SERVICE MANUAL

LG Series Fryer

LG300                                        ML-136528

LG400                                        ML-136622

LG500                                        ML-136643

– NOTICE –

This Manual is prepared for the use of trained Vulcan Service Technicians and should not be used by those not properly qualified.

This manual is not intended to be all encompassing. If you have not attended a Vulcan Service School for this product, you should read, in its entirety, the repair procedure you wish to perform to determine if you have the necessary tools, instruments and skills required to perform the procedure. Procedures for which you do not have the necessary tools, instruments and skills should be performed by a trained Vulcan Service Technician.

The reproduction, transfer, sale or other use of this Manual, without the express written consent of Vulcan, is prohibited.

This manual has been provided to you by ITW Food Equipment Group LLC (“ITW FEG”) without charge and remains the property of ITW FEG, and by accepting this manual you agree that you will return it to ITW FEG promptly upon its request for such return at                                                                                            any time in the future.

GENERAL

INTRODUCTION

This manual is applicable only to models listed on the cover page. Procedures in this manual will apply to all models unless specified. Pictures and illustrations can be of any model unless they need to be model specific.

INSTALLATION, OPERATION AND CLEANING

For detailed installation, operation and cleaning instructions, refer to the Installation & Operation Manual sent with each unit. The manual is also available online at www.vulcanequipment.com.

TOOLS

Standard

• Standard set of hand tools.
• VOM with minimum of NFPA-70E CATIII 600V, UL/CSA/TUV listed. Sensitivity of at least 20,000 ohms per volt. Meter leads must also be rated at CAT III 600V.
• Temperature tester (thermocouple type).
• ESD (Electrostatic discharge) Protection Kit.

Special

• Manometer.

SPECIFICATIONS

REMOVAL AND REPLACEMENT OF PARTS

COVER PANELS

Door

Be prepared to catch door when bottom hinge is removed.

1. Remove door hinge screws while supporting door.

Fig. 1

2. Reverse procedure to install.

Heat Shield

1. Remove DOOR.
2. Remove heat shield mounting screws.

Fig. 2

3. Angle heat shield to remove.

Fig. 3

4. Reverse procedure to install.

Back Panel

1. Remove rear panel mounting screws.

Fig. 4

2. Reverse procedure to install.

Flue Wrap

1. Remove screws securing flue wrap.

Fig. 5

2. Reverse procedure to install.

Flue Box

1. Remove FLUE WRAP.
2. Remove screws securing flue box.

Fig. 6

3. Reverse procedure to install.

BURNERS

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

1. Remove HEAT SHEILD.
2. Loosen mounting bolts at top of burner being removed.

Fig. 7

3. Push up on burner while pulling bottom of burner forward to clear burner nozzle.

4. Reverse procedure to install.

THERMOSTAT

Oil may be hot when draining fryer tank.

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

1. DRAIN FRYER TANK .                                                                                                                                                                                                                                                                                                                                               NOTE: Steps to remove Heat Shield can be skipped if back of fryer is accessible. Remove BACK PANEL to access thermostat probe packing nut.
2. Remove HEAT SHIELD.
3. Remove LEFT BURNER.
4. Pull thermostat knob (1, Fig. 8) off thermostat shaft.

Fig. 8

5. Remove thermostat mounting screws (Fig. 8) and bracket.

6. Note and disconnect thermostat wiring.

Fig. 9

7. Loosen packing nut (1, Fig. 10) and remove holding nut (2, Fig. 10).

Fig. 10

8. Remove thermostat bulb from clamp.

Fig. 11

9. Remove thermostat assembly.

10. Reverse procedure to install.

Take care not to kink thermostat capillary when installing. Wrap threads of packing nut with teflon tape to prevent leakage.

HIGH LIMIT THERMOSTAT

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

1. DRAIN FRYER TANK .
2. Remove HEAT SHIELD.
3. Remove LEFT BURNER.
4. Remove high limit mounting bracket.

Fig. 12

5. Note wires and disconnect.

Fig. 13

6. Loosen packing nut (1,Fig. 14 ) and remove holding nut (2, ).

Fig. 14

7. Reverse procedure to install.

8. Check for leaks.

THERMOPILE

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

All gas joints disturbed during servicing must be checked for leaks. Check with a soap and water solution (bubbles). Do not use an open flame.

1. Remove pilot assembly bracket.

Fig. 15

2. Note and disconnect thermopile to high limit switch wiring.

Fig. 16

3. Loosen thermopile holding nut (1, Fig. 17).

Fig. 17

4. Remove thermopile from bracket.

5. Reverse to install.

PILOT

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

All gas joints disturbed during servicing must be checked for leaks. Check with a soap and water solution (bubbles). Do not use an open flame.

1. Remove HEAT SHIELD.
2. Remove pilot assembly bracket.

Fig. 18

3. Remove pilot nut at bottom of pilot assembly.

Fig. 19

4. Disconnect pilot tubing.

5. Remove THERMOPILE.

6. Remove pilot bracket screws.

Fig. 20

7. Reverse procedure to install.

PILOT ORIFICE

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

All gas joints disturbed during servicing must be checked for leaks. Check with a soap and water solution (bubbles). Do not use an open flame.

1. Remove HEAT SHIELD.
2. Remove pilot assembly bracket.

Fig. 21

3. Remove the nut at bottom of pilot to expose the orifice.

Fig. 22

4. Pull orifice (1, Fig. 23) out and replace.

Fig. 23

5. Reverse procedure to install.

COMBINATION VALVE

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

All gas joints disturbed during servicing must be checked for leaks. Check with a soap and water solution (bubbles). Do not use an open flame.

1. Disconnect fryer from main gas supply.
2. Remove RIGHT BURNER.
3. Note and disconnect wires (1, Fig. 24) from combination valve (2, Fig. 24).

Fig. 24

4. Disconnect pilot tubing (3, Fig. 24) from combination valve.

5. Disconnect combination valve union and pressure fitting.

Fig. 25

6. Remove all pipe fittings from old valve if new valve is not supplied with fittings.

7. Reverse procedure to install.

FRY TANK

Oil may be hot when draining fryer tank.

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

1. Disconnect fryer from main gas line.
2. Remove all baskets, fryer basket hanger and crumb screen.
3. DRAIN FRYER TANK .
4. Remove HEAT SHIELD.
5. Remove FLUE WRAP.
6. Remove FLUE BOX.
7. Remove BACK PANEL.
8. Remove BURNERS and manifold bracket (Fig. 26).

Fig. 26

9. Remove THERMOSTAT.

10. Remove HIGH LIMIT THERMOSTAT.

11. Remove pilot assembly bracket.

Fig. 27

12. Lift tank up and out of cabinet.

13. Remove drain valve from tank.

14. Reverse procedure to install.

SERVICE PROCEDURES AND ADJUSTMENTS

TURNING FRYER OFF

1. Turn thermostat off.

Fig. 28

2. Keep pilot lit by turning gas valve to the “L” in pilot.

Fig. 29

3. Turn gas valve to OFF position to shut gas off to the system, including pilot.

LIGHTING PILOT

Before lighting pilot make sure tank is filled with liquid shortening. Make sure gas supply to the fryer is on.

1. Turn thermostat off.

Fig. 30

2. Turn gas control valve knob to PILOT.

3. Wait five minutes for unburned gas to vent.

4. Push and turn the gas control valve to “L” in pilot.

Fig. 31

5. While still holding knob in, light the pilot with a flame. Continue to depress knob until pilot remains lit (approximately 30 seconds), then release knob.

6. Depress and turn gas control valve knob to ON.

NOTE: If gas supply is interrupted, repeat all steps.

DRAIN FRYER TANK

Oil may be hot when draining fryer tank.

1. Turn thermostat off.
2. Turn gas valve to “L” in PILOT to keep pilot lit.

Fig. 32

3. Place container under drain valve (1, Fig. 33) to drain shortening into.

Fig. 33

4. Open the drain valve.

5. Close drain valve when fryer tank is emptied.

MILLIVOLT CONTROLS TEST

1. Verify proper gas (natural or propane) is present.
2. Check for correct wiring and secure connections.
3. Verify pilot flame is adjusted properly as outlined in PILOT ADJUSTMENT.                                                                                                                                                                                                                          NOTE: If the pilot is not lit, light pilot. Refer to: LIGHTING PILOT.

4. Allow pilot to burn for 3 to 4 minutes to stabilize.

1. 1. If pilot remains lit, proceed to step 6.
   2. If pilot will not remain lit, proceed to step 5.

5. Connect DC voltmeter to terminals TH-TP and TH of combination valve. Relight pilot, hold gas control valve knob in, and allow pilot to burn for 3 to 4 minutes to stabilize.

1. 1. lf voltage measures 450 millivolts or greater and pilot will not stay lit, replace combination valve.
   2. lf voltage is less than 450 millivolts, measure voltage at terminals NO and C of high limit.
   3. If the voltage is less than 500 millivolts, disconnect lead wire from terminal TH-TP on combination valve and remeasure voltage at the high limit.
      • If voltage is less than 500 millivolts, replace thermopile.
      • If voltage is 500 millivolts or more, replace combination valve.

6. Connect DC voltmeter to terminals TP and TH of combination valve.

7. Turn gas control valve knob to ON. Turn thermostat to a setting higher than the shortening temperature.

1. 1. If voltage measures 150 millivolts or more but the burners do not ignite, replace combination valve.
   2. If voltage is less than 150 millivolts, measure voltage between terminals NO on high limit and TP on combination valve.
      • If voltage is 200 millivolts or greater and burners do not light, replace thermostat.
      • If voltage is less than 200 millivolts and burners do not light, replace combination valve.

THERMOSTAT CALIBRATION

Oil may be hot.

If oil is present, verify it is at proper fill mark.

Check

1. Place temperature tester in center of fry tank, one inch below the surface of the oil.
2. Set thermostat to 300°F and allow temperature to stabilize.
3. Check temperature tester reading against the thermostat dial reading. If there is a variance of more than +/- 20°F (208°F to 320°F), calibration is required.

Calibration

1. Remove thermostat knob from shaft.
2. Using a small screwdriver, rotate setscrew inside the hollow shaft counterclockwise to increase temperature or clockwise to decrease temperature (1/4 turn equals approximately 18°F).
3. Allow temperature to stabilize and recheck temperature. Repeat until the temperature falls within the limits as stated in step 3 under Thermostat Calibration – Check.
4. Install thermostat knob and set dial to 350°F
5. Allow temperature to stabilize at new setting and compare temperature tester to dial setting. Recalibrate if the temperature does not fall within the range of 330°F to 370°F.
6. If temperature does not fall within the limits at both settings, replace thermostat.
7. Seal the adjustment screw after calibration is complete.

NOTE: Glyptal or ordinary Nail polish is acceptable to use as sealant.

PILOT ADJUSTMENT

NOTE: Verify the proper gas type (natural or propane) is being supplied to fryer before proceeding.

1. Turn control thermostat to off.
2. LIGHT PILOT burner and leave gas combination valve knob/extension arm in pilot position.

Allow pilot to burn for 3-4 minutes to stabilize flame. If pilot burner is not lighting or does not remain lit when gas combination valve knob/extension arm is released, see TROUBLESHOOTING. Wait 5 minutes between pilot burner lighting attempts for unburned gas to vent.

NOTE: Connect meter to thermopile leads at high limit and monitor millivolt output, with pilot properly adjusted millivolt reading should be 500mV. increase or decrease pilot flame height to achieve 500mV.

3. Verify flame does not extend beyond the outer edges of pilot shield ½”, or extends more than ½”, (Fig. 34). If adjustment is necessary continue with procedure.

Fig. 34

4. Remove the cap covering pilot adjustment screw from combination valve.

Fig. 35

• • Turn counterclockwise to increase the size of flame.
  • Turn clockwise to increase size of flame.

5. Verify pilot burner is lit.

6. Turn gas combination valve knob/extension arm to on and set control thermostat to call for heat.

If main burners do not light or pilot burner goes out, proceed to MILLIVOLT CONTROLS TEST.

BURNERS, NOZZLES AND ORIFICES

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

Burners

1. Remove BURNERS.
2. Hold burner nozzle with channel locks and remove orifice.

2. Check burners for cracks or clogged ports.

If burner ports become clogged fryer will not operate properly. If burner is cracked, it must be replaced.

1. Wash burners in warm, soapy water.
2. Hand-turn a drill bit into hole with obstruction as needed to remove blockage.

Nozzles and Orifices

1. Remove BURNERS.
2. Hold burner nozzle with channel locks and remove orifice.

Fig. 36

3. Check orifice for obstructions or damage.

4. Wash orifice in warm, soapy water.

5. Clean orifice with an orifice cleaning tool. Remove obstruction as needed to remove blockage.

6. Reverse procedure to install new burner, nozzle and orifice.

COMBINATION VALVE REGULATOR ADJUSTMENT

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

NOTE: Accurate gas pressure adjustments can only be made with gas on and burner lit. If incoming line pressure to valve is less than the minimum stated, then pressure cannot be set correctly.

Combination valve is preadjusted for natural or propane gas as specified on the rating plate. Natural gas rating is 4″ W.C., and propane rating is 10″ W.C.

1. Turn gas control valve knob to OFF.

Fig. 37

2. Remove plug from submanifold and install Manometer at this point.

Fig. 38

3. Turn on gas and LIGHT PILOT.

4. Turn gas control valve knob to ON.

5. Set thermostat so burners will come on.

6. Check pressure reading. Manifold Manometer should match pressure rating on data plate. Perform adjustment as necessary.

Adjustment

• 1. Remove adjustment screw cap.
  2. Turn adjustment screw (1, Fig. 39):

Fig. 39

• • • Counterclockwise to decrease pressure.
    • Clockwise to increase pressure.

7. Install cap and check for proper operation.

EXTENDED SHUT-DOWN

Oil may be hot.

1. Turn thermostat off.
2. Push pilot knob in and turn to OFF.
3. DRAIN FRYER TANK .
4. Clean fryer.
5. Turn off main gas shutoff valve.

Shut off the gas before servicing the unit and follow lockout / tagout procedures.

DIAGRAMS

SCHEMATIC

Fig. 40

NOTE: High limit shown tripped.

WIRING DIAGRAM

Fig. 41

ELECTRICAL OPERATION

CONTROL SYSTEM DESCRIPTION

1. The thermopile (TH) provides total control voltage for this system.
   1. One side of thermopile is connected to common (C) of high limit (HL).
   2. The other side of the thermopile is connected to normally open (NO) contacts (wire 4) of high limit.
   3. The common of high limit (below high limit trip temp) is connected through normally closed (NC) contacts of high limit, through wire 3 (wire 3 goes to TH/TP terminal on gas valve) to combination valve pilot connection common.
   4. The other side of pilot valve is connected through wire 4 (wire 4 goes to NO terminal on high limit with red wire from thermopile) to wire 1 (wire 1 goes from thermostat to high limit common terminal with white wire from the thermopile) to high limit normally open contacts which hold pilot valve open.

         NOTE: If high limit trips, connection is made from common to normally open contacts, turning off pilot valve voltage. The gas valve closes.

2. Thermostat Control

1. 1. One side of millivolt supply is connected through high limit system, as described above, to thermostat common (wire 2) of combination valve.
   2. The other side of thermopile is connected from normally open (common terminal on high limit) contacts of high limit to thermostat through wire 1 (common terminal on high limit).
   3. When the thermostat calls for heat (closed circuit) power from thermopile, it is then connected to other combination valve thermostat connection through wire 2 (to TH terminal on gas valve).
   4. If high limit trips, thermopile is connected across zero ohms, the output voltage of thermopile drops to 0.0 millivolts, and the thermostat coil of combination valve drops out, shutting the thermostat valve.

3. Total Shutdown

• 1. When high limit trips, 0.0 millivolts will read across both coils of the combination valve, causing both valves to close.
  2. Pilot relight cannot be accomplished until oil cools sufficiently to allow high limit to close.
  3. If any wire in the system is shorting, cut or broken, the system will shut down.

SYSTEM CONDITION QUICK CHECK PROCEDURE

1. Use the Pilot Lighting procedure and check millivolts (mV) at wires 3 and 4.
   1. lf the pilot lights, then pilot combination valve and high limit are good.
   2. If the pilot will not stay lit, check high limit and open the thermopile circuit. It should read 500 mV; if there are Ø volts, check high limit. If the high limit is good, replace combination valve.
   3. Check for voltage at disconnected thermopile. It should read 500 mV; if there are Ø volts, replace thermopile. Check high limit. If the high limit is good, replace combination valve.
2. Turn on thermostat; burners should light.
   1. If burner does not light, check voltage at combination valve at wires 2 (TH) and 4 (TP).
   2. If correct voltage is present, then check combination valve.
   3. If there are Ø volts, check voltage between wire 3 of combination valve and wire 1 of thermostat. If correct voltage is present, then check resistance of the thermostat contacts and continuity of wires 3 & 2.

COMPONENT FUNCTION

Thermostat Millivolt type with capillary bulb, single-throw break on temperature rise. Temperature

range of 200°F to 400°F.

Thermopile ……….. Millivolt control with 24″ capillary. Rated to generate 500 millivolts.

Combination Valve … Regulates gas flow to burner and pilot. Provides pilot safety.

High Limit Prevents overheating of fryer in the event of thermostat failure. Opens at 465°F and

automatically resets at 415°F.

TROUBLESHOOTING

TROUBLESHOOTING