[Code of Federal Regulations]
[Title 29, Volume 8]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 29CFR1926.406]

[Page 259-260]
 
                             TITLE 29--LABOR
 
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT 
                                OF LABOR
 
PART 1926_SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION--Table of Contents
 
                          Subpart K_Electrical
 
Sec. 1926.406  Specific purpose equipment and installations.

    (a) Cranes and hoists. This paragraph applies to the installation of 
electric equipment and wiring used in connection with cranes, monorail 
hoists, hoists, and all runways.
    (1) Disconnecting means--(i) Runway conductor disconnecting means. A 
readily accessible disconnecting means shall be provided between the 
runway contact conductors and the power supply.
    (ii) Disconnecting means for cranes and monorail hoists. A 
disconnecting means, capable of being locked in the open position, shall 
be provided in the leads from the runway contact conductors or other 
power supply on any crane or monorail hoist.
    (A) If this additional disconnecting means is not readily accessible 
from the crane or monorail hoist operating station, means shall be 
provided at the operating station to open the power circuit to all 
motors of the crane or monorail hoist.
    (B) The additional disconnect may be omitted if a monorail hoist or 
hand-propelled crane bridge installation meets all of the following:
    (1) The unit is floor controlled;
    (2) The unit is within view of the power supply disconnecting means; 
and
    (3) No fixed work platform has been provided for servicing the unit.
    (2) Control. A limit switch or other device shall be provided to 
prevent the load block from passing the safe upper limit of travel of 
any hoisting mechanism.
    (3) Clearance. The dimension of the working space in the direction 
of access to live parts which may require examination, adjustment, 
servicing, or maintenance while alive shall be a minimum of 2 feet 6 
inches (762 mm). Where controls are enclosed in cabinets, the door(s) 
shall open at least 90 degrees or be removable, or the installation 
shall provide equivalent access.
    (4) Grounding. All exposed metal parts of cranes, monorail hoists, 
hoists and accessories including pendant controls shall be metallically 
joined together into a continuous electrical conductor so that the 
entire crane or hoist will be grounded in accordance with Sec. 
1926.404(f). Moving parts, other than removable accessories or 
attachments, having metal-to-metal bearing surfaces shall be considered 
to be electrically connected to each other through the bearing surfaces 
for grounding purposes. The trolley frame and bridge frame shall be 
considered as electrically grounded through the bridge and trolley 
wheels and its respective tracks unless conditions such as paint or 
other insulating materials prevent reliable metal-to-metal contact. In 
this case a separate bonding conductor shall be provided.
    (b) Elevators, escalators, and moving walks--(1) Disconnecting 
means. Elevators, escalators, and moving walks shall have a single means 
for disconnecting all ungrounded main power supply conductors for each 
unit.
    (2) Control panels. If control panels are not located in the same 
space as the drive machine, they shall be located in cabinets with doors 
or panels capable of being locked closed.

[[Page 260]]

    (c) Electric welders--disconnecting means--(1) Motor-generator, AC 
transformer, and DC rectifier arc welders. A disconnecting means shall 
be provided in the supply circuit for each motor-generator arc welder, 
and for each AC transformer and DC rectifier arc welder which is not 
equipped with a disconnect mounted as an integral part of the welder.
    (2) Resistance welders. A switch or circuit breaker shall be 
provided by which each resistance welder and its control equipment can 
be isolated from the supply circuit. The ampere rating of this 
disconnecting means shall not be less than the supply conductor 
ampacity.
    (d) X-Ray equipment--(1) Disconnecting means--(i) General. A 
disconnecting means shall be provided in the supply circuit. The 
disconnecting means shall be operable from a location readily accessible 
from the X-ray control. For equipment connected to a 120-volt branch 
circuit of 30 amperes or less, a grounding-type attachment plug cap and 
receptacle of proper rating may serve as a disconnecting means.
    (ii) More than one piece of equipment. If more than one piece of 
equipment is operated from the same high-voltage circuit, each piece or 
each group of equipment as a unit shall be provided with a high-voltage 
switch or equivalent disconnecting means. This disconnecting means shall 
be constructed, enclosed, or located so as to avoid contact by employees 
with its live parts.
    (2) Control--Radiographic and fluoroscopic types. Radiographic and 
fluoroscopic-type equipment shall be effectively enclosed or shall have 
interlocks that deenergize the equipment automatically to prevent ready 
access to live current-carrying parts.