BLODGETT CONVEYOR STARTUP AND CALIBRATION GUIDE BLODGETT OVEN COMPANY www.blodgettcorp.com 50 Lakeside Avenue, Box 586, Burlington, Vermont 05402 USA Telephone (800) 331-5842, (802) 860-3700 Fax: (802)864-0183 PN M9437 Rev E (6/01) E 2000 --- G.S.
Table of Contents Introduction Pre-Startup Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Manual Control Startup Control Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gas Pressure Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Control Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Calibration .
Introduction Pre-Startup Requirements U.S. installations a.) Add the total BTU’s/hr of all the gas appliances on the line. b.) Convert BTU’s to cubic ft/hr using the formula Cu Ft/Hr = 1000 BTU/Hr. c.) Size the meter accordingly. OWNER’S RESPONSIBILITIES A minimum of 5 to 7 working days are needed to schedule a start-up procedure.
Manual Control Startup Control Identification The following instructions are for the standard manual control. See Figure 1 for control identification.
Manual Control Startup Gas Pressure Adjustments THE FOLLOWING STARTUP PROCEDURES MUST BE PERFORMED BY A QUALIFIED TECHNICIAN ONLY. Turn the adjusting screw on the left front side of the dual regulated valve to adjust the gas pressure. Turn the screw clockwise to raise the gas pressure and counter-clockwise to lower it. REGULATED GAS PRESSURE PRIMARY AIR ADJUSTMENT NOTE: Gas models only. NOTE: Gas models only.
Manual Control Startup Temperature Control Configuration CONFIGURATION PROCEDURES Setting the Deviation Band Alarm NOTE: Follow these configuration procedures to change the factory settings. The deviation band alarm causes the display to flash when the actual temperature varies (in either direction) from the setpoint. The deviation band alarm is adjustable to off or values from 1_F to 252_F (0.5_C to 122_C). To enter the Configuration Menus 1.
Manual Control Startup Temperature Calibration Low Limit Adjustment High Limit Adjustment 1. Bring the oven to 200_F (93_C). 2. Turn the blower and heat switches to OFF. The blower should continue to run. 3. Monitor the digital temperature control display. The blower motors should shut off within the range of 170-135_F(77-57_C). 4. To adjust the temperature, turn the low-limit potentiometer. A clockwise rotation increases the setting, counter-clockwise decreases it. See Figure 4.
Manual Control Startup Motor Control Board Adjustment Low Speed Motor Adjustment: High/low speed motor control board adjustment for 180 and 130 VDC motors 1. Turn the cook time control knob on the front panel fully counter-clockwise to increase the cook time. 2. With the motor connected (make no open circuit voltage readings) measure the voltage at the motor leads on the DC control board (A1 & A2 in Figure 5). If the voltage is not within 1 VDC of the specified voltage, continue with step 3. 3.
Manual Control Startup Belt Speed Calibration NOTE: For ovens with a 70” (178 cm) tunnel the preset constant is 5:20. For ovens with a 55” (140 cm) tunnel the preset constant is 4:08. 3. When finished, set DIP switch 1 to OFF. 4. The display reads PROG. CLOSED LOOP -- DART MICRODRIVE MDP 1. Remove the top cover. The internal dip switch is located next to the transformer. NOTE: If you change the constant, the display setting will be set to the slowest speed when you exit the programming mode.
Manual Control Startup Belt Speed Calibration OPEN LOOP Set The Belt Speed DIP Switches. The following procedure must be performed after dc voltage levels have been set and are known to be accurate. Set the DIP switches using the data from the table below. Model Hall Effect pickup identification Pickup DIP Switch Setting 60 Hz Motors NOTE: The cook time digital display should be adjusted when changing any of the system components.
Manual Control Startup Convection Blowers and Ventilation The correct motor rotation amperage draw for most Blodgett Conveyor ovens is 1 amp. If the amperage draw is less than .5 amp, check for proper motor rotation direction. 1. Remove the back of the oven body to check motor rotation direction. See Figure 9. Due to the vertical positioning of the motors in Blodgett Conveyor ovens, the motor direction is Blower Motor (Side view) VENTILATION Ignite a smoke bomb inside the oven cavity.
Computer Control Startup Control Identification The following instructions are for computer controlled oven. See Figure 10 for control identification.
Computer Control Startup Gas Pressure Adjustments THE FOLLOWING STARTUP PROCEDURES MUST BE PERFORMED BY A QUALIFIED TECHNICIAN ONLY. REGULATED GAS PRESSURE NOTE: Gas models only. 1. Let the oven heat to 510_F (266_C). Program the belt speed for 7 minutes. 2. Check the pressure at the tap on the dual regulated gas valve or at the tap on the tee valve. Incoming static gas pressure to the unit, with all the gas appliances drawing from the supply, should be a minimum of 5.5” W.C.
Computer Control Startup Convection Blowers Motor Rotation of Convection Blowers Checking the Low Limit of the Blowers: The correct amp draw for most conveyor ovens is 1 amp. For MT1828 the correct amp draw is .6 (cold) and .3 (hot). 1. Turn the oven on. Let it heat to approximately 200_F (93_C). Shut the oven off. The blowers should come back on in several seconds. 2. When the blowers shut off, turn the oven on. Press the ACT TEMP key to verify that the blowers shut off from 135-170_F (57-77_C).
Computer Control Startup Computer Configuration The cooking computer access mode displays certain computer special functions. Entering the Access Mode: 1. With the oven plugged in the display reads OFF. Press the following sequence of keys CLEAR 1 2 3 4 5 6 ENTER. 2. The display reads ACCESS. Checking the Firmware Model: 1. From the access mode press CLEAR 1 2 3 ENTER. The display scrolls through the following data then returns to the access mode.
Computer Control Startup Temperature Calibration After the oven has been cycling at the normal temperature for 30 minutes, place a temperature probe in the center of the oven to verify proper calibration. If the oven is not cycling to within ¦ 5_F (3_C) of the setpoint use the following calibration procedure. Entering the calibration mode: 1. Press the ON/OFF key until OFF is displayed. 2. Press CLEAR 1 2 3 4 5 6 ENTER to enter the access mode. The display reads ACCESS. 3.
Computer Control Startup Belt Speed Calibration CLOSED LOOP SINGLE BELT Place an object on the belt. Time its passage from entrance to exit. If the actual speed is not within ¦ 10 seconds of the setpoint calibrate as follows. NOTE: Measure the leading or the trailing edge in and out. Do not use the leading edge in and the trailing edge out. To enter the calibration mode: 1. Press the ON/OFF key until OFF is displayed. 2. Press CLEAR 1 2 3 4 5 6 ENTER. The display reads ACCESS. 3.
Computer Control Startup Belt Speed Calibration OPEN LOOP TWIN BELT Place an object on the belt. Time its passage from entrance to exit. If the actual speed is not within ¦ 10 seconds of the setpoint calibrate as follows. NOTE: Measure the leading or the trailing edge in and out. Do not use the leading edge in and the trailing edge out. Entering the Calibration Mode: 1. Press the ON/OFF key until OFF is displayed. 2.
Computer Control Startup Motor Control Board Adjustment High/low speed motor control board adjustment for 180 and 130 VDC motors 2. With the motor connected (make no open circuit voltage readings) measure the voltage at the motor leads on the DC control board (A1 & A2 in Figure 13). If the voltage is not within 1 VDC of the specified voltage, continue with step 3. 3. Turn the MIN SPEED pot clockwise to lower the voltage and counter-clockwise to raise the voltage.
PLC Control Startup Control Identification and Registration The following instructions are for both the standard manual and programmable menu PLC controls. See Figure 14 for control identification. THE FOLLOWING STARTUP PROCEDURES MUST BE PERFORMED BY A QUALIFIED TECHNICIAN ONLY. CONTROL REGISTRATION NOTE: The following control registration procedure applied to installations in North America only.
PLC Control Startup Gas Pressure Adjustments REGULATED GAS PRESSURE NOTE: Gas models only. 1. Let the oven heat to 510_F (266_C). 2. Check the pressure at the tap on the multi-function gas valve and at the tap on the tee fitting at the rear of the electrical box. See Figure 15. The manifold pressure must be 3.5” W.C. (8.7 mbar) for natural gas and 10” W.C. (25 mbar) for propane gas. This measurement should be taken at the Manifold and Pilot Pressure Tap.
PLC Control Startup Gas Pressure Adjustments COMBUSTION BLOWER PRESSURE SWITCH ADJUSTMENT PRIMARY AIR ADJUSTMENT NOTE: Gas models only. The air shutter disc on the burner blower motor, located inside the control box on top of the burner, is factory adjusted to provide the most efficient blue flame possible at sea level. 1. Visually examine the quality of the flame. 2. If it needs adjusting, increase or decrease the air mixture to attain the best flame quality. Be sure to tighten the lock nut when finished.
PLC Control Startup Gas Pressure Adjustments Circulation Blowers’ Pressure Switch (See View D) View B SW4 Blower 2 Relay Blower 1 Relay ENB 2 DIR 2 ENB 1 DIR 1 Switch 4 (See View B) Heat Relay Ignition Control Board (See View C) Interface Board (See View A) Interface Board --- View A Combustion Blower Pressure Switch (See View D) Interface Slide Tray (SG3240G) Adjustment Screw Ignition Control Board --- View C + --- Pressure Switch View D Figure 16 22
PLC Control Startup Convection Blowers Motor Rotation of Convection Blowers The correct amp draw for most gas conveyor ovens is 1 amp when the oven is hot. If the amp draw is less than .5, remove the back of the oven and check for proper motor rotation direction. See Figure 17. Due to its vertical positioning the motor direction is reference from the end of the motor (EOM) as viewed from the rear of the oven. Checking the Low Limit of the Blowers: 1. Turn the oven on. Let it heat to 200_F (93_C).
PLC Control Startup Temperature Calibration To Verify Oven Calibration 1. Place a temperature probe in the center of the oven cook cavity to verify proper calibration. 2. Start the oven and allow to cycle at the normal temperature for 30 minutes. 3. If the oven is not cycling to within ¦ 5_F (3_C) of the setpoint use the following calibration procedure. To Enter Configuration and Calibration Mode: 1.
PLC Control Startup Temperature Calibration 6. The display reads: OVEN TEMP XXXF OFFSET +(---)XXXF NOTE: The offset equals the setpoint minus the probe temperature. NOTE: The top line now displays the operating oven temperature including the offset. You can use the arrow keys to scroll to a desired offset value. Press the ENTER/RESET key to accept the offset. 7.
PLC Control Startup Belt Speed Calibration To Verify Belt Time: 1. Place an object on the belt. 2. Time its passage from entrance to exit. NOTE: Measure using the leading or the trailing edge. Do not use the leading edge in and the trailing edge out. 3. If the actual speed is not within ¦ 5 seconds of the set time, check the calibration settings as follows. To Enter Configuration and Calibration Mode: 1.
PLC Control Startup Belt Speed Calibration 6. The display reads: SELECT MOTOR RATIO XX Use the arrow keys to scroll to the correct motor ratio. Press the ENTER/RESET key to select the correct motor ratio value. 7. The display reads: TIME CAL DONE? UP---EXIT DOWN---CONT To Exit Calibration Mode: 1. Press and hold the UP ARROW and ENTER/ RESET keys simultaneously for approximately three seconds.
