259-285 Flashcards
- What should be considered when selecting a motor?
Horsepower, Voltage, RPM, FLA, Shaft size, environmental conditions, Frame size and Rotation.
- How do you reverse rotation of a single-phase motor? How do you reverse the rotation of a three-phase motor?
On a single phase motor:
1. Shift the brushes according to marks on the motor frame or brush holder.
2. Reverse two of the wires coming from inside the motor.
3. Follow the manufacturer’s instructions.
On a three phase motor, interchange two of the line voltage leads.
- List four ways to safeguard electrical equipment. What is single phasing and give three examples why a motor would single phase.
Overload relays, low voltage releases, fuses and circuit breakers.
Single phasing is when power on one “leg” of a three phase motor is lost. It could be caused by a burned contact, a blown fuse or a broken wire.
- What is a synchronous motor?
It is an AC machine. Basically the same as an alternator. The motor is locked into the same speed as the alternator supplying the power and has little or no starting torque
- What is an alternator? What is a generator? What is the most common way to generate electricity? How do you protect generators when shorted to ground? SPO 7 8
It is a synchronous generator that delivers alternating current of a frequency directly proportional to its rotating speed.
A generator changes mechanical energy into electrical energy.
Steam power plants using fossil fuels and steam turbines.
Fuses, Circuit breakers and Overloads.
- How are ball bearing motors lubricated?
Remove grease plugs and pump grease through the bearing until clean grease comes out. Run the motor about one hour, wipe off excess grease and replace the plugs.
- What is OSHA? LPB 2-3 BOW 3-4
Occupational Safety and Health Administration
is a federal agency requiring employers to provide a safe environment, free of hazards likely to cause serious harm to their employees.
- What is EPA? LPB 2-3
Environment Protection Agency
Is a federal agency set up to control and abate pollution in the areas of air, water, solid waste, pesticides, radiation and toxic substances.
- Explain the N.F.P.A. hazard system. LPB 2-3 BOW 3-4
The colors and numbers indicate the hazard and the degree of severity.
Blue is health
Red is fire
Yellow is reactivity
White is properties and hazards of particular materials.
A number indicates the degree of severity. 4 – being severe hazard down to 0 – being no hazard.
(Note: Learn all of them and practice drawing the fire diamond!!)
- Draw a fire safety floor plan for a boiler room. What are the four major areas? LPB 2-3
It must include: Fire water main, domestic water main, gas main, electrical breaker, stairwells, exits, emergency shutdown buttons by exits, oil storage and shut-offs, fire extinguisher locations, spill stations, shower and eye-wash station and directional arrow.
Major four are:
Locations of fire alarms and fire extinguishers.
Fire main
Main electrical breaker
Exits
- What is an A-type fire? What is a B-type fire? What is a C-type fire? LPB 2-3 BOW 34
A type - Paper & wood
BC type – Oil & electrical
ABC type – Electrical
- Name three types of extinguishers and list what they are used for. How often do they need to be inspected and who inspects them? LPB 2-3 BOW 3-4
A type – Paper & wood BC type - Oil & electrical ABC type – Paper, wood, oil & electrical HALON – Electrical & computers CO2 – Oil & electrical Once a year if not used and by a licensed inspector
- What is a dry sprinkler system?
A system charged with air. Usually found in places where the temperature falls below the freezing point of water. When a head opens, there is a pressure drop in the line which opens the water valve.
- How far apart are the heads on a sprinkler system? How much area does a sprinkler head cover?
12’ to 15’ depending on usage of the space & the height of the sprinkler system.
Each covers 130 to 200 sq. ft.
- If an electrical panel caught fire in your boiler room what are the first two things you would do?
Cut power to the area. Call 911 even if the fire is out.