As referenced by ASME B20.1 for use in conjunction with that standard

TABLE OF CONTENTS

Forward

1. Scope and Purpose

1.1 Equipment Covered

1.2 Equipment Not Covered

1.3 Purpose

2. Terms & Definitions

3. Applications

3.1 Areas of Use

3.2 Types of Use

4. VRC Types & Configurations

4.1 Straddle Design

4.2 Cantilever Design

4.3 Four Post Design

4.4 Double Mast Design

5. Specification Considerations

5.1 Travel

5.2 Floor to Floor Distance

5.3 Capacity, Size & Type of Load

5.4 Orientation of Loads

5.5 Loading and Unloading Methods

5.6 Platform Guarding & Accessories

5.7 Electrical Considerations

5.8 Operational Considerations

5.9 Power Units & Drive Types

5.10 Sizing a Power Unit

5.11 Locating a Power Unit

6. Installation Considerations

6.1 Surface Mount

6.2 Pit Mount

6.3 Mast or Guide Beam Support

6.4 Floor Opening and Mezzanines

7. Electrical Considerations

8. Wiring Considerations

9. Power Unit Considerations

10. Gate & Enclosure Considerations

10.1 Applicable guarding codes

10.2 Safety Gate Types

10.3 Gate Interlocks

11. Labeling

11.1 Minimum Recommended Labels

12. Maintenance Considerations

12.1 General Maintenance

12.2 Hydraulically Actuated VRC

12.3 Mechanically Actuated VRC

12.4 VRC Lift System

12.5 VRC Guide System

12.6 VRC Safety Devices

13. Operation Considerations

14. Potential Applicable Codes

15. Start-up Testing

FORWARD

Application Guidelines for VerticalReciprocating Conveyors

The Vertical Conveyor (VCC) Sub-

Committee of the Conveyor Product

Section (CPS) is a group of Vertical

Conveyor manufacturers which

comprise a substantial portion of the

companies now designing and

manufacturing Vertical Reciprocating

Conveyors (VRCs) in the United States.

This group functions within the

Conveyor Product Section of the

Material Handling Industry of America

Division of Material Handling Industry

(MHI). This latest edition of

Application Guidelines for Vertical

Reciprocating Conveyors (Guidelines)

was developed by the VCC from a

consensus developed among its members

about the descriptions, specifications and

guidelines believed to represent this

Industry's best practices. The Guidelines

present recommended safety practices

for VRC as well as information for

parties engaged in the manufacture,

marketing, purchase, inspection or use of

VRCs. The Guidelines are advisory

only and should be regarded as a guide

that the user may or may not choose to

adopt, modify or reject. They were

developed with the sole intent of

offering information to parties engaged

in the manufacture, marketing, purchase

or use of VRCs.

These Application Guidelines for

Vertical Reciprocating Conveyors were

thoroughly revised from the original

1991 version which they replace. They

were prepared as a result of the VCC

Sub-Committee's recognition of a need

to develop comprehensive safety

guidelines and establish a minimum

design criteria for when such are used in

conjunction with ASME B20.1 - The

Safety Standard for Conveyors and

Related Equipment. As a performance

standard ASME B20.1 defines the end

performance. However, it does not

provide the detail on how to accomplish

that result. These Guidelines provide

information on how the Vertical

Conveyor Industry can achieve for its

users and the operators of various VRC

designs safe application and proper

utilization. The acceptance or use of

these Guidelines is completely

voluntary. Its existence does not in any

respect preclude anyone, whether he has

approved the Guidelines or not, from

manufacturing, marketing, purchasing,

or using products, processes, or

procedures not conforming to these

Guidelines.

DISCLAIMER

MATERIAL HANDLING INDUSTRY (MHI), CPS ANDVCC, AND THEIR MEMBERS ASSUME NO

RESPONSIBILITY AND DISCLAIM ALL LIABILITY OFANY KIND, HOWEVER ARISING, AS A RESULT OF

ACCEPTANCE OR USE OR ALLEGED USE OF THESEGUIDELINES. USER SPECIFICALLY UNDERSTANDS

AND AGREES THAT MHI AND CPS AND VCC ANDTHEIR OFFICERS, AGENTS, AND EMPLOYEES SHALL

NOT BE LIABLE UNDER ANY LEGAL THEORY OFANY KIND FOR ANY ACTION OR FAILURE TO ACT

WITH RESPECT TO THE DESIGN, ERECTION,INSTALLATION, MANUFACTURE, PREPARATIONFOR SALE, SALE, CHARACTERISTICS, FEATURES,

OR DELIVERY OF ANYTHING COVERED BY THESEGUIDELINES. ANY USE OF THIS INFORMATIONMUST BE DETERMINED BY THE USER TO BE IN

ACCORDANCE WITH APPLICABLE FEDERAL, STATEAND LOCAL LAWS AND REGULATIONS.

MHI AND CPS AND VCC MAKE NO WARRANTIES OFANY KIND, EXPRESS, IMPLIED OR STATUTORY, INCONNECTION WITH THE INFORMATION IN THESEGUIDELINES. MHI AND CPS AND VCCSPECIFICALLY DISCLAIM ALL IMPLIEDWARRANTIES OF MERCHANTABILITY OR OFFITNESS FOR PARTICULAR PURPOSE.

BY REFERRING TO OR OTHERWISE EMPLOYINGTHESE GUIDELINES, THE USER AGREES TO DEFEND,PROTECT, INDEMNIFY, AND HOLD MHI AND CPSAND VCC AND THEIR OFFICERS, AGENTS, ANDEMPLOYEES HARMLESS FROM AND AGAINST ALLCLAIMS, LOSSES, EXPENSES, DAMAGES, ANDLIABILITIES, DIRECT, INCIDENTAL, ORCONSEQUENTIAL, ARISING FROM ACCEPTANCE ORUSE OR ALLEGED USE OF THIS STANDARD,INCLUDING LOSS OF PROFITS AND REASONABLEATTORNEYS' FEES WHICH MAY ARISE OUT OF THEACCEPTANCE OR USE OR ALLEGED USE OF THESEGUIDELINES. THE INTENT OF THIS PROVISION ANDOF THE USER IS TO ABSOLVE AND PROTECT MHIAND CPS AND VCC AND THEIR OFFICERS, AGENTS,AND EMPLOYEES FROM ANY AND ALL LOSSRELATING IN ANY WAY TO THESE GUIDELINES,INCLUDING THOSE RESULTING FROM THE USER'SOWN NEGLIGENCE.

Suggestions with respect to these

Guidelines are welcomed. They should

be sent to the Conveyor Product Section

of Material Handling Industry of

America, 8720 Red Oak Boulevard,

Suite 201, Charlotte, NC 28217-3992.

Scope and Purpose

1.1 Equipment Covered

This Application Guideline is intendedto specifically apply to VerticalReciprocating Conveyors (VRC) whichare designed to raise and lower materialsfrom one elevation to another. They areprimarily hydraulically or electro-mechanically activated and powered.VRC’s are mounted in a stationaryposition. The equipment may perform astand-alone function or may beincorporated into an automated system.Equipment covered by this ApplicationGuideline falls under ASME/ANSIB20.1-Safety Standard for Conveyorsand Related Equipment.

1.2 Equipment Not Covered

This Application Guideline does notrelate to:

• Aerial work platforms used forbuilding maintenance andconstruction purposes such ascovered by ANSI/SIA A92

• Elevators and equipment of any typeas covered in ANSI/ASME A17.1

• Industrial scissors lifts as covered inANSI MH29.1

• Any portable lifts not permanentlyattached to a building structure

• Any lift designed to transportpersonnel

• Lifts for handicapped access asdescribed by ANSI/ASME A18

• Inclined conveyors

1.3 Purpose

The purpose of this ApplicationGuideline is to provide designers,sellers, installers, inspectors, owners,users and governing bodies with a sourceof information for consideration indesign, application, configurationcriteria as well as recommendedminimum requirements for design,specification and labeling.

2. Terms & Definitions

2.1 Approach Ramp: An access rampused to load on/off of a platform.

2.2 Authorized Person: Trained orqualified personnel approved or assignedto perform a specific duty or duties.

2.3 Back Frame: The vertical portionsof the carriage on a cantilever VRC.

2.4 Back Stop Panel: Panel that isinstalled opposite the loading edge atupper loading levels of a VRC platform,to prevent personnel and/or the loadfrom falling to the lower level. Thisterm should not be confused with theterm “backstop” as defined inANSI/ASME B20.1

2.5 Cable: Wire rope.

2.6 Cantilever: A style of VRC wherethe carriage rides along masts that arelocated on the same side of the carriage.This style lift can accommodate “C”,“Z” and 90 degree loading patterns.

2.7 Capacity: The maximum load forwhich the VRC is designed.

2.8 Carriage or Carrier: The entirestructural assembly that travels on themast and carries the load.

2.9 Constant Pressure Push Button:A push button, which to activate, mustremain pressed by the operator in orderto perform a desired operation.

2.10 Controls: Any electrical deviceused in the operation or control of a lift.Normally includes push button stations,control box, limit switches, interlocks,etc.

2.11 Control Voltage: The secondaryvoltage, which typically originates at atransformer and provides power to thecontrol devices.

2.12 Conveyor, VerticalReciprocating: A reciprocating poweror gravity actuated lifting device (notdesigned to carry passengers or anoperator) that receives objects on acarriage and transports these objectsvertically from one elevation to another.

2.13 Cylinder: A device, whichconverts fluid power into linear forceand motion. It usually consists of amovable element such as a piston andpiston rod, plunger or ram, operatingwithin a cylindrical bore.

2.14 Direct acting cylinder: Thecylinder or ram transmits lifting forcedirectly to the carriage rather thanthrough the use of cables, sheaves orchains.

2.15 Drift: The distance a lift platformwill slowly drop due, usually, to slight

internal leaks in a hydraulic system ormechanical slippage of a motor brake.

2.16 Enclosure (lift guarding):Structure surrounding a VRC to preventoutside interference with its normaloperation and to safe guard personnel.Typically 8’ high panels composed ofexpanded metal or other materials thatwill prevent a 2” diameter ball frompassing through. This is a requirementof ASME/ANSI-B20.1.

2.17 Explosion Proof: Electricaldevices that are designed to operatesafely in a specific location or areawhere potentially explosiveenvironments can or do exist.

2.18 Gate: A device that opens andcloses manually or automatically toallow access to the carriage for loadingand unloading. It is normally a swing,sliding, or vertical acting deviceconstructed of similar expanded metal asthe enclosure.

2.19 Guarded by Location: Describesmoving parts so protected by theirremoteness from the floor, platform,walkway, or other working level, or bytheir location with reference to frame,foundation, or structure as to reduce theforeseeable risk of accidental contact bypersons or objects. Remoteness fromforeseeable, regular, or frequentpresence of public or employedpersonnel may in reasonablecircumstances constitute guarding bylocation.

2.20 Interlock (Gate/Door): A lockingsystem used on the access doors or gatesof a VRC to prevent its operation unlessall such doors/gates are closed and to

prevent the opening of any suchgate/door unless the VRC carrier orcarriage is present at that particularlanding or opening.

2.21 Intermediate Stop: Usually a stopbetween top and bottom floors or levels.

2.22 Landing: A permanent-workingsurface at a fixed elevation used forloading/unloading a lifting device.

2.23 Limit Switch: An electricalcontrol device by which the position ormovement of the lift may be controlledwithin predetermined limits.

2.24 Load Height: The maximumheight of material for which the VRChas been designed.

2.25 Load Pattern: A method todescribe the direction a load will bemoved on and off a platform at differentlandings or levels.

2.26 Mast(s) or Guide Beams: Thevertical members by which the carriageis guided throughout its vertical travel.

2.27 Mechanical Stop: A mechanicalmeans of stopping travel at apredetermined position.

2.28 Momentary Contact PushButton: A push button, which only hasto be pressed for an instant to activatethe desired operation.

2.29 Non-operating End: The side(s)of a carriage or carrier not used forloading/unloading. Handrails withmidrail and kickplate are normallysupplied as minimum guarding.

2.30 Operating End: The side(s) of theplatform used for loading/unloading.The side(s) are normally equipped with asafety chain as minimum guarding.

2.31 Platform: The horizontal floorsurface of the carriage or carrier wherethe load is placed.

2.32 Pressure Switch: A pressuresensing switch that can be set to trip at apredetermined pressure. When thispressure setting is reached it willactivate, thus providing a signal to thecontrol circuit and stopping the pumpmotor.

2.33 Primary Voltage: The mainelectrical power being supplied foroperation of the equipment.

2.34 Push Button Station: The wallmounted or hand held device used tocontrol the operation of the equipment.

2.35 Qualified Person: A person, whoby possession of a recognized degree,certificate, professional standing, orskill, and who by knowledge, trainingand experience, has demonstrated theability to deal with problems relating tothe subject matter, the work, or theproject.

2.36 Roll off Panel: A structure used onupper levels to prevent personnel and/orproducts from falling off the platformwhen loading or unloading.

2.37 Sheave: Device (pulley) which isdesigned to guide or change the directionof a wire rope or cable.

2.38 Slack Chain Device: Device usedto signal, interrupt power or alert of aslack chain condition.

2.39 Spliced Carriage: Carriage that issplit or in several pieces and will be fieldassembled. This design facilitates ease ofinstallation and handling.

2.40 Spliced Mast or Guide Beam:Mast or Guide Beam that is fabricatedand delivered in two or more sectionsnecessitated by manufacturing,handling, or installation constraints.

2.41 Straddle: A style of VRC wherethe carriage rides suspended betweentwo masts that are located on oppositesides of the carriage. This style of liftwill accommodate “C” and “Z” typeloading patterns.

2.42 Velocity Fuse: A hydraulic valve,which in the event of a severed hose,will lock the oil in the cylinder andprevent the cylinder from descending.

2.43 VRC: Abbreviation for VerticalReciprocating Conveyor.

3. Applications

3.1 Areas of Use

3.1.1 Mezzanines: With the increasedusage of vertical space in buildingstoday, vertical conveyors are anexcellent choice for moving materialsfrom first floor level to the mezzaninelevel. VRC’s may be installed eitheralong the edge of a mezzanine orthrough a hole cut in the mezzanine floordepending on the user’s preference andthe handling requirements. Thisprecludes the need to wait for, and tieup, expensive portable equipment forplacing materials directly on the mezzanine or in a staging area.

3.1.2 Multi-floor Buildings: With theincreased costs of land and buildingconstruction, new companies for theirstart-up expansion are utilizing olderbuildings. The use of a VRC canstreamline a manufacturing orwarehousing operation in this type offacility and make it a less expensive,productive facility. The addition of aVRC can relieve the burden of movingmaterials and cargo on an existingelevator thus freeing up the elevator forthe purpose it was intended, movingpeople. The VRC can also bestrategically located within the buildingto provide vertical transportation ofgoods or materials within closeproximity of the production or storagearea or it can be installed on the outsidewall of the building if space is notavailable inside.

3.1.3 Existing Shaft: A VRC may beinstalled in an existing shaft if theapplication requires moving only goodsor materials and not personnel. 3.1.4 Automated Systems: Theplatform of a VRC may be equippedwith a powered roller conveyorassembly, a gravity conveyor with adrop lock assembly, a chain transferconveyor assembly, a turntable deviceand/or a pusher assembly and caninterface with conveyor lines, single ormulti-level rack system, or a transport.The controls can be so designed suchthat the carriage or carrier can receivethe load automatically, deliver productsto a pre-selected destination and thenreturn to its original positionautomatically.

3.2 Types of Use

3.2.1 Manual loading and unloading ofboxes, cartons, and various othermaterials.

3.2.2 Pallet loads using pallet handtrucks, motorized pallet trucks, orforklift trucks. Note the VRC’s capacitywhen loading and unloading with heavyloading devices. The VRC must bedesigned and installed to tolerate theload plus the loading device.

3.2.3 Four wheeled carts, hand trucks,wheeled bin trucks, wheeled trashtrucks, gondolas, etc.

3.2.4 Automated loading with the useof gravity, chain transfer sections orpowered conveyors, turntables, pushers,etc. for the handling of pallet or slipsheet loads into or out of storagefacilities, multilevel small order pickingoperations, for ceiling leveltransportation of products from onefacility to another, and various otherapplications where multilevel continualflow is required and minimum floorusage is a requirement.

3.2.5 The transfer of AutomaticGuided Vehicles (AGV’s) from onefloor level to another.

4. VRC Types andConfigurations

4.1 Straddle Design

4.1.1 This design type, as illustratedabove, places the carriage between theguide beams and applies the load forcesin the vertical direction along the lengthof the guide beams.

4.1.2 This design allows for greaterlifting capacities, larger platform sizes,and the ability to handle higher rolloverforces created during loading andunloading. The method of loading andunloading and the resultant rolloverforces must be specified by the ownerand accommodated by the manufacturerwhen the equipment is designed andmanufactured.

4.1.3 A disadvantage of the straddledesign is its limitation to loading andunloading from the two ends oppositeeach other.

4.2 Cantilever Design

4.2.1 This type of VRC, as illustratedabove, has the load carrying carriagemounted out in front of the mast or guidebeams.

4.2.2 Four advantages of the cantileverdesign are: 1) the design allows access tothree sides of the platform for loadingand unloading, 2) the carriage overheadclearance may not be restricted by anoverhead structural member as on astraddle design, 3) the overall height ofthe unit may be less than for otherdesigns, and 4) the footprint of theequipment may be reduced requiring lessspace for a given size carriage or carrier.These criteria may vary based on theparticular application and should bereviewed on a case by case basis withthe manufacturer.

4.2.3 Two disadvantages to this designare: 1) the loading creates an overturningmoment on the guide structure whichmust be translated to the surroundingbuilding or structure via bracing and 2)platform sizes and capacities may belimited due to the positioning of the loadin relation to the guide structure.

4.3 Four Post Design

4.3.1 The VRC design as illustratedabove has the platform mounted withinthe four guide beams.

4.3.2 An advantage this design is theopportunity to use very large platformsizes and very high capacities.

4.3.3 The four post design channels theloads vertically through the guide beamsand to the floor. Bracing isrecommended to handle the lateral loadsimposed based on the particularapplication.

4.3.4 This design allows access fromfour sides for loading and unloading.

4.3.5 A disadvantage is a largerfootprint.

4.4 Double Mast Design

4.4.1 This design is similar to the fourpost in that it requires the use of fourguide beams, but the difference is thatthe carriage or carrier is cantileveredbetween the two sets of masts and thatthe capacity and platform sizes are lesswhen compared to the four post design.

4.4.2 Two advantages of this design are1) larger carriage or carrier sizes areallowable compared to the two postdesign, and 2) the overhead clearance ofthe load height is unhindered bystructural cross members compared tothe four post design.

4.4.2 Two disadvantages of this designcompared to the four post design are1)loading is limited to the two ends and2) platform sizes are not as large for agiven capacity.

5. Specification Considerations

5.1 Travel The difference in elevationbetween the top surface of the carriageor carrier at the bottommost level andthe top surface of carrier or carriage atthe uppermost level-regardless ofwhether the unit is pit or surfacemounted.

5.2 Floor-to-Floor Distance Thedistance from one finished floor level tothe next finished floor level.

5.3 Capacity, Size and Type of load Capacity not only refers to the weight

of the load but also the physical size andconfiguration of the load. Types ofloads are typically: individual boxes anditems, palletized loads, drums, pushcarts,and trucks, etc. The platform should besized to handle the largest loads withadequate clearances for handlingoperations. The capacity should take inconsideration the weight of theequipment used for loading andunloading operations in addition to theweight of the heaviest load. If theloading and unloading process has thepotential for intended or unintendedimposition of large horizontal forcesthis must be taken into account duringdesign.

5.4 Orientation of LoadsThe traffic pattern of the loads forloading and unloading will determinewhich style of VRC configuration can beused. There are 3 basic load trafficpatterns. The most common is a “Z”pattern where the load is placed on oneside of the platform at one level andremoved from the opposite side atanother level. The second most commontraffic pattern is the 90-degree pattern

where the load is placed on one side ofthe platform at one level and unloaded tothe right or left (90 degrees) at theanother level. The last most common isthe “C” pattern where the load is placedon and removed from the same side ofthe platform at each level. It is alsopossible to have a combination of loadpatterns on multiple level or specialapplications. In some very specialapplications it may require 3-way or 4-way loading and unloading but these arerare and require special designedplatforms.

After the traffic pattern has beendetermined the VRC platform type canbe determined. See the followingapplication table.

VRC Design Z C 90 3 Way 4 Way

Straddle √ √ √

Cantilever √ √ √ √ √

Four Post √ √ √ √ √

Double Mast √ √ √

5.5 Loading and Unloading MethodsConsideration of the loading andunloading methods must be given whenspecifying a VRC as it may affect thedesign of the platform and the capacityof the unit. For instance, loading with ahand operated pallet jack may notrequire the same type of platformconstruction and unit capacity as loadingwith a powered pallet jack. Also,loading with a powered fork truck maynot be allowed at either level dependingon the VRC design specified, unless thespecification explicitly calls for forktruck roll-over capacity and it isdesignated at which elevation or level afork lift truck will be used. Note: Thisis true only in those applications wherethe fork truck must enter a platform inorder to place the load. If the fork truckmerely places the load on the platformwithout traveling onto the platformsurface, then a standard VRC shouldhandle the application, in which caserestraints, curbs or a barrier should beprovided to prevent fork truck entry ontothe platform. Consideration should also

be given to loads that may place aconcentrated load on the platform and/ormay not be on the platform’s load center.Most VRC manufacturers assumeuniform loading over the entire platformsurface. Wheeled carts or trucks andpallet jacks are prime examples of thistype of loading. When a VRC is used inan automated system with poweredconveyor mounted on the platform, thereactionary forces of the load startingand stopping should be anticipated andproper supports incorporated into theinstallation design. It should also benoted that turntables and pushers shouldbe given special consideration becauseof the abnormal forces they generate.When using hydraulically actuatedVRC’s in automated systems it may notbe advisable to use an upper level as the“Home Position” unless specialconsideration is given to the hydrauliccircuitry and/or automatic relevelingcontrol circuit design. Mechanical typeVRCs are not subject to down drift aswith hydraulic VRC’s and therefore,should be the first consideration forautomated system applications.

-5.6 Platform Guarding andAccessories

VRC platforms can be manufactured inan infinite number of configurations.The load to be transported, should beconsidered when determining the style,construction, height and type ofguarding, and accessories that areselected and specified. The minimumguarding requirement to meet the safetystandard is nominal 42” high handrailswith mid-rail and 4” high kick-plate onthe non-operating sides of the platformand a snap chain that is a minimum of39” high at its lowest point, mountedacross the loading or operating side(s).

5.6.1 Depending on the type of loadbeing conveyed fixed panels may besubstituted for handrails on the non-operating sides of the platform. Fixedpanels may be constructed of solid sheetor expanded metal panels may bepreferred. Typically, these are minimum48” high or higher depending on the typeof loads.

5.6.2 Gates and enclosures are requiredin accordance with ASME/ANSI B20.1(See section 10).

5.6.3 All gates, whether vertical acting,horizontal sliding, or swing gates, mustbe equipped with an interlock. (Seesection 2.20).

5.6.4 Drop bars or other devicesmounted to the platform that lower toprevent rolling loads from moving offthe platform during operation may berequired.

5.6.5 The safety of gravity or poweredroller conveyor used in conjunction with

VRC’s must be considered. Manyautomated systems, using poweredconveyor for loading/unloading, havedifferent guarding requirements. Consultyour VRC supplier.

5.7 Electrical Considerations andAreas of Use.

5.7.1 Operating conditions such asoutdoor, wash down area, airborne dust,oil mist, etc. must be considered. 5.7.2 Area activities such as a largevolume of fork truck or people trafficmay require special protectionconsiderations and/or key lock typecontrols for use only by authorizedpersonnel.

5.8 Operational Considerations 5.8.1 The controls may be constantpressure type where the operator musthold the operating button until the liftingor lowering cycle has been completed.

5.8.2 The controls may be momentarycontact call/send type, which onlyrequire the operator to press thedirectional button momentarily, allowingthe VRC to travel to the level theoperator has chosen, automatically andstop at that floor level by means of anelectrical switch or physical stop.

5.8.3 When loading a VRC with a forktruck, a ceiling mounted pull cord typeswitch may be desirable to activate theVRC and/or powered access gate.

5.8.4 In automated systems the controlsystem may be operated by a computer.

5.9 Power Unit and Drive Types

5.9.1 Hydraulically Driven Most VRCs fall into this class becauseof the overall lower cost to manufacturethis type of lifting system. The principalemployed by most VRC manufacturersfor this style drive is to use a singleacting hydraulic cylinder and multiplyits available stroke by means of amultiple cable or chain system. Theadvantage of this type of system is that itis economical and efficient but the travelheight is limited. Another economicalmethod incorporates a cylinder or ramacting directly on the VRC platform toraise and lower the load. The verticaltravel is a 1 to 1 ratio of cylinder stroketo travel.

Lowering of the platform is strictly afunction of gravity when the holdingvalve is opened allowing hydraulic fluidto drain back to the reservoir andlowering speed is controlled by a flowcontrol valve.

Hydraulic VRC’s are typically designedfor 2 level operations. They are notrecommended for applications withintermediate stops. Unless the unit isequipped with a positive stop or level-locking device the hydraulic controlsystem will not provide accuratestopping position repeatability underboth loaded and unloaded conditions.

5.9.2 Mechanically Driven This is the unit of choice for highertravel 2 level applications, 3 or morelevels of operation where intermediatestops are required, automated system

applications, and high speed or highcycle projects. This system utilizes anelectric brake motor with a gear reducer.The carriage is typically raised orlowered by means of a heavy-dutychain(s). Travel is controlled with anelectrical limit switch or similar deviceat each level. Stopping accuracy isnormally good in loaded and unloadedconditions

5.10 Sizing a Power UnitA VRC unit should be sized to easilyhandle its rated working capacity, thelifting speed, and its duty cycle. Includeweight of platform-mounted accessorieswhen specifying the rated capacity.

Particular attention should be given tohydraulic units operating in abnormallyhigh or low ambient temperatures as oiltemperature could affect performance.

5.11 Locating a Power Unit

Most manufacturers offer a standardremote mounted hydraulic power unit.The power units are typically designedto be positioned at either the top orbottom level. Reasons for a remotepower unit may be the area, which isclassified as non-hazardous, or theambient temperature may be bettersuited for hydraulic fluids, noise, to limitaccess, or simply for ease ofmaintenance.

A mechanical chain driven unit cannothave the power unit located remotely butthe electrical control panel may bemounted remotely within reasonableproximity of the lift thus reducing costsif the operating area is classified as ahazardous area.

6. Installation Considerations

6.1 Surface Mount

6.1.1 Floor anchors should be suitablefor the floor condition and thickness andmeet the manufacturer’s requirementsfor pull strength.

6.1.2 If loading is by other than acounter-balanced fork lift truck,conveyor or by hand, then a ramp maybe necessary. Typically there are twotypes of ramps; a fixed ramp mounted tothe floor on the loading side of theplatform or a hinge mounted to theplatform. If a hinged ramp is consideredthen the following should be given somethought.

The ramp will have to be raised andlowered for loading,

An electrical interlock should be used onthe ramp to ensure that it is in the raisedposition before operating the VRC.

If traveling through a hole at the upperlevel, it may have to be larger toaccommodate the ramp, and it mayinterfere with loading at the upper level.Note: The rule of thumb for length ofthe incline is 12” of length for each 1” ofrise.

For fork truck loading a curb on thelanding should be considered for theloading side in order to protect the VRCplatform from damage by the fork truck.

6.2 Pit Mount

6.2.1 VRC’s may be pit mounted withthe entire structure including the mast or

guide beams and the platform in the pit.However, straddle and four post designsallow pit mounting of the platform onlywith the mast or guide beams mountedto the floor surface and only the platformin the pit in the lowered position. Theadvantage of this style is the thickness ofthe floor will carry the load and willnormally not require additional footings.Consult your architect before makingthis assumption

6.2.2 If the entire unit including the mastand platform will reside in the pit, the pitshould be sized to accept thosecomponents with adequate clearancesprovided. The manufacturer willnormally supply a recommended pitdrawing. A normal platform runningclearance on the loading side(s) wouldbe 1" ”maximum and ½” minimum.

6.2.3 The pit floor should have properdrainage and sufficient strength.

6.2.4 The pit depth should be such that itwill allow shimming of the VRC tobring the platform top surface flush withthe floor.

6.3 Mast or Guide Beam Support

6.3.1 Most cantilever type VRCs willrequire the masts to be tied in to thebuilding structure at the upper leveland/or at intermediate levels to preventplatform sway caused by the reactionforces of loading and unloadingoperations at the upper levels.

6.3.2 Some double mast and four postconfigurations may be designed to becompletely free standing and may notrequire external support. Most VRCsrequire some support or stabilization

from the building structure; the VRCmanufacturer will provide therequirements for their particular VRCmodel.Note: In some areas seismic calculationsmay also be required prior to theinstallation of a VRC. Check your localand state requirements for criteriaregarding the extent of these calculationsand the qualifications required by theengineer who performs them.

6.4 Floor Opening and MezzaninesFloor hole sizes and edge of mezzanineclearance should be per manufacturer’srecommendations.

Where it is not possible to maintain themanufacturer’s recommended clearancesa throw-over plate may need to be addedto the edge of the VRC platform or ifpossible, build out the edge of thelanding to ensure safe loading andunloading. If large openings exist it maybe necessary to provide additionalguarding for personnel safety

7. Electrical Considerations

7.1 Adequate power must be available tothe location of the lift. Typically, thecustomer must provide the providingadequate power to within ten (10) feet ofthe lift.

7.2. A fused disconnect typically isrequired and is not typically provided asstandard equipment by the VRCmanufacturer.

7.3. Application specific conditions andhazards determine the electricalclassification or NEMA rating of the

area such as NEMA 1, NEMA 4 forwashdown, NEMA 7 or 9 for hazardousenvironments, etc.

8. Wiring Considerations

8.1 Many parts of the VRC are prewiredby the manufacturer, but there can beconsiderable field wiring.

8.2 All wiring must be accordance withThe National Electric Code and/or anyapplicable local code requirements.

9. Power Unit Considerations

9.1 Hydraulic power units can bemounted on or near the mast. Typically,they should be within thirty (30) feet ofthe VRC. Hydraulic units typicallydevelop little heat under normaloperating conditions and can be placedin confined areas such as understairwells provided they are accessiblefor maintenance.

9.2 Mechanical power units or drivesare typically mounted at the top of themast or guide beams. Since these unitsrequire little service catwalks and/ormaintenance ladders are not required.

10. Safety Gate and EnclosureConsiderations

10.1 Basic Requirements

10.1.1 ASME/ANSI B20.1 requires 96”high enclosures at each floor level withthe exception of the top floor or landingwhich in some cases may be permissibleto use 42” high handrails as a portion ofthe guarding.

Enclosures may be fabricated fromwoven wire, expanded metal, sheet

metal, studded wall (wood or steel), orcement block. Wire or metal mesh musthave openings small enough to reject a2” ball. All enclosures must be able towithstand 100 pounds of force in anydirection.

Types of loads and internal companysafety standards may determine the typeand height of enclosures to be used. Forexample, a VRC carrying small looseboxes would be considered safer if itwere enclosed the full height betweenfloor levels and to a height of 84” abovethe upper floor level service.

The location of a VRC will alsodetermine the type and size of anenclosure. It may be advantageous tolocate the VRC along side a wall or in acorner thus reducing the size of theenclosure required to safely enclose theVRC.

The positioning of the enclosure inrelationship to the VRC is important.The distance between the inside of theenclosure and the extremities of theVRC normally should be kept to aminimum to reduce the possibility of aperson from being positioned betweenthe enclosure and the VRC.”

10.2 Safety Gate TypesMany manufacturers offer special gatesnot listed. Consult the VRCmanufacturer. Note: Gates do not takethe place of fire doors where required.

10.2.1 Single Swing Type Gate. Thistype of gate hinges on one sideand latches on the other, may beeither right or left-hand swing.Probably the most common typein use, but the clear openingwidth is limited normally to

approximately 60” to 72”maximum and requires clearspace in front of the lift to swing

open. Typical swing gate heightis 84” but may be raised orlowered to accommodate loadheight requirements or to allowsupport between adjacentenclosure panels or walls.

10.2.2 Bi-parting, Double Swing TypeGates. This type of gate hingeson each side and latches in thecenter. This style of gate may beused for openings greater than60” but usually not exceeding120” in width.

10.2.3 Single Panel, Counter-balancedVertical Rising Gate Assembly. Thistype of gate closes to the floor and opensin the upward direction. This style ofgate can be constructed to handle gateopenings up to 16’ wide. Though theyare normally either 72” or 96” high theycan be made higher, however, the drawback being vertical rising gates need avertical guide track which will be at leasttwice the height of the gate panel. Thisstyle gate may not be feasible in aninstallation where loading is on the sameside two consecutive floors.

10.2.4 Double Panel, Counter-balanced, Vertical Rising GateAssembly. This type of gate is the sameas the single panel, counter-balancedvertical rising gate assembly above inoperation and use except the two (2)panels telescope from a nested positionwhich only requires about 75% as muchoverall height.

10.2.5 Horizontal Sliding Type GateAssembly. This style gate operates inthe same matter as a vertical rising gate

assembly except it functions in thehorizontal direction and requiresconsiderable storage room on one sidewhen open. Another disadvantage ofthis type of gate is that it requires anoverhead track above the gate opening.

10.2.6 Roll-up Type Door Assembly.This style gate can be anything from anindustrial type roll-up steel door to self-storage facility type door. This stylegate has an advantage in that the gate

itself does not require a lot of space.Some disadvantages are that it is slow inoperation, may require considerablemaintenance, and it is mounted over thegate opening and may limit the load

height. It may be of the manual orpowered variety.

All of the above gates must be equippedwith an electro-mechanical interlocksystem to meet the code requirement.The purpose is to discourage peoplefrom riding the carrier or carriage and tohelp provide a guarded opening at anylanding. The locking component of theinterlock system is designed to lock thegate or door in the closed positionwhenever the lift carrier or carriage isnot present at that particular opening.The gate status component is intended toprevent operation of the VRC unless allgates are closed.

10.3 Gate Interlocks - General

Regardless of the fate or door type, allaccess gates must be equipped with anelectromechanical interlock system tomeet the code requirement and toprovide a safe operating environment.The purpose of the interlocking systemis to help prevent the occurrence of anunintentional or unguarded gate/doorfrom opening at a landing level when thecarrier or carriage is not present at thatlevel and to help prevent people frombeing able to ride on the VRC carrier orcarriage.

There are two (2) primary elementscommon to any code compliantinterlocking system; a mechanicallocking component and a status-sensingcomponent. The locking component canbe either electrically or mechanicallyactuated and is designed to mechanicallylock the gate or door in the closedposition whenever the lift carrier orcarriage is not present at that particularlanding. The gate status switchcomponent is intended to provide an

electrical signal to the control panel thatwill prevent the operation of the VRCunless all gates are fully closed.

10.3.1 Mechanically ActuatedInterlocks

Mechanical interlocks are devices thatnormally integrate both the locking andstatus sensing components of theinterlock system in a single housing.This type of interlock provides amechanical actuation of a mechanicallocking device and is typically mountedto a permanent structure just inside thegate and adjacent to the landing positionof the carrier or carriage. This interlockreceives a striker plate which is mountedto the fate/door panel from the top orside depending on the type of gate/door.This striker plate automatically capturedmechanically when the lift leaves thelanding and automatically andmechanically opens or closes theelectrical circuit to the motor starter withits presence or absence.

There are several advantages to this typeof interlock system; 1) it is both a gatesensing and gate locking device, 2) it isdifficult to tamper with or override, 3) itprovides simple, durable, and reliableservice in dirty or dusty environments,and 4) it requires close proximity to thelift carrier or carriage to be actuated by acam on the lift which inherently createsless space between the gate/door and thefor a person to stand while the gate isclosed. A disadvantage is its bulky sizewhich limits its use in applicationscalling for very tight running clearancessuch as shaft installations.

10.3.2 Electrically ActuatedInterlocks

Electrically actuated or solenoidinterlocks are devices that normallyprovide only the locking element of theinterlock system. A separate se ofelectrical switches typically must beinstalled to provide status sensing of thegates/door. This type of interlockprovides an electrical actuation of amechanical locking device and istypically mounted to the gate post frameor header. The mechanicaldevice/plunger is installed in such a wayas to capture the gate(s)/doors(s) whenclosed and actuates immediately afterthe lift carrier or carriage leaves thelanding. The separate gate statusswitches are installed in the samevicinity as the solenoid interlock andopen or close the electrical circuit to themotor starter with the gate/door’s statusof being either open or closed.

The advantages to this type of interlocksystem are: 1) it is easier to position andinstall, 2) it is typically less expensive topurchase, and 3) it is small, compact andfits well into cramped environments withtight running clearances such as shaftways. Disadvantages to the solenoidinterlock system are: 1) its sensitivedesign which makes it less suitable fordirty or dusty environments, 2) itrequires the addition of gate statusswitches to perform to code, and 3) theinterlock and status switches are moreeasily tampered with or overriddenbecause they are typically not wellguarded and installed on gate/frameswhich are more easily accessible to non-maintenance personnel.

11 Labeling

11.1 Minimum Recommended LabelsThe following illustrations describeminimum recommended labels and theirlocations for all VRC’s. See figure 11for locations of the signs.

11.1.2 It is recommended that five (5)different signs be used in variouslocations on the VRC as illustratedbelow.

11.1.3 Signs #1, #3, #4, and #5 arewarning signs and therefore are orange.Sign #2 is a danger sign and therefore, isred.

11.1.4 Sign #1 should be approximately7” x 8-5/8” and reads: Warning— onlytrained persons shall be permitted tooperate or maintain this equipment.Improper operation or maintenance maycause serious injury or death. Reviewoperations manual before use.

11.1.5 Sign #2 should be approximately2-1/2” x 5-1/4” and reads: Danger —This door must be closed and lockedunless carrier is present.

Door interlock must be operational. Itprevents door from being opened whencarrier is not present.

Door restricts personnel from fallinginto opening or being struck by movingparts resulting in serious injury ordeath.

11.1.6 Sign #3 should be a sticker. Itshould be approximately 7/8” x 2-1/8”

and is designed to fit onto the pushbutton stations. It reads: Warning: Donot allow riders.

11.1.7 Sign #4 is should beapproximately 3-1/2” x 10” and reads:Warning: No Riders.

11.1.8 Sign #5 is 7-3/4” x 12-7/8” andreads: Do not ride on this equipment.Personnel safeguards are not providedand serious injury or death could result.

This sign also has a “no personnel”symbol on it.

12. Maintenance Considerations

12.1 General MaintenanceThe following are general guidelines.Always refer to manufacturer’s Ownersmanual.

12.1.1 Maintenance, such as lubricationand adjustment, shall be performed byqualified and trained personnel.

12.1.2 Lack of maintenance may cause ahazardous condition, the user shallestablish a maintenance program toensure that VRC components aremaintained in a condition that does notconstitute a hazard to personnel (seeowner’s manual).

12.1.3 No maintenance, or lubrication,shall be performed when the VRC is inoperation. Most VRC’s are servicedwith the carrier or carriage lowered.Consult manufacturer’s serviceinstructions.

12.1.4 When the VRC is stopped formaintenance or repair purposes, the mainpower shall be locked or tagged out inaccordance with a formalized proceduredesigned to protect all persons or groupsinvolved with the VRC against anunexpected restart.

12.1.5 All safety devices and guardsshall be replaced before startingequipment for normal operation.

12.1.6 Routine inspection and correctivemaintenance measures shall beconducted to ensure that all guards andsafety features are in place and functionproperly.

12.2 Hydraulically Actuated VRC

12.2.1 Check hydraulic fluid level andfluid contamination. 12.2.2 Check hydraulic fitting leakage. 12.2.3 Check hydraulic cylinder seals

12.3 Mechanically Actuated VRC 12.3.1 Check fluid levels in gearboxes 12.3.2 Grease pillow blocks permanufacturer’s instructions. 12.3.3 Inspect motor brake assembly,mechanical connections, such assprockets to drive shafts, inc. 12.4 VRC Lift System 12.4.1 VRC with lifting chains, checkfor chain stretch with chain gauge, checkchain connections, and lubricate permanufacturer’s instructions. 12.4.2 VRC with cable lifting system,check for stretched or frayed cable(s)and replace. Check cable attachment,and inspect and lubricate cable sheavesper manufacturer’s instructions. Figure 1112.4.3 For a VRC with screw jack typelift system follow manufacturer’sinstructions for care and maintenance. 12.5 VRC Guide System 12.5.1 Check with VRC manufacturer,but in general the guide wheels, rollers,or slide mechanisms may need to belubricated if not equipped with sealedbearings and the guide rails may requireperiodic greasing.

12.5.2 Inspect rails for abnormal wear ordeformation. 12.6 VRC Safety Devices

12.6.1 All VRCs on which the carrier orcarriage is suspended must be equippedwith a falling platform safety device(s).These devices may require periodictesting and lubrication depending on themanufacturer. Direct acting hydraulicram or cylinder supported carriers orcarriages do not require a fallingplatform safety device and should no besubject to any applicable drop testrequirements. The manufacturer’sinstructions for these devices should befollowed exactly. 12.6.2 On hydraulic actuated VRCs, arelief valve is provided in the hydraulicpower unit as a safety device to preventoverload and is factory set prior toshipment. Any adjustment to this deviceshould only be done with factoryapproval and/or supervision. 12.6.3 On mechanical VRCs, they maybe equipped with either slack cable/slackchain safety shut off switches and/orcable/chain over-tension shut off switch,all of which will require periodic checksto make sure they are functional. 12.6.4 Other safety devices that mayrequire maintenance and checking if theVRC is so equipped, are any removableguard interlocks, gate electrical-mechanical interlocks, and over-travellimit switches. There may be otherdevices not mentioned. Check with themanufacturer of the VRC that you areconsidering.

13 Operation Considerations

13.1 Only a trained person shall bepermitted to operate the VRC. Trainingshall include instruction in operationunder normal conditions and emergencysituations.

13.2 No person shall ride on a VRC.

13.3 The VRC shall be used to transportonly loads it is designed to handle safely.

13.4 The area around loading andunloading points shall be kept clear ofobstructions that could endangerpersonnel or interfere with properoperation of the VRC.

13.5 Emergency stop buttons shall bekept free of obstructions to permit readyaccess.

13.6 Personnel working on or near theVRC shall be instructed as to thelocation and operation of the Emergencystop buttons.

13.7 Under no circumstances shall thelimit switches, operating controls orsafety devices of the VRC be altered ormodified or their functionality defeatedas such alterations would endangerpersonnel.

14 Potential Applicable Codes

ANSI B20.1 Safety Standard forConveyors and Related Equipment

Fire Underwriters

National Electric Code

ANSI Z535.4 Product Safety Sign andLabel

15 Start-up Testing

15.1 Close all gates and doors.

15.2 Run the empty VRC carrier orcarriage to each level.

15.3 Check that gates at all levels willnot open if the lift is not present.

15.4 Check to ensure the lift will notoperate if any gate is open.

15.5 Place a capacity load on the carrieror carriage and run the carrier or carriageto all levels. The carrier or carriageshould stop at the proper elevationloaded and unloaded.

15.6 Allow the carrier or carriage toremain at the top level for 4 hours.Platform should not drift or leak oil.

15.7 Check to ensure the lift operates atthe rated speed.

15.8 The VRC should function smoothlyand relatively quietly. If the VRC doesnot function as stated in the ownersmanual or does not pass these tests,consult the manufacturer before puttingthe lift into service.

15.9 Check that each emergency stopbutton will stop the moving carrier orcarriage. The carrier or carriage shouldnot resume movement when theemergency stop button is returned to itsnormal position.