This Safety and Health Information Bulletin is

not a standard or regulation, and it creates no

new legal obligations. The Bulletin is advisory in

nature, informational in content, and is intended

to assist employers in providing a safe and

healthful workplace. The Occupational Safety

and Health Act requires employers to comply

with hazard-specific safety and health standards.

In addition, pursuant to Section 5(a)(1), the

General Duty Clause of the Act, employers must

provide their employees with a workplace free

from recognized hazards likely to cause death or

serious physical harm. Employers can be cited

for violating the General Duty Clause if there is a

recognized hazard and they do not take reasonable steps to prevent or abate the hazard. However, failure to implement any recommendations

in this Safety and Health Information Bulletin is

not, in itself, a violation of the General Duty

Clause. Citations can only be based on standards, regulations, and the General Duty Clause.

U. S. Department of Labor

Occupational Safety and Health Administration

Directorate of Science, Technology & Medicine

Office of Science and Technology Assessment

SHIB 08-16-2004

Safety and Health Information Bulletin

Hazards of Improper Elevator Controller Wiring

Preface

An employee was fatally injured when the

elevator he was entering continued to move while the

elevator doors were open. An investigation revealed

that the interlock, which would have prevented

movement of the elevator car with the doors in the

open position, had been bypassed due to improper

wiring. This incident highlights the importance of

elevator maintenance and repair adhering to

manufacturer design codes and applicable industry

safety procedures and standards.

Purpose

The purpose of this Safety and Health

Information Bulletin (SHIB) is to:

• identify potential hazards of an

incorrectly wired elevator controller;

• identify consensus standards applicable

to elevators;

• provide information to employers

regarding the importance of complying

with consensus safety and maintenance

standards for elevators; and

• notify employers of required testing and

verification of proper elevator operation

before releasing elevators into service.

Background

The Occupational Safety and Health

Administration (OSHA) Houston South Area Office

investigated a fatality in Houston, Texas that involved

improper elevator wiring. As a result of improper

wiring of the elevator’s controller, the hoistway door

interlock circuit was bypassed, permitting the elevator

car to travel at full-speed with the doors open. This

condition resulted in fatal injuries to an employee

entering the elevator while the elevator was moving.

Accident Description

Mechanics employed by a contracted

maintenance company were assigned to install a new

generator for an elevator at a hospital. In addition to

installing the generator, the mechanics also reportedly

found and repaired a short circuit in the system. The

mechanics then tested the elevator and returned it to

service. The fatal accident occurred about 25 hours

later. There were no reports of malfunctioning
2

between the time the elevator was returned to service

and the time of the fatal accident.

The victim was trying to board the elevator.

As he approached the elevator, the elevator doors

were closing, and he extended his arms in an attempt

to hold the doors open. The victim then put his leg up

and tried to get into the elevator, which was moving

up. The victim became pinned between the elevator

doors. He was caught between the elevator car and

the hoistway as the elevator continued to move up,

and he died immediately.

The investigation of this accident was

comprehensive and systematic. The investigation

concluded that at some point wiring was removed

and subsequently reattached incorrectly to an

adjacent electrical terminal of the elevator car

controller (see Figure 1), bypassing the hoistway-door

interlocks and resulting in the elevator’s ability to

move with the doors in an open position. A review of

the elevator’s wiring diagram substantiated the

improper wiring.

Other Information

While there are no specific OSHA standards

addressing the pattern of electrical wiring for elevator

control panels, the Occupational Safety and Health

Act requires employers to provide a workplace that is

“free from recognized hazards that are causing or are

likely to cause death or serious physical harm to his

employees.” To this end, employers need to take

reasonable steps to assure that employees who

perform work on elevators are adequately trained in,

and knowledgeable of, elevator design specifications

and proper maintenance procedures. Further,

equipment must be maintained in accordance with

manufacturer design specifications and operating

procedures.

State governments also regulate the

installation, maintenance, repair, and operation of

elevators. Typically, the state Department of Labor

and Industry or similar state agency oversees elevator

installation and operation. Many of these agencies

require compliance with industry standards and

guidance for elevators, as discussed in the following

paragraph. A directory of state elevator code

authorities can be accessed through http://

www.neii.org/. In some cases, local authorities

regulate the installation, repair, maintenance, and

operation of elevators; and employers need to ensure

compliance with these local requirements.

The safe work procedures and equipment

necessary to assure the safety of elevator passengers

and maintenance workers have been developed over

time by the elevator industry. Industry standards and

guidance documents related to this subject are

provided by the American Society of Mechanical

Engineers (ASME), the National Elevator

Manufacturing Industry, Inc. (NEMI, also known as

the National Elevator Industry, Inc. (NEII)), and the

National Elevator Industry Educational Program

(NEIEP).

Specific safety procedures and equipment that are

necessary to prevent incidents similar to the fatality in

Houston are included in the following:

Figure 1: Controller Panel 

Note two wires connected to Terminal 

C105 and no wires connected to 

Terminal C103. 

C103

C105
3

Conclusions

The Houston, Texas accident illustrates the

importance of assuring that elevator components are

properly wired and procedures followed to assure that

the elevator will operate properly before it is returned

to service. Elevator maintenance companies and

employers should take steps to ensure the integrity of

elevator wiring performed during maintenance

activities and adhere to the wiring diagrams specified

by the elevator manufacturer. In addition, employees

performing maintenance and repair work on elevators

must be trained in, and knowledgeable of, applicable

standards, including proper testing and verification

mechanisms required before returning elevators to

service.

Recommendations

To ensure the safe operation of elevators and

the protection of employees, employers need to

assure that employees who install and maintain

elevators are adequately trained and knowledgeable

about proper installation, wiring, and maintenance

procedures. The following guidelines will help reduce

the risk of employee injury from malfunctioning

elevators:

• Integrity of electrical wiring.

Maintenance personnel should review

the controller and advancer wiring.

Wiring diagrams should be kept on

site and reviewed to ensure that the

controller and advancer panel wiring

is correct, to make certain the door

interlocks are operating properly, and

to prevent operation of the elevator

driving mechanism when either the

hoistway door or elevator cab door is

not properly closed.

• Employee training. Maintenance

technicians, elevator inspectors, safety

compliance personnel and consultation

personnel should be familiar with the

consensus safety standards applicable to

elevators. Employers need to ensure that

their personnel are knowledgeable of the

safe procedures to positively control

hazards and the recommended fail-safe

measures to “test and verify” proper

operation of an elevator following

maintenance activities and prior to

releasing an elevator into service.

• Adherence to industry standards. The

referenced industry standards address

proper elevator maintenance and

post-maintenance procedures. Service

personnel need to be knowledgeable of

proper procedures, and employers need

to take reasonable steps to ensure that

their personnel adhere to these

procedures. Employers should implement

effective maintenance control programs

for elevator systems and ensure that

methods are used to detect and correct

any defects affecting safe operation of an

elevator system following maintenance

activities and before the elevator is

returned to service.

ASME A17.1 - Safety Code for Elevators and

Escalators, 2000

ASME A17.2 – Guide for Inspection of Elevator,

Escalators, and Moving Walks, 2001,

(consolidation of A 17.2.1, A17.2.2, and A

17.2.3)

ASME A17.3 – Safety Code For Existing

Elevators and Escalators, 2002

NEII - Elevator Industry Field Employees

Safety Handbook – 2000
References

1. American Society of Mechanical Engineers

(ASME). Safety Code for Elevators and

Escalators, 2000. ASME A17.1.

2. American Society of Mechanical Engineers

(ASME). Guide for Inspection of Elevator,

Escalators, and Moving Walks, 2001

(consolidation of A 17.2.1, A17.2.2, and A

17.2.3). ASME A17.2.

3. American Society of Mechanical Engineers

(ASME). Safety Code for Existing

Elevators and Escalators, 2002. ASME

A17.3

4. National Elevator Industry, Inc. (NEII).

Elevator Industry Field Employees Safety

Handbook – 2000. http://www.neii.org/

Links/Citations to the websites listed above are offered for the

reader’s convenience. Since OSHA does not control the

information contained in the websites, OSHA cannot assure the

accuracy, relevance, timeliness, or completeness of all of this

information. Moreover, providing links/citations to such

websites does not constitute an endorsement of the websites, or

their content, nor does it suggest that these websites are the

exclusive or most useful sources of relevant information.