Round 3 Flashcards
What is the function of a 59 device?
Overvoltage
In the rare situation in which an employee who installed a lockout/tagout device is unable to remove that device, another person may remove it under the direction of the _____, provided that the ____ strictly adheres to the specific procedures outlined in the standard.
employer, employer
What two conditions must be met for a protective relay device 67 to cause tripping?
Overcurrent in a predetermined direction
A piece of wire that is 0.001 inches in diameter and 12 inches long is one mil-foot.(T/F)
True
When the thermal memory is switched on for digital overcurrent protective devices (OCPDs) used on low-voltage circuit breakers, what effect will it have on the long time delay (LTD) operating time?
It will decrease LTD somewhat
What must be provided in a confined space that is over 5 feet deep?
A mechanical means of retrieval
Decreasing the opening time of the overcurrent protective device will decrease Arc-Flash hazards.(T/F)
True
The neutral conductor is often grounded at the service entrance switchboard.(T/F)
True
During a short-time delay test on a low voltage circuit breaker, you observe a trip time of 0.060 seconds at 1.5X pickup, your expected time was 0.200 seconds. What is most likely the problem?
Restraint signal
Cabinets are electrical assemblies designed to be placed in panelboards.(T/F)
False
Which one of the following is damaging to many insulating materials used in high-voltage rotating machines?
Corona
A given 480V motor control center is fed by a transformer with an available fault current of 48kA and is protected by a circuit breaker with a fault clearing time of 0.025 seconds. According to NFPA 70E, which of the following would be considered an acceptable flash protection boundary for this equipment?
5 feet
A relay device number 51 is connected to an 800/5 CT. The relay is set to time dial 3 and tap 10. What primary current must flow to cause the relay to start timing out?
1600A
Which of the following batteries is also referred as a Leclanche Battery?
Carbon zinc
A confined space entry permit must be signed by:
Trained individual acting as entry supervisor
The top step of a tied-off ladder shall:
Not be used as a step
An emergency transfer switch shall supply ______.
emergency loads
Facing the low-voltage side of a transformer with additive polarity, where would you find X3?
Over the left shoulder
The breaking capacity of a circuit breaker is usually expressed in:
MVA
Conductive lube must be applied to circuit breaker stabs to keep__________ at a minimum in the circuit path.
resistance
A UPS system would be best described by which of the following?
A system that converts AC to DC and then inverts DC back to AC
The grounded conductor is one of the two conductors through which normal circuit current flows.(T/F)
True
ASTM test method D971 measures which of the following?
mN/m
When monitoring for confined space entries involving a descent into atmospheres that may be stratified, the atmospheric envelope should be tested a distance of approximately ____ in the direction of travel and to each side.
4 feet
