Safety Meeting Topics Standby Generator Safety Slide Show Notes Welcome to this training session on Standby Generator safety. This session is intended for lineworkers and the Public Utility and Safety personnel who may be affected by standby generators. It provides important information about standby generators and the dangers of backfeed onto lines and equipment. Institute for Safety in Powerline Construction 3504 Parliament Ct. • Alexandria, LA • ispconline.com

Learning Objectives You will be able to: Recognize hazards associated with adding a generation device to a facility that is currently connected to a power grid Avoid potential accidents Help protect lineworkers during outage repair situations Slide Show Notes By the end of the training session, you will be able to: Recognize hazards associated with adding a generation device to a facility that is currently connected to a power grid Avoid potential accidents Help protect lineworkers during outage repair situations

The ‘Double-Throw’ (Transfer) Switch Adding a standby generator to the electrical system of a home, farm or business requires a suitable ‘Transfer Switch’ to disconnect the electric loads from the power suppliers utility grid. This is a requirement of the National Electrical Code (see NEC Article 702-6) and all electric power suppliers, for two very good reasons: It prevents the back flow of current into the utility's lines during an outage, which could electrocute lineworkers restoring power. It prevents damage to the generator when normal electric service has been restored, which can destroy the generator. Slide Show Notes The transfer switch or disconnect switch from the electric grid is very important. Never use an extension cord with 2 male ends to plug into a system.

The ‘Double-Throw’ (Transfer) Switch Slide Show Notes:

The “Double-Throw” (Transfer) Switch For single-phase, 120/240 volt power, the Transfer Switch should be a double-pole, double-throw type. Double pole means that there are two pairs of wire lugs available for connection of hot conductors (see Fig. 1 next slide). The third wire (neutral wire) is continuous through the transfer enclosure, and is typically not switched (NEC Article 230- 83). The ground wire also passes through the switch enclosure to provide a safe and continuous ground connection.

The ‘Double-Throw’ (Transfer) Switch

The ‘Double-Throw’ (Transfer) Switch Double-Throw Transfer Switch Installation for 120/240 V, Single-Phase Service. Grounding electrode must be bonded according to National Electrical Code requirements and local regulations.

The ‘Double-Throw’ (Transfer) Switch A three-phase generator would require a three- pole, double-throw switch. Some electric services use current transformer (CT) metering. This may require the use of a ‘Pole Top Transfer Switch’. The operation of these switches is essentially the same, except that an extended manual switch lever is needed to allow the user to operate the switch from ground level.

Pole Top Transfer Switch Slide Show Notes

Load Factors The size of the transfer switch is determined by the loads to be served. If a central meter pole location is used, the transfer switch rating must be equal to the size of the main service (typically 100, 200 or 400 amperes). If the standby system is designed to supply an individual building, or even a single circuit, the transfer switch will be sized to the total ampere rating of the connected loads.

Built-in Transfer Switches If an engine-driven generator with automatic start-up is used, the transfer switch is normally built into the automatic controls of the system. In this case, the transfer switch must be large enough to handle all electrical loads, size the switch to match the rating of conductors which supply normal power to the building(s) or farmstead. Slide Show Notes

Grounding Considerations All standby generators should be grounded using #6 solid copper wire and an 8-foot ground rod, which must be properly bonded to the electrical grounding system with approved clamp/connections to assure good electrical contact. Cover all generator openings with wire mesh to exclude rodent entry and potential damage. Keep these openings free of debris that might restrict the cooling of the unit. Slide Show Notes

Other Safety Issues Keep all guards and shields in place to protect the operator from moving parts; Never run a generator in a basement or other enclosed area. Fumes that are not easily detected can be lethal to sleeping occupants and others; Never shut-off the generator under load; Never store fuel near the generator, unless a proper container or fuel tank is used; Slide Show Notes

Other Safety Issues Never re-fuel a generator when hot or while the engine is running; Use extreme care under wet conditions; making your body a path to ground can cause a fatal shock; On tractor-driven units, always turn off the tractor and PTO control to service the generator. Set the tractor brake before starting the generator.

OSHA Regulations 1910.269 (w) (7) (as of May, 2008): Backfeed. If there is a possibility of voltage backfeed from sources of cogeneration or from the secondary system (for example, backfeed from more than one energized phase feeding a common load), the requirements of paragraph (l) of this section apply if the lines or equipment are to be worked as energized, and the requirements of paragraphs (m) and (n) of this section apply if the lines or equipment are to be worked as deenergized. 1910.333 (c) (as of May, 2008) Working on or near exposed energized parts. (1) "Application." This paragraph applies to work performed on exposed live parts (involving either direct contact or by means of tools or materials) or near enough to them for employees to be exposed to any hazard they present. (2) "Work on energized equipment." Only qualified persons may work on electric circuit parts or equipment that have not been deenergized under the procedures of paragraph (b) of this section. Such persons shall be capable of working safely on energized circuits and shall be familiar with the proper use of special precautionary techniques, personal protective equipment, insulating and shielding materials, and insulated tools., personal protective equipment, insulating and shielding materials, and insulated tools. Slide Show Notes

Please Work Safe Safety Meeting Topics Slide Show Notes Institute for Safety in Powerline Construction 3504 Parliament Ct. • Alexandria, LA • ispconline.com