Subpart K
A readily accessible disconnecting means must be provided between the runway contact conductors and the power supply. Employers must ensure that someone can quickly reach and operate that disconnect to isolate the runway conductors from the power source for maintenance or emergency purposes. See the requirement in 1926.406(a)(1)(i).
Yes. Each crane or monorail hoist must have a disconnecting means in the leads from the runway contact conductors or other power supply that is capable of being locked in the open position so the power cannot be restored while maintenance or servicing is performed. This protects workers from unexpected energization. See 1926.406(a)(1)(ii).
If the extra disconnect isn’t readily accessible from the operating station, means must be provided at the operating station to open the power circuit to all motors of the crane or monorail hoist. In other words, the operator must be able to deenergize the unit from their station. See 1926.406(a)(1)(ii)(A).
The additional disconnecting means may be omitted only if all three conditions are met: the unit is floor controlled, the unit is within view of the power supply disconnecting means, and no fixed work platform has been provided for servicing the unit. If any of these conditions is not met, the extra disconnect is required. See 1926.406(a)(1)(ii)(B) and the specific criteria at 1926.406(a)(1)(ii)(B)(1)-(3).
A limit switch or other device must be installed to prevent the load block from passing the safe upper limit of travel on any hoisting mechanism. This device must reliably stop upward motion to avoid overtravel and potential accidents. See 1926.406(a)(2).
You must provide a minimum of 2 feet 6 inches (762 mm) of working space in the direction of access to live parts that may require examination, adjustment, servicing, or maintenance while energized. If controls are enclosed in cabinets, the door(s) must open at least 90 degrees or be removable, or the installation must provide equivalent access. See 1926.406(a)(3).
All exposed metal parts of cranes, monorail hoists, hoists, and accessories (including pendant controls) must be metallically joined together into a continuous conductor so the entire crane or hoist is grounded in accordance with grounding requirements. Moving parts with metal-to-metal bearing surfaces are considered electrically connected through those bearings for grounding unless they are removable accessories. See the grounding requirement in 1926.406(a)(4) and the grounding standard at 1926.404(f).
A separate bonding conductor must be provided when conditions such as paint or other insulating materials prevent reliable metal-to-metal contact between the trolley/bridge wheels and their tracks; otherwise, the frames are considered grounded through wheel-to-track contact. Inspect wheel-track contact and add bonding if contact is unreliable. See 1926.406(a)(4).
Each elevator, escalator, and moving walk must have a single means for disconnecting all ungrounded main power supply conductors for that unit. That single disconnect isolates the unit’s power for maintenance and emergency shutdown. See 1926.406(b)(1).
If control panels are not in the same space as the drive machine, they must be located in cabinets with doors or panels capable of being locked closed to restrict access and protect against unauthorized or accidental contact. See 1926.406(b)(2).
For motor-generator arc welders and for AC transformer and DC rectifier arc welders that do not have an integral disconnect, a disconnecting means must be provided in the supply circuit; for resistance welders, a switch or circuit breaker must be provided to isolate each welder and its control equipment from the supply circuit. These disconnects let maintenance personnel safely deenergize welding equipment. See 1926.406(c)(1) and 1926.406(c)(2).
For X-ray equipment on a 120-volt branch circuit of 30 amperes or less, a grounding-type attachment plug cap and receptacle of proper rating may serve as the required disconnecting means, provided the disconnect is readily accessible from the X-ray control. See 1926.406(d)(1)(i).
Each piece of equipment or each group of equipment must be provided with a high-voltage switch or equivalent disconnecting means that is constructed, enclosed, or located to avoid employee contact with live parts. This ensures individual units can be isolated safely. See 1926.406(d)(1)(ii).
Radiographic and fluoroscopic-type X-ray equipment must be effectively enclosed or equipped with interlocks that automatically deenergize the equipment to prevent ready access to live current-carrying parts. This protects employees from accidental exposure to high voltage. See 1926.406(d)(2).
The disconnecting means for X-ray equipment must be operable from a location that is readily accessible from the X-ray control, so the operator or attendant can quickly deenergize equipment if necessary. See 1926.406(d)(1)(i).
The ampere rating of the disconnecting means must be at least equal to the supply conductor ampacity; in other words, the disconnect cannot be rated lower than the conductors it serves. This prevents overheating and ensures safe disconnection. See the general statement about ampere rating in 1926.406(d) and the specific X-ray disconnect location requirement at 1926.406(d)(1)(i).
‘‘Equivalent access’’ means the installation must provide a method that allows safe and adequate working space and access to live parts for examination, adjustment, servicing, or maintenance comparable to opening cabinet doors 90 degrees or removing them. Employers should ensure technicians can reach and work on live parts safely, and document the alternative access method. See 1926.406(a)(3).
No. Moving parts other than removable accessories or attachments with metal-to-metal bearing surfaces are considered electrically connected through those bearing surfaces for grounding purposes; removable accessories are excluded and may need separate bonding or grounding measures. See 1926.406(a)(4).
The employer should verify three things: that the unit is indeed floor controlled, that the unit remains within clear view of the power supply disconnecting means under normal operations, and that there is no fixed work platform provided for servicing the unit. If any check fails, the extra, lockable disconnect in the leads is required. Document these checks as part of the safety assessment. See the exception criteria at 1926.406(a)(1)(ii)(B)(1)-(3).