| Red conductor is Hot |
| Orange conductor is Hot |
| White conductor is Dedicated Neutral |
| Green conductor is Ground |
|
|
MAIN FAN CIRCUIT | Electrical power is permanently supplied through 3, 50A fuses to the normally open |
| contacts of the Mercury Contactor. Power is also supplied through 1, 10A fuse to the |
| normally open contact of the Main Fan Relay, through a 1A Fuse to the normally |
| open Double Pole Main Fan Switch, and to the normally open |
| Thermostat (thermostat closes at 160°F and opens at 140°F.) Closing the Main Fan |
| Switch supplies 220 or 240 VAC to the primary of the control circuit Step Down |
| Transformer. (The transformer steps the voltage down to 120 VAC for the control |
| circuit.) 120 VAC is supplied to the coil of the Main Fan Relay. The coil of the relay is |
| energized, the normally open contacts close, energizing the Main Fan Motor. Closing |
| the Main Fan Switch also supplies power to the 12.6 VAC Transformer, the Control |
| Box Cooling Fan, and the Heat and Conveyor Switches. |
TRANSFORMER (12.6 | Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC |
VAC) | Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to |
| 14 VAC) with a center tap, and supplies power to the Time/Temp. Display. The |
| voltage from each leg of the Transformer©s secondary to the center tap should be |
| one half of the secondary voltage. |
HEAT CIRCUIT | Closing the Fan Switch and the normally open Heat Switch supplies 120 VAC |
| through the normally open Air Pressure Switch, and the normally closed |
| Thermostat (manually |
| terminal of the Temperature Control Board, the coil of the Mercury Contactor, and to |
| the Heat Indicator Light. |
TEMPERATURE | When the Heat Switch is closed, 120 VAC is supplied to the Temperature Control. |
CONTROL | The Temperature Control Potentiometer (2.5K ohm) is adjusted to desired |
| temperature. The Thermocouple will provide varying millivolts to the Temperature |
| Controller. The Temperature Controller switches the L 2 line of the Contactor coils at |
| intermittent intervals to maintain desired temperatures. |
Impinger I | 5 |