Vulcan-Hart ML-126853, ML-126857, MHB24E, VHX24E5, ML-126852 User Manual

SERVICE MANUAL

VHX BOILER BASE SERIES

HIGH EFFICIENCY

ELECTRIC STEAMER

VHX24E ML-126852 VHX24E5 ML-126853 MHB24E ML-126857 (BASE ONLY)

VHX24E SHOWN

- NOTICE This Manual is prepared for the use of trained Vulcan Service Technicians and should not be used by those not properly qualified. If you have attended a Vulcan Service School for this product, you may be qualified to perform all the procedures described in this manual.

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.

Reproduction or other use of this Manual, without the express written consent of Vulcan, is prohibited.

For additional information on Vulcan-Hart or to locate an authorized parts and service provider in your area, visit our website at www.vulcanhart.com.

A product of VULCAN-HART LOUISVILLE, KY 40201-0696

F25154 (February 2004)

VHX SERIES STEAMERS

TABLE OF CONTENTS

GENERAL ................................................................................4

Installation, Operation and Cleaning ........................................................4

Introduction ............................................................................4

Steam Cooking.....................................................................4

Model Designations .................................................................4

Compartment Pan Capacity ...........................................................4

Cooking Compartments Control Panel ...................................................4

Boiler Control Panel ................................................................. 4

Boiler Code Descriptions .............................................................5

Water Conditioning ...................................................................... 5

Specifications ..........................................................................5

Boiler Pressure.....................................................................5

Water Supply ......................................................................5

Electrical..........................................................................6

Tools.................................................................................6

REMOVAL AND REPLACEMENT OF PARTS ....................................................7

Pressure Switch Control Box Components ...................................................7

Main Control Box Components .............................................................8

Water Level Gauge Assembly .............................................................9

Heating Elements ..................................................................... 10

Heating Element Mounting Plate .......................................................... 11

Boiler Assembly .......................................................................12

Descaler (Cathodic Protector) ............................................................ 13

Cooking Compartment Door(s)............................................................14

SERVICE PROCEDURES AND ADJUSTMENTS.................................................16

Boiler ............................................................................... 16

Inspection ........................................................................16

Clean-Out ........................................................................ 16

Deliming .........................................................................16

Descaler (Cathodic Protector) ........................................................16

Water Level Probe Housing Blowdown ..................................................... 17

Water Level Controls Test ...............................................................17

Cycling Pressure Switch Adjustment .......................................................19

High Limit Pressure Switch Adjustment .....................................................20

Boiler Fill and Cold Water Condenser Solenoid Valves .........................................20

Cold Water Condenser Thermostat Adjustment ...............................................21

Heating Element Test...................................................................22

Cooking Compartment ..................................................................22

Intake Shut-Off Valve Adjustment (Steam Flow) .......................................... 22

Door Sealing Adjustment ............................................................23

Door Latch Adjustment..............................................................23

F25154 (February 2004) Page 2 of 48

VHX SERIES STEAMERS

ELECTRICAL OPERATION.................................................................. 24

Component Function ................................................................... 24

Cabinet Base Boiler Controls .........................................................24

Cooking Compartment Controls ....................................................... 25

Component Locations ...................................................................26

Boiler Base Controls................................................................26

Cooking Compartment Controls ....................................................... 28

Water Level Controls ...................................................................29

Low Level Cut-Off & Differential Control................................................. 29

Auxiliary Low Level Cut-Off ..........................................................30

Relay Board ..........................................................................31

Layout, Legend & Diagnostic Test Points ................................................31

Schematic........................................................................ 32

Sequence of Operation ..................................................................33

Cooking Compartment Controls .......................................................34

Schematics ...........................................................................36

Boiler Base Controls................................................................36

Cooking Compartment Controls .......................................................37

Wiring Diagrams.......................................................................38

Boiler Base Controls................................................................38

Heating Element Circuits ............................................................40

Cooking Compartment Controls .......................................................41

TROUBLESHOOTING......................................................................42

CONDENSED SPARE PARTS LIST ........................................................... 48

F25154 (February 2004)Page 3 of 48

VHX SERIES STEAMERS - GENERAL

GENERAL

INSTALLATION, OPERATION

AND CLEANING

Refer to the Installation and Operation Manual for specific instructions.

INTRODUCTION

Steam Cooking

Convection cooking in pressure-less steaming compartments will steam cook fresh foods or will steam defrost and cook frozen foods providing the maximum color, flavor and nutritional value with the least expenditure of energy and labor. The pressureless steaming compartments on the VHX series, allows the operator to open and close the door anytime during a cooking cycle. The steam supply will shut off when the door is opened, then re-start when the door is closed.

Model Designations

Cooking Compartments Control Panel

Compartment Pan Capacity

MODEL

VHX24E

VHX24E5

NUMBER OF PANS

PER COMPARTMENT

24.0

32.5

61.0

34.0

52.5

Boiler Control Panel

PAN

DEPTH

(INCHES)

10 1.0

Pan Size 12" x 20"

F25154 (February 2004) Page 4 of 48

VHX SERIES STEAMERS - GENERAL

Boiler Code Descriptions

Vulcan-Hart incorporates redundant controls in compliance with the CSD-1 controls and safety devices for boiler construction on the high efficiency steamer models. A description of the code is listed below.

CSD-1 Construction - Redundant controls in the electrical safety circuits that, if tripped, must manually be reset after the condition causing the trip subsides. The controls provide low water level cut-off protection (LLCO), auxiliary low water level cut-off protection (Aux LLCO), and high pressure protection for the boiler. Additionally, the low water and high pressure safety circuits have individual indicator lights that will illuminate for a visual verification of the shutdown mode.

CSD-1 construction requires operator intervention in the event of a shutdown. The indicator lights show the operator which safety system was shutdown.

WATER CONDITIONING

Furnishing the boiler with treated water to reduce scale formation is advised. Scale formation will reduce steam output, cause premature component failure, and shorten equipment life. Most water supplies contain scale producing minerals such as calcium and magnesium. As steam is generated, the minerals remain and dissolve into the water. As the concentration of these minerals increases past a certain point, they precipitate from the water and coat the inside of the boiler, heating elements, and water level sensors. Because of the high temperature of these surfaces, the precipitated minerals bake onto them and become very difficult to remove.

This may cause several problems:

1. Reduced heat transfer efficiency.

2. Premature heating element failures.

3. False readings from water level sensors. These problems are common to any steam

equipment manufacturer, regardless of design, but can be minimized by furnishing the boiler with treated water.

Other factors affecting steam generation are iron content, amount of chlorination and dissolved gases.

The desired water properties can best be achieved by using a properly maintained water treatment

system.

The water level probes in the boiler use ions in the water to detect the water level. Do not use fully

demineralized or de-ionized water since it is non conductive and the water level can not be detected.

The use of strainers will not remove minerals from the water.

Water supplies vary from state to state and from locations within a state. Therefore, a water treatment specialist should be consulted before the installation of any steam generating equipment.

Steamers that operate over a long period of time without the benefit of a water treatment system, which have developed a heavy scale build-up, should be cleaned before using the system.

SPECIFICATIONS

Boiler Pressure

Operating - 10 to 12 psi Maximum - 15 psi

Water Supply

The fact that a water supply is potable is no guarantee that it is suitable for steam generation. The supply connection to the steam generator should be treated water and must be within the guidelines listed below. For drain water cooling only, an untreated water supply connection should be used.

Supply connection cold water Supply pressure should be 20-60 psig Hardness* less than 60 ppm Silica less than 13 ppm Total Chloride less than 4 ppm PH Range 7 to 8

Un-dissolved Solids

*17.1 ppm = 1 grain of hardness

less than 5

microns

F25154 (February 2004)Page 5 of 48

Electrical

MODELS

VHX24E,

VHX24E5,

MHB24E

NOTES:

VHX SERIES STEAMERS - COMPONENT FUNCTION

AMPERAGE

TOTAL

24 116 100 67 58 29 36 --- --- 100 87 44 42 --- --- 117 --- --48 --- --- --- 116 58

1. Amperage values in the table are nominal. Tolerance is +5/-10%.

2. Voltage values are @ 60HZ.

3. 24KW 3 phase is standard for both models. If a 24KW single phase connection is needed, the machine is field convertible at the terminal block. See heating element circuit diagram AI1388.

1 PHASE 3 PHASE

208V 240V 208V 240V 480V

TOOLS

Standard

Standard set of hand tools.

VOM with AC current tester. NOTE: Any quality VOM with a sensitivity of at

least 20,000 ohms per volt can be used.

Special

The recommended deliming chemical for the water treatment system in use, for deliming of the boiler.

Heat Exchanger Gasket (joint sealant strip, Teflon) P/N 854058-1.

Loctite 242 thread sealant or equivalent P/N 520228. Used on the top and bottom cooking compartment door screws.

3/8 x 16 tap. Used for cleaning out threads on front boiler flange.

F25154 (February 2004) Page 6 of 48

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

REMOVAL AND REPLACEMENT OF PARTS

PRESSURE SWITCH CONTROL

BOX COMPONENTS

WARNING: DISCONNECT THE

ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES.

CAUTION: Certain components in this system are subject to damage by electrostatic discharge during field repairs. A field service grounding kit is available to prevent damage. The field service grounding kit must be used anytime a control board is handled.

1. Open the cabinet base door.

2. Remove cover from pressure switch control box.

3. Disconnect lead wires from component being replaced.

4. To remove: A. Cycling pressure switch.

1) Disconnect compression fittings in the pressure supply line leading to the switch.

2) Remove mounting nuts from pressure switch mounting panel.

3) Disconnect conduit from box.

F25154 (February 2004)Page 7 of 48

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

4) Disconnect lead wires from other components as necessary then remove pressure switch mounting panel.

MAIN CONTROL BOX

COMPONENTS

WARNING: DISCONNECT THE

ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES.

1. Open the cabinet base door.

2. Remove heating element cover then main control

box cover.

5) Remove screws securing switch to panel.

B. High limit pressure switch.

1) Disconnect compression fittings from switch then remove from box.

C. Boiler fill or cold water condenser valve.

1) Turn water supply off and disconnect compression fittings from valve.

2) Remove valve bracket mounting screws.

D. Main or auxiliary water level control board

1) Compress locking tab on the board mounting standoffs and remove control board.

5. Reverse procedure to install. NOTE: Before installing the cycling pressure switch,

use pressure scale on the switch to preset the approximate cut-out (off) and cut-in (on) set points.

A. Adjust the installed pressure switch

(cycling or high limit) as outlined in SERVICE PROCEDURES AND ADJUSTMENTS.

3. Disconnect lead wires from component being replaced.

6. Check for proper operation.

F25154 (February 2004) Page 8 of 48

4. To remove: A. Contactors.

1) Release catch at the base of

B. Relays.

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

WATER LEVEL GAUGE

ASSEMBLY

WARNING: DISCONNECT THE

ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES.

1. Remove right side panel. NOTE: If right side panel is not accessible, open the

cabinet door and remove control panel to access from front.

2. Loosen packing nuts on glass tube until threads disengage then slide nut toward center of tube.

contactor and remove from DIN rail.

1) Remove from socket.

C. Relay Board.

1) Compress locking tab on the board mounting standoffs and remove control board.

5. Reverse procedure to install and check for proper operation.

NOTE:

installed, the gap between the front lip of cover and main control box must be maintained for adequate ventilation. Do not seal the gap.

When the main control box cover is properly

LEFT SIDE VIEW SHOWN

3. Slide glass tube up until it clears the bottom fitting, tilt out at the bottom and slide glass tube down to remove.

NOTE: Clean glass tube if cloudy or replace if chips or cracks are noticed.

4. Remove packing nuts from glass tube. A. A single rubber washer is installed inside

each packing nut. Clean debris from washer and inspect the rubber for cracks or hardening.

1) If rubber washer needs replacing, install a replacement rubber washer in each packing nut.

NOTE: When installing, ensure friction washer (flat) is installed inside the packing nut before rubber washer.

5. To Install: A. Slide packing nuts onto glass tube and

position each nut approximately 1" from open end on tube.

F25154 (February 2004)Page 9 of 48

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

B. Insert one end of glass tube into top gauge

fitting then align opposite end of tube with bottom gauge fitting.

C. Lower the glass tube into bottom gauge

fitting then center the tube between top & bottom gauge fittings.

D. Hold glass tube in place and hand tighten

the bottom packing nut then top.

E. Tighten each packing nut and additional

1/2 turn.

CAUTION: Do not over tighten packing nuts or damage to glass tube may occur.

6. Re-connect power to the machine.

7. Turn power switch on and allow boiler to fill. A. Press reset switch to begin heating (green

ready light on).

8. Check gauge glass for water and steam leaks. A. If necessary, slowly tighten packing nuts

until leak stops.

9. Install right side panel or front control panel (if removed).

HEATING ELEMENTS

WARNING: DISCONNECT THE

ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES.

1. Turn power switch off and allow boiler to blowdown/drain.

2. Open the cabinet base door.

3. Remove heating element cover then main control box cover.

4. Disconnect lead wires from heating element at the contactor terminals.

5. Remove mounting nuts from heating element and remove the element from boiler.

6. Clean the mating surface on mounting plate then install a replacement gasket and heating element.

7. Reverse procedure to install and check for

NOTE: When installing heating element, route the lead wires between the contactors.

F25154 (February 2004) Page 10 of 48

proper operation.

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

HEATING ELEMENT MOUNTING

PLATE

WARNING: DISCONNECT THE

ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES.

1. Remove heating elements as outlined under HEATING ELEMENTS.

Loosen mounting hardware securing control

panel to frame and lower the panel.

Loosen both conduit locking nuts (1 1/2" & 3/8") in main control box.

7. Loosen conduit nut (1 1/2") on elbow connected to main control box.

8. Remove mounting bolts for main control box. A. Lift main control box to remove from the

frame and position it to the left side.

9. Remove heating element mounting plate.

On models with cooking compartments disconnect power cord from power switch box (rear of control panel).

Disconnect pressure gauge tube

tee.

Disconnect lead wire from Aux LLCO probe.

from fitting at

only,

10. To install: A.

Clean the mating surfaces on heating element mounting plate and boiler.

B. Install new gasket on boiler side of

mounting flange.

F25154 (February 2004)Page 11 of 48

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

C. Position heating element mounting plate

with mounting studs for the element cover at the top.

NOTE: When installing heating element mounting plate

bolts as indicated to ensure the mounting plate is flush with boiler flange and gasket is evenly compressed. If bolt is not threading properly by hand, clean out the threads with a 3/8 x 16 tap.

D. Align mounting holes then press and hold

heating element mounting plate against the gasket. Install two bolts at the top and two bolts at the bottom. Hand Tighten Only.

E. Starting with the bottom bolts, tighten each

bolt a few turns at a time and alternate between the bottom and top bolts.

F. Install two bolts at the left and two bolts at

the right on the heating element mounting plate. Tighten each bolt a few turns at a time and alternate between the left and right bolts.

G. Install the four remaining bolts. Tighten

each bolt a few turns at a time and alternate between the four remaining bolts.

, install and tighten the mounting

RIGHT SIDE VIEW SHOWN

8. Remove gauge glass as outlined under WATER LEVEL GAUGE ASSEMBLY.

9. Disconnect water level probe lead wires.

10. Remove coil from blowdown/drain valve.

11. Disconnect boiler fill and cold water condenser valve water lines and remove lines.

11. To complete heating element mounting plate installation, reverse procedure from main control box removal.

BOILER ASSEMBLY

WARNING: DISCONNECT THE

ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES.

NOTE: To perform this procedure, the steamer must be accessible from all sides.

1. Turn power switch off and allow boiler to blowdown/drain.

2. Turn water supply off.

3. Remove left and right side panels.

4. Raise steamer from the bottom right side by approximately three inches to drain the remaining water from boiler. Lower steamer when boiler is empty.

5. Remove heating element mounting plate as outlined under HEATING ELEMENT MOUNTING PLATE.

6. Disconnect pressure gauge tube from gauge.

7. Disconnect air equalization tube and remove.

LEFT SIDE VIEW SHOWN

12. Remove cover from pressure switch control box and loosen conduit locking nut.

13. Remove mounting screws for pressure switch control box.

14. Disconnect pressure relief valve drain line at the valve.

15. Disconnect water level probe housing air equalization tube and remove tube.

16. Disconnect water level probe housing drain line from condenser drain box.

17. Disconnect boiler drain line from condenser drain box.

F25154 (February 2004) Page 12 of 48

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

LEFT SIDE VIEW SHOWN

18. Separate union at boiler drain.

19. On models with cooking compartments: A. Remove the left and right access panels

between the cooking compartments and boiler base.

B. Disconnect flexible steam supply line from

boiler tee to cooking compartments and remove the line.

C. Disconnect both drain lines from cooking

compartments to condenser drain box and remove the lines.

20. On models

disconnect steam supply line from boiler tee.

21. Loosen conduit nut on field connection box and slide nut down onto conduit.

22. Remove cover from field terminal box and disconnect lead wires from terminal block.

with steam generator base only,

LEFT SIDE VIEW SHOWN

23. Remove main control box and pressure switch control box from boiler base.

24. Remove bolts securing boiler to base frame then slide boiler forward to remove.

25. Remove all plumbing components from boiler and install on replacement boiler.

26. Install replacement boiler but hand tighten mounting bolts only.

27. To complete boiler installation, reverse procedure from main control box and pressure switch control box removal.

28. When all connections to boiler are made, tighten boiler mounting bolts to secure boiler to base frame.

29. Check for proper operation.

DESCALER (Cathodic Protector)

NOTE: The descalers are accessible only through

the heating element mounting plate opening in boiler.

1. Remove heating element mounting plate as outlined under HEATING ELEMENT MOUNTING PLATE.

2. Remove the two descalers hanging from the front horizontal support rod.

F25154 (February 2004)Page 13 of 48

3. To install:

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

5. Adjust the door as outlined in DOOR SEALING ADJUSTMENT under COOKING COMPARTMENT.

NOTE: Do not over tighten gasket plate screws as this will compress the gasket excessively and interfere with proper door sealing.

NOTE: Damage to the gasket sealing surface, such as nicks or cuts, will cause steam leakage.

A. On the two replacement descalers, stretch

the coiled wire (cathode) at the top to elongate the wire then form an open loop.

B. Hang the descalers on the front horizontal

support rod; one to the left of the heating elements and one to the right.

C. Position the descalers so the core (anode)

is below the minimum water level in the boiler and hanging freely.

NOTE: To function properly, the descalers must not contact the interior surfaces of the boiler or the heating elements.

COOKING COMPARTMENT

DOOR(S)

Removal

1. Remove top cover.

2. Open the door.

3. Pull hinge rod up.

4. Reverse the procedure to install, making sure the door bushings are in place.

Handle

1. Open the door.

2. Remove screws from the top and bottom of the door.

3. Pull the inner door panel out from the door housing with the gasket plate and gasket still attached.

Gasket

1. Open the door.

2. Remove screws from the gasket plate.

3. Pull the gasket plate out from the door housing and remove the gasket.

4. Position the new gasket on the gasket plate and reverse the procedure to install.

F25154 (February 2004) Page 14 of 48

VHX SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS

3. Pull the inner door panel out from the door housing with the gasket plate and gasket still attached.

4. Remove the screws from the side edge of the door that secure the latch mechanism and remove the latch from the door.

4. Remove the nuts and spacers from the handle screws and remove the handle from the door.

NOTE: When installing the spacers, the smaller diameter fits into the slot in the door and the latch lever must rest on top of the handle latch screw.

NOTE: When installing, the latch lever must rest on top of the handle latch screw.

5. Reverse procedure to install. NOTE: When installing screws at the top and bottom

of door, apply thread sealant.

5. Reverse procedure to install.

NOTE: When installing screws at the top and bottom of door, apply thread sealant.

Latch Assembly

1. Open the door.

2. Remove screws from the top and bottom of the door.

F25154 (February 2004)Page 15 of 48

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