437-002-2321 Power Generation Installations This rule provides additional requirements and related work practices for power generating plants. (1) Interlocks and other safety devices. (a) Interlocks and other safety devices must be maintained in a safe, operable condition. (b) No interlock or other safety device may be modified to defeat its function, except for test, repair, or adjustment of the device. (2) Changing brushes. Before exciter or generator brushes are changed while the generator is in service, the exciter or generator field must be checked to determine whether a ground condition exists. The brushes may not be changed while the generator is energized if a ground condition exists. (3) Access and working space. The employer must provide and maintain sufficient access and working space around electric equipment to permit ready and safe operation and maintenance. NOTE to paragraph (3) of this rule: American National Standard: National Electrical Safety Code, ANSI/IEEE C2-2012 contains guidelines for the dimensions of access and working space about electric equipment in substations. Installations meeting the ANSI provisions comply with paragraph (3) of this rule. Oregon OSHA will determine whether an installation that does not conform to this ANSI standard complies with paragraph (3) of this rule based on the following criteria: Whether the installation conforms to the edition of ANSI C2 that was in effect when the installation was made; Whether the configuration of the installation enables employees to maintain the minimum approach distances, established by the employer under paragraph (3)(a) of this section, while the employees are working on exposed, energized parts, and; Whether the precautions taken when employees perform work on the installation provide protection equivalent to the protection provided by access and working space meeting ANSI/IEEE C2-2012. (4) Guarding of rooms and other spaces containing electric supply equipment. (a) Rooms and other spaces in which electric supply lines or equipment are installed must meet the requirements of paragraphs (4)(b) through (4)(e) of this rule under the following conditions: (A) If exposed live parts operating at 50 to 150 volts to ground are within 2.4 meters (8 feet) of the ground or other working surface inside the room or other space, (B) If live parts operating at 151 to 600 volts to ground and located within 2.4 meters (8 feet) of the ground or other working surface inside the room or other space are guarded only by location, as permitted under paragraph (5)(a) of this rule, or (C) If live parts operating at more than 600 volts to ground are within the room or other space, unless: (i) The live parts are enclosed within grounded, metal-enclosed equipment whose only openings are designed so that foreign objects inserted in these openings will be deflected from energized parts, or (ii) The live parts are installed at a height, above ground and any other working surface, that provides protection at the voltage on the live parts corresponding to the protection provided by a 2.4-meter (8-foot) height at 50 volts. (b) Fences, screens, partitions, or walls must enclose the rooms and other spaces so as to minimize the possibility that unqualified persons will enter. (c) Unqualified persons may not enter the rooms or other spaces while the electric supply lines or equipment are energized. (d) The employer must display signs at entrances to the rooms and other spaces warning unqualified persons to keep out. (e) The employer must keep each entrance to a room or other space locked, unless the entrance is under the observation of a person who is attending the room or other space for the purpose of preventing unqualified employees from entering. (5) Guarding of energized parts. (a) The employer must provide guards around all live parts operating at more than 150 volts to ground without an insulating covering unless the location of the live parts gives sufficient clearance (horizontal, vertical, or both) to minimize the possibility of accidental employee contact. NOTE to paragraph (5)(a): American National Standard: National Electrical Safety Code, ANSI/IEEE C2-2002 contains guidelines for the dimensions of clearance distances about electric equipment in substations. Installations meeting the ANSI provisions comply with paragraph (5)(a) of this rule. Oregon OSHA will determine whether an installation that does not conform to this ANSI standard complies with paragraph (5)(a) of this rule based on the following criteria: Whether the installation conforms to the edition of ANSI C2 that was in effect when the installation was made; Whether each employee is isolated from energized parts at the point of closest approach; and Whether the precautions taken when employees perform work on the installation provide protection equivalent to the protection provided by horizontal and vertical clearances meeting ANSI/IEEE C2-2002. (b) Except for fuse replacement and other necessary access by qualified persons, the employer must maintain guarding of energized parts within a compartment during operation and maintenance functions to prevent accidental contact with energized parts and to prevent dropped tools or other equipment from contacting energized parts. (c) Before guards are removed from energized equipment, the employer must install barriers around the work area to prevent employees who are not working on the equipment, but who are in the area, from contacting the exposed live parts. (6) Water or steam spaces. The following requirements apply to work in water and steam spaces associated with boilers: (a) A designated employee must inspect conditions before work is permitted and after its completion. Eye protection, or full face protection if necessary, must be worn at all times when condenser, heater, or boiler tubes are being cleaned. (b) Where it is necessary for employees to work near tube ends during cleaning, shielding must be installed at the tube ends. (7) Chemical cleaning of boilers and pressure vessels. The following requirements apply to chemical cleaning of boilers and pressure vessels: (a) Areas where chemical cleaning is in progress must be cordoned off to restrict access during cleaning. If flammable liquids, gases, or vapors or combustible materials will be used or might be produced during the cleaning process, the following requirements also apply: (A) The area must be posted with signs restricting entry and warning of the hazards of fire and explosion; and (B) Smoking, welding, and other possible ignition sources are prohibited in these restricted areas. (b) The number of personnel in the restricted area must be limited to those necessary to accomplish the task safely. (c) There must be ready access to water or showers for emergency use. NOTE to paragraph (7)(c): See 1910.141 and 437-002-0141 for requirements that apply to the water supply and to washing facilities. (d) Employees in restricted areas must wear protective equipment meeting the requirements of Division 2/I and including, but not limited to, protective clothing, boots, goggles, and gloves. (8) Chlorine systems. (a) Chlorine system enclosures must be posted with signs restricting entry and warning of the hazard to health and the hazards of fire and explosion. NOTE to paragraph (8)(a): See Division 2/Z for requirements necessary to protect the health of employees from the effects of chlorine. (b) Only designated employees may enter the restricted area. Additionally, the number of personnel must be limited to those necessary to accomplish the task safely. (c) Emergency repair kits must be available near the shelter or enclosure to allow for the prompt repair of leaks in chlorine lines, equipment, or containers. (d) Before repair procedures are started, chlorine tanks, pipes, and equipment must be purged with dry air and isolated from other sources of chlorine. (e) The employer must ensure that chlorine is not mixed with materials that would react with the chlorine in a dangerously exothermic or other hazardous manner. (9) Boilers. (a) Before internal furnace or ash hopper repair work is started, overhead areas must be inspected for possible falling objects. If the hazard of falling objects exists, overhead protection such as planking or nets must be provided. (b) When opening an operating boiler door, employees must stand clear of the opening of the door to avoid the heat blast and gases which may escape from the boiler. (10) Turbine generators. (a) Smoking and other ignition sources are prohibited near hydrogen or hydrogen sealing systems, and signs warning of the danger of explosion and fire must be posted. (b) Excessive hydrogen makeup or abnormal loss of pressure must be considered as an emergency and must be corrected immediately. (c) A sufficient quantity of inert gas must be available to purge the hydrogen from the largest generator. (11) Coal and ash handling. (a) Only designated persons may operate railroad equipment. (b) Before a locomotive or locomotive crane is moved, a warning must be given to employees in the area. (c) Employees engaged in switching or dumping cars may not use their feet to line up drawheads. (d) Drawheads and knuckles may not be shifted while locomotives or cars are in motion. (e) When a railroad car is stopped for unloading, the car must be secured from displacement that could endanger employees. (f) An emergency means of stopping dump operations must be provided at railcar dumps. (g) The employer must ensure that employees who work in coal- or ash-handling conveyor areas are trained and knowledgeable in conveyor operation and in the requirements of paragraphs (11)(h) through (11)(l) of this rule. (h) Employees may not ride a coal or ash-handling conveyor belt at any time. Employees may not cross over the conveyor belt, except at walkways, unless the conveyor's energy source has been deenergized and has been locked out or tagged in accordance with paragraph (d) of this rule. (i) A conveyor that could cause injury when started may not be started until personnel in the area are alerted by a signal or by a designated person that the conveyor is about to start. (j) If a conveyor that could cause injury when started is automatically controlled or is controlled from a remote location, an audible device must be provided that sounds an alarm that will be recognized by each employee as a warning that the conveyor will start and that can be clearly heard at all points along the conveyor where personnel may be present. The warning device must be actuated by the device starting the conveyor and must continue for a period of time before the conveyor starts that is long enough to allow employees to move clear of the conveyor system. A visual warning may be used in place of the audible device if the employer can demonstrate that it will provide an equally effective warning in the particular circumstances involved. However if the employer can demonstrate that the system's function would be seriously hindered by the required time delay, warning signs may be provided in place of the audible warning device. If the system was installed before January 31, 1995, warning signs may be provided in place of the audible warning device until such time as the conveyor or its control system is rebuilt or rewired. These warning signs must be clear, concise, and legible and must indicate that conveyors and allied equipment may be started at any time, that danger exists, and that personnel must keep clear. These warning signs must be provided along the conveyor at areas not guarded by position or location. (k) Remotely and automatically controlled conveyors, and conveyors that have operating stations which are not manned or which are beyond voice and visual contact from drive areas, loading areas, transfer points, and other locations on the conveyor path not guarded by location, position, or guards must be furnished with emergency stop buttons, pull cords, limit switches, or similar emergency stop devices. However, if the employer can demonstrate that the design, function, and operation of the conveyor do not expose an employee to hazards, an emergency stop device is not required. (A) Emergency stop devices must be easily identifiable in the immediate vicinity of such locations. (B) An emergency stop device must act directly on the control of the conveyor involved and may not depend on the stopping of any other equipment. (C) Emergency stop devices must be installed so that they cannot be overridden from other locations. (l) Where coal-handling operations may produce a combustible atmosphere from fuel sources or from flammable gases or dust, sources of ignition must be eliminated or safely controlled to prevent ignition of the combustible atmosphere. NOTE to paragraph (11)(l): Locations that are hazardous because of the presence of combustible dust are classified as Class II hazardous locations. See 1910.307. (m) An employee may not work on or beneath overhanging coal in coal bunkers, coal silos, or coal storage areas, unless the employee is protected from all hazards posed by shifting coal. (n) An employee entering a bunker or silo to dislodge the contents must wear a body harness with lifeline attached. The lifeline must be secured to a fixed support outside the bunker and must be attended at all times by an employee located outside the bunker or facility. (12) Hydroplants and equipment. Employees working on or close to water gates, valves, intakes, forebays, flumes, or other locations where increased or decreased water flow or levels may pose a significant hazard must be warned and must vacate such dangerous areas before water flow changes are made. Statutory/Other Authority: ORS 654.025(2) & 656.726(4) Statutes/Other Implemented: ORS 654.001 - 654.295 History: OSHA 3-2015, f. 10-9-15, cert. ef. 1-1-16