Disconnect switch operation

A hand-operated power disconnect device shall disconnect the whole equipment from main input supply power. There are several possibilities. A user-accessible disconnect switch located on the front of the product is preferred but not the only option. Some of the power disconnect methods are ... 

B. Mains Disconnect Switches Mains disconnect switches are required on all machines to isolate the entire electrical equipment. The OFF position must be lockable, lEC symbols for ON/OFF positions must be present and meet the relevant EU standards for construction and operation, which is assured if the device... 

Centrifuges should be properly installed and must be operated only by trained personnel. It is important that the load be balanced each time the centrifuge is used and the lid be closed while the rotor is in motion. The disconnect switch must be working properly to shut off the equipment when the top is opened, and the manufacturer s instructions for safe operating speeds must be followed. 

A mechanical device that physically prevents the transmission or release of energy. They typically include, but are not limited to, the following A manually operated electrical circuit breaker a disconnect switch a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently a line valve a block and any similar device used to block or isolate energy. Push buttons, selector switches, and other control circuit type devices are not considered energy isolating devices. Enforcement... 

Bipolar electrolyzers can be isolated from the alternating current (AC) side or by direct current (DC) disconnect switches and do not always require portable switches or jumper bus. While not strictly required, the latter may be used to allow one modular zone of an electrolyzer to be taken out of service while the rest stays in operation. This is in the interest of reducing the loss in production during replacement of cells. The large capacity of individual bipolar electrolyzers means that relatively few units are installed. Taking an entire electrolyzer out of production may cause a significant drop in output. 

Any mechanical device that physically prevents the transmission or release of energy. These include, but are not limited to, manually-operated electrical circuit breakers, disconnect switches, line valves, and blocks. 

Seals used in hazardous operating areas to prevent hazardous gases from entering the electrical enclosure (motor starter, disconnect switch, motor. 

Disconnect Switch. The external operating handle must be capable of opening the switch. If it fails or if visual inspection after opening indicates deterioration beyond normal, such as overheating, contact blade or jaw pitting, insulation breakage, or charring, the switch must be replaced. 

In some operations, the movement of a simple throw disconnect switch to the off mode is a step sufficient to isolate the machine or equipment from the energy source as required by 1910.147(d)(3). In other cases, a series of predetermined steps may be necessary to achieve an orderly shutdown of a machine or piece of equipment in order to safely perform the servicing or maintenance work. This would be the case for the hydraulic pump overhaul or hydraulic line maintenance tasks. 

Energy-isolating device A mechanical device that physically prevents the release or transmission of energy. Some examples include a manually operated circuit breaker, a disconnect switch, a line valve, or a block. The following are not energy-isolating devices push buttons, selector switches, and other circuit-control devices. 

In both the above methods a speed-operated centrifugal switch is provided with auxiliary winding to disconnect the winding when the motor has reached about 15-85% of its rated speed. Figure 1.24(e) shows a general view. 

Replace the stopper and switch on the water-jet pump (very slow operation). When the entire phosphorus has reacted, disconnect the pump and dissolve the phosphorous anhydride gathered in tube 4 and U-tubes 5 and 6 in 10-20 ml of distilled water. Filter the solution through a paper filter and keep it for further experiments. 

Turn on the 02-electrode system and allow the circuitry to warm up or stabilize for 5 min. Check the operation of the recorder during this interval. Then set the recorder on pen and set the zero point adjustment control of the recorder to achieve a zero setting on the recorder during zero output from the 02-electrode system. This usually requires that you disconnect the 02-electrode system from the recorder or switch a zero output control on the 02-electrode system. 

Unattended operations must be planned with automatic safety switches that prevent serious damage (fire, flooding, explosion) in case of accidental equipment failure or interruption of utility services such as electricity, water, or gas supplies. Of special concern are the constant flow of cooling water and the operation of high-temperature baths. In the case of water flow, a device should be installed in the water line to (1) automatically regulate the water pressure (so as to avoid surges that might disconnect or rupture a water hose), and (2) automatically turn off electrical connections and water-supply valves in case of a total loss of water supply. In the case of hot thermostat baths or ovens, a sensor/control device should be installed that automatically turns off the electrical power to all heaters if the temperature exceeds some preset upper limit. 

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