JLG LSS Scissors Operator Manual

Operation & Safety, Service &

Maintenance & Illustrated Parts

Manual Supplement

JLG

LOAD

SENSING

SYSTEM

Vertical Lift Products

P/N

3124289

July 29, 2013

INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

INTRODUCTION

GENERAL

This section contains the general safety precautions
which must be observed during maintenance of the aerial
platform. It is of utmost importance that maintenance per­sonnel pay strict attention to these warnings and precau­tions to avoid possible injury to themselves or others, or
damage to the equipment. A maintenance program must
be followed to ensure that the machine is safe to operate.

MODIFICATION OF THE MACHINE WITHOUT CERTIFICATION BY
A RESPONSIBLE AUTHORITY THAT THE MACHINE IS AT LEAST
AS SAFE AS ORIGINALLY MANUFACTURED, IS A SAFETY VIOLA­TION.

The specific precautions to be observed during mainte­nance are inserted at the appropriate point in the manual.
These precautions are, for the most part, those that apply
when servicing hydraulic and larger machine component
parts.

Your safety, and that of others, is the first consideration
when engaging in the maintenance of equipment. Always
be conscious of weight. Never attempt to move heavy
parts without the aid of a mechanical device. Do not allow
heavy objects to rest in an unstable position. When raising
a portion of the equipment, ensure that adequate support
is provided.

SINCE THE MACHINE MANUFACTURER HAS NO DIRECT CON­TROL OVER THE FIELD INSPECTION AND MAINTENANCE,
SAFETY IN THIS AREA IS THE RESPONSIBILITY OF THE OWNER/
OPERATOR.

MAINTENANCE

FAILURE TO COMPLY WITH SAFETY PRECAUTIONS LISTED IN
THIS SECTION MAY RESULT IN MACHINE DAMAGE, PERSONNEL
INJURY OR DEATH AND IS A SAFETY VIOLATION.

• REMOVE ALL RINGS, WATCHES AND JEWELRY
WHEN PERFORMING ANY MAINTENANCE.

• DO NOT WEAR LONG HAIR UNRESTRAINED, OR
LOOSE-FITTING CLOTHING AND NECKTIES WHICH
ARE APT TO BECOME CAUGHT ON OR ENTANGLED
IN EQUIPMENT.

• OBSERVE AND OBEY ALL WARNINGS AND CAU­TIONS ON MACHINE AND IN SERVICE MANUAL.

• KEEP OIL, GREASE, WATER, ETC. WIPED FROM
STANDING SURFACES AND HAND HOLDS.

• NEVER WORK UNDER AN ELEVATED PLATFORM
UNTIL PLATFORM HAS BEEN SAFELY RESTRAINED
FROM ANY MOVEMENT BY BLOCKING OR OVER­HEAD SLING.

• BEFORE MAKING ADJUSTMENTS, LUBRICATING OR
PERFORMING ANY OTHER MAINTENANCE, SHUT
OFF ALL POWER CONTROLS.

• BATTERY SHOULD ALWAYS BE DISCONNECTED­DURING REPLACEMENT OF ELECTRICAL COMPO­NENTS.

• KEEP ALL SUPPORT EQUIPMENT AND ATTACH­MENTS STOWED IN THEIR PROPER PLACE.

• USE ONLY APPROVED, NONFLAMMABLE CLEANING
SOLVENTS.

HYDRAULIC SYSTEM SAFETY

It should be noted that the machines hydraulic systems
operate at extremely high, potentially dangerous pres­sures. Every effort should be made to relieve any system
pressure prior to disconnecting or removing any portion of
the system.

3124289 – JLG Lift – A

INTRODUCTION

July 1, 2003 - Original issue of Manual
March 1, 2004 - Revised
May 17, 2005 - Revised
July 15, 2006 - Revised
March 31, 2011 - Revised
March 1, 2012 - Revised
August 11, 2012 - Revised
January 23, 2013 - Revised
July 29, 2013 - Revised

REVISION LOG

B – JLG Lift – 3124289

TABLE OF CONTENTS

TABLE OF CONTENTS

SUBJECT - SECTION, PARAGRAPH PAGE NO.

SECTION - INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A

HYDRAULIC SYSTEM SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A

MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A

EFFECTIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B

SECTION 1 - OPERATION

1.1 INTRODUCTION & OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

Overload Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Overload Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

SECTION 2 - SERVICE PROCEDURES - LOAD SENSING SYSTEM

2.1 LOAD SENSING SYSTEM (LSS) DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

Manually Propelled Vertical Lift - Overload Detection (Manually Propelled Lifts). . . . . . . . . . 2-1

Drivable Vertical Lift - Overload Detection (Drivable Vertical Lifts) . . . . . . . . . . . . . . . . . . . . .2-1

2.2 LSS - SETUP AND ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

Procedure Overview (All Vertical Lifts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

Adjustment Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

Adjustment Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

LSS Operation Function Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

2.3 COMPONENT REMOVAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

LSS Panel Component Installation - (Manually Propelled Lifts Only). . . . . . . . . . . . . . . . . . .2-5

LSS Indicators (Drivable Vertical Lifts Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

LSS Platform Mount Attach Arms to Mast Header Installation (All Lifts). . . . . . . . . . . . . . . . . 2-6

LSS Limit Switch Installation (All Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

LSS Platform Mount, Coil Spring to Mast Crossmember Installation (All Lifts) . . . . . . . . . . . 2-6

2.4 LSS TIMING MODULE - (MANUALLY PROPELLED LIFTS ONLY) . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2.5 GROUND CONTROL MODULE (DRIVABLE VERTICAL LIFTS ONLY) . . . . . . . . . . . . . . . . . . . . . . 2-8

Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

LCD Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.6 PLATFORM CONTROL CONSOLE (DRIVABLE VERTICAL LIFTS ONLY) . . . . . . . . . . . . . . . . . . .2-8

2.7 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

SECTION 3 - ILLUSTRATED PARTS

TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3124289 – JLG Lift – i

TABLE OF CONTENTS

LIST OF FIGURES

FIGURE NO. TITLE PAGE NO.

1-1. L.S.S. Indicator Panel Location - (Manually Propelled Vertical Lifts) . . . . . . . . . . . . . . . . . . . . . . .1-1

1-2. Load Sensing System - Indicators (Drivable Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

2-1. Load Sensing System - Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2-2. Load Sensing System - Indicators (Drivable Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2-3. Platform Console LED Indicators (Drivable Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2-4. LSS Component Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2-5. LSS Wiring Diagram - (For Manually Propelled Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

2-6. LSS Wiring Diagram - (For Drivable Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

3-1. Platform Support & Load Sensing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

LIST OF TABLES

TABLE NO. TITLE PAGE NO.

2-1 Test Weight Requirement Per Machine Model. (Percent of Maximum Platform Capacity) . . . . . .2-3

2-2 LSS Timing Module (J1 - Black Connector) Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2-3 Ground Control Module Programming - Drivable Lifts ONLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-4 Troubleshooting - Machine Indicates (Possible False) Platform Overload Condition -

(Manually Propelled Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-5 Troubleshooting - Machine Indicates (Possible False) Platform Overload Condition -

(Drivable Vertical Lifts). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

ii – JLG Lift – 3124289

SECTION 1. OPERATION

–+

NOTE: This manual is intended as a supplement to the indi-

vidual machine’s Operators and Safety Manual, Ser­vice and Maintenance Manual and Illustrated Parts
Manual.

1.1 INTRODUCTION & OPERATION

NOTE: It is the responsibility of the owner/user/operator/les-

sor/lessee to read & understand this manual and the
machine Operators & Safety Manual and to prevent
overloading the platform. Do not operate a machine
with a disconnected or inoperative Load Sensing
System.

The JLG Load Sensing System (LSS) for Vertical Mast
Products is designed to detect when actual platform load
exceeds the machine’s Maximum Rated Load Capacity.

Overload Indication

When the Maximum Rated Load Capacity is exceeded the
following will occur:

SECTION 1 - OPERATION

NOTE: There is a three (3) second delay between detection

and overload indication.

MANUALLY PROPELLED LIFTS (See Figure 1-1.)

1. The LSS Warning Alarm and Lamp will activate 1
second ON, and 2 seconds OFF.

2. The platform lift up/down function will be disabled to
prevent movement of the overloaded platform.

DRIVABLE LIFTS (See Figure 1-2.)

1. The LSS Warning Alarm and Lamp will activate 5
seconds ON, and 2 seconds OFF. Also a 9 LED
code will flash on the platform control console (see
below), and the Ground Control Module LCD screen
will indicate a platform overload condition.

2. The platform lift up/down and driving functions will
be disabled to prevent movement of the overloaded
platform.

NOTE: Ground control functions may be disabled depen-

dent on Ground Control Module programming.

Figure 1-1. L.S.S. Indicator Panel Location -

(Manually Propelled Vertical Lifts)

1. Platform Control Panel 3. LSS Warning Alarm

2. L.S.S. Indicator Panel 4. LSS Warning Lamp

Platform Console LED Indicators

(Drivable Vertical Lifts)

1. The platform console LED bar will flash 9 (Nine) LEDs
to indicate a Platform Overload condition.

3124289 – JLG Lift – 1-1

Figure 1-2. Load Sensing System - Indicators

(Drivable Vertical Lifts)

1. Ground Control Module 3. LSS Warning Lamp

2. LSS Warning Decal 4. LSS Warning Alarm

SECTION 1 - OPERATION

Overload Recovery

Further movement of the platform is permitted by remov­ing excess platform load until the LSS resets. This may
require removing load until a load less than rated capacity
is achieved.

NOTE: There is a 5 second delay between overload reset

and machine function activation.

THE LOAD SENSING SYSTEM WILL REQUIRE ADJUSTMENT
WHEN ONE OR MORE OF THE FOLLOWING CONDITIONS
OCCUR:

• Load Sensing System initial installation

• LSS component is disassembled or replaced

THE LOAD SENSING SYSTEM REQUIRES PERIODIC FUNCTION
VERIFICATION NOT TO EXCEED 6 MONTHS FROM PREVIOUS
VERIFICATION.

1-2 – JLG Lift – 3124289

SECTION 2 - SERVICE PROCEDURES - LOAD SENSING SYSTEM

32491011781

6

5

SECTION 2. SERVICE PROCEDURES - LOAD SENSING SYSTEM

2.1 LOAD SENSING SYSTEM (LSS) DESCRIPTION

The LSS system for Vertical Mast model machines con­sists of a floating platform mount weldment (rails)
attached to the sides of the mast header section, transfer­ring the platform load to a load bearing crossmember. The
platform mount load bearing crossmember is supported
by coil springs mounted between the platform crossmem­ber and a crossmember attached to the mast header sec­tion. Also attached to the platform mount weldment (rails)
is an adjustable actuator. The actuator, when adjusted
properly, trips the LSS limit switch mounted on the mast
crossmember when the platform is overloaded.

While the mechanical portion of the LSS system operates
the same for both the manually propelled and drivable
vertical lifts, the limit switch circuit (electrical) is monitored
differently as described following.

Manually Propelled Vertical Lift - Overload Detection

(See Figure 2-1.)

The limit switch circuit on the manually propelled lifts is
monitored by an LSS Timing Module which disables the
platform lift up/lift down function, sounds an audible warn­ing alarm and activates a flashing warning lamp when a
platform overload condition is detected. The LSS Timing
Module is mounted behind the LSS Indicator Panel
located behind the platform railing.

Drivable Vertical Lift - Overload Detection

(See Figure 2-1., Figure 2-2. and Figure 2-3.)

The limit switch circuit on the drivable lift is monitored by
the Ground Control Module (GCM) which controls all
machine functions and is mounted inside the machine’s
rear covers. Like the LSS Timing Module on the manually
propelled lifts, on overload detection the GCM on the driv­able lift disables the platform lift up/lift down function, in
addition the drive function is also disabled. Indicators of
an overload condition are; an audible warning alarm;
flashing warning lamp; 9 LEDs flash on the platform con­trol console and GCM LCD screen will flash "Platform
Overload". On the drivable lift, the audible warning alarm
and flashing warning lamp are located on the machine’s
left rear cover. (See Figure 2-2.)

On initial LSS installation or GCM replacement, the GCM
must be programmed to detect the LSS system in order to
function properly. See Section 2.5, "Ground Control Mod­ule" in this manual for instructions on GCM - LSS detec­tion programming.

Figure 2-1. Load Sensing System - Components.

1. LSS Timing Module (a) 7. Crossmember Stops

2. LSS Indicator Panel (a) 8. LSS Overload Actuator

3. LSS Warning Lamp (b) 9. LSS Limit Switch

4. LSS Warning Alarm (b) 10. Mast Header

5. Platform Mount (c) 11. LSS Arm Linkage

6. Coil Spring Assemblies

Note: (a) Manually propelled lifts only.

(b) Relocated on drivable lifts (See Figure 2-2.)
(c) Shown cut-away for illustrative purposes only.

3124289 – JLG Lift – 2-1