Summary of the content on the page No. 1
SERVICE MANUAL
DUAL TECHNOLOGY FINISHER
MODEL 1920 SERIES
Lincoln Foodservice Products, LLC
1111 North Hadley Road
Fort Wayne, Indiana 46804
United States of America
Phone : (800) 374-3004
U.S. Fax: (888) 790-8193 • Int’l Fax: (260) 436-0735
Technical Service Hot Line
(800) 678-9511
www.lincolnfp.com
DTFsvcman REV 1/5/07
Summary of the content on the page No. 2
SEQUENCE OF OPERATION DUAL TECHNOLOGY FINISHER 1921 208VAC 60 HZ. 3 PHASE 1922 240VAC 60 HZ. 3 PHASE POWER SUPPLY Electrical power to be supplied to the oven by a four conductor service for three phase. Black conductor is hot. Red conductor is hot. Orange conductor is hot Green conductor is ground. MAIN FAN CIRCUIT Power is permanently supplied through the 10 amp fuses, through the normally closed oven cavity hi-limit thermostat, to the normally open main power switch and to
Summary of the content on the page No. 3
SCHEMATIC DIAGRAM MODEL 1921 S/N 8001207 and Below DTF – 1920 Series Service Manual 3
Summary of the content on the page No. 4
SCHEMATIC DIAGRAM MODEL 1922 S/N 8001207 and Below 4 DTF – 1920 Series Service Manual
Summary of the content on the page No. 5
SCHEMATIC DIAGRAM MODEL 1921 / 1922 S/N 8001208 and Above DTF – 1920 Series Service Manual 5
Summary of the content on the page No. 6
TROUBLESHOOTING GUIDE 1921 208 VAC 60 HZ. 3 PHASE 1922 240 VAC 60 HZ. 3 PHASE SYMPTOM POSSIBLE CAUSE EVALUATION Oven fan will not run Incoming power supply Check circuit breakers. Reset if required. Call power co. if needed. Fuses, 10 Amp, motor and Check, replace if necessary. controls Fuse holder Check, replace if necessary. Hi-limit thermostat, Terminals are normally closed. If open, reset Oven cavity thermostat and retest. If thermostat will not hold
Summary of the content on the page No. 7
Control transformer Check for 208/240VAC supply to the primary of the control transformer. If no voltage is present, trace wiring back to the main power switch. If voltage is present, check for 24VAC at the transformer secondary. If there is primary voltage, but no secondary voltage, replace the control transformer. Oven control Check for 24VAC supply to control. If no voltage is present, trace wiring back to control transformer. If 24VAC is present, check for a read-out on the display
Summary of the content on the page No. 8
a digital multimeter. The element resistance should be as follows: 208V – 43 ohms approx. 240V – 57 ohms approx. Replace heating elements as needed. No Infrared Heating Main fan motor Check for main fan operation. If it is not operating, refer to “Oven fan will not run”. Air pressure switch Check for 208/240VAC to the air pressure switch. If no voltage is present, trace wiring back to main power switch. This normally open switch should close when the main fan is activated. Ref
Summary of the content on the page No. 9
Switch, Main Power WITH POWER OFF: Check continuity between switch terminals. Replace switch as needed. Control transformer Check for supply voltage to the primary of the control transformer. If no voltage is present, trace wiring back to the oven power relay. If voltage is present, check for 24 VAC at the transformer secondary. If there is primary voltage but no secondary voltage, replace control transformer. Air pressure switch Check for 208/240VAC to the air pressure switch. If no
Summary of the content on the page No. 10
REMOVAL, INSTALLATION AND ADJUSTMENT DUAL TECHNOLOGY FINISHER CAUTION! BEFORE REMOVING OR INSTALLING ANY COMPONENT IN THE DUAL TECHNOLOGY FINISHER, BE SURE TO DISCONNECT THE ELECTRICAL POWER SUPPLY. MOTOR, MAIN FAN - REPLACEMENT 1. Shut off power at main breaker. 2. Remove conveyor and finger assemblies from oven (see installation operations manual). 3. Remove front plenum assembly. Measure location of main fan on motor shaft for reassembly. Loosen two set screws and remove m
Summary of the content on the page No. 11
CIRCUIT BREAKER, MAIN MOTOR - REPLACEMENT 1. Shut off power at main breaker. 2. Remove rear cover. 3. Remove wires from appropriate circuit breaker and mark wires for reassembly. 4. Remove mounting nut from circuit breaker and remove circuit breaker. 5. Reassemble in reverse order and check system operation. Be sure to reset circuit breaker before operation. FUSE HOLDER - REPLACEMENT 1. Shut off power at main breaker. 2. Remove rear cover. 3. Remove wires from appropriate fuse ho
Summary of the content on the page No. 12
CAPACITOR, CONVEYOR MOTOR – REPLACEMENT 1. Shut off power at main breaker. 2. Remove control box top. Remove tube from air pressure switch. 3. Remove wiring from air pressure switch and conveyor motor capacitor and mark all wires for reassembly. 4. Remove two screws and remove air pressure switch/capacitor mounting bracket. 5. Remove capacitor from mounting bracket. 6. Reassemble in reverse order and check system operation. CONVEYOR MOTOR – REPLACEMENT 1. Shut off power at main br
Summary of the content on the page No. 13
THERMOCOUPLE MEASUREMENT TEMPERATURE (°F) D.C. MILLIVOLTS 200° 2.8 250° 4.0 300° 5.1 350° 6.0 400° 7.1 450° 8.2 500° 9.3 550° 10.4 600° 11.5 THERMOSTAT, HI-LIMIT – REPLACEMENT 1. Shut off power at main breaker. 2. Remove rear cover, remove right side heating element cover. 3. Remove hi-limit thermostat from the mounting bracket. Remove mounting nut from hi- limit thermostat. Remove hi-limit thermostat. 4. Form 90° bend in hi-limit thermostat. 5
Summary of the content on the page No. 14
voltage (120/240) and frequency (50Hz./60Hz.). After the new control is installed, the control will need to be initialized. To initialize the new control, press and hold the two center buttons on the front control panel. After the oven starts, release the buttons, the control is now initialized. Reassemble in reverse order and check system operation. 14 DTF – 1920 Series Service Manual
Summary of the content on the page No. 15
This page intentionally left blank. DTF – 1920 Series Service Manual 15
Summary of the content on the page No. 16
GENERAL VIEW MODEL 1921, 1922 A 370438 Finger housing, lower B 370441 Columnating plate, lower C 370443 Finger cover, lower left. Marked ‘LS’ D 370444 Finger cover, lower right. Marked ’RS’ E 370445 Front element cover F 370446 Front cover G 370447 Finger cover, upper H 370442 Columnating plate, upper I 370439 Finger housing, upper J 370448 Air wash panel, upper K 370449 Air wash panel, lower L 370450 ¼ turn fastener M 370451 Air return assy. N 370452 Finger support, upper O
Summary of the content on the page No. 17
DTF – 1920 Series Service Manual 17
Summary of the content on the page No. 18
CONTROL BOX VIEW MODEL 1921, 1922 A 369432 Switch, on/off B 370456 Label, control panel C 370457 Front panel D 369460 Spring, compression E 369413 Drive key F 369410 Coupling sleeve G 370106 Washer H 350259 Screw I 370458 Heating element, Infrared – 208VAC 370460 Heating element, Infrared – 240VAC J 370462 Motor, conveyor K 370383 Capacitor, conveyor motor L 369430 Air pressure switch M 370463 Top, control box N 370464 Control, main and display O 370465 Cover, rear control
Summary of the content on the page No. 19
DTF – 1920 Series Service Manual 19
Summary of the content on the page No. 20
REAR VIEW MODEL 1921, 1922 A 370466 Timer, cool down, 30 minute B 369422 Relay, main fan C 370467 Thermocouple D 370468 Cover, heating element E 370469 Motor mount F 370470 Motor, main fan S/N 8001207 and Below 4060485 Motor, main fan S/N 8001208 and Above G 370468 Cover, heating element H 370471 Cooling fan I 370472 Air switch tube assy. J 369427 Transformer, control K 370459 Heating element, 208VAC 370461 Heating element, 240VAC L 369479 Relay, Heating element M 369409 M
