Book #7 Flashcards
(32 cards)
When referring to the capacity of communication cable, what does the term attenuation refer to?
The ratio of signal strength at the transmitting and receiving ends of the cable
What type of equipment should you use when installing a wall mounted light at 5m in a closed stairwell
Bakers platform
What causes a 3-phase motor to single-phase
An open line fuse
Why cant stainless steel be used as bonding material?
It is a material having a high resistivity value
To whom should the as-built drawings, short circuit study, coordination study and calibration test results be submitted to?
Engineer
A fuse has t5he following stamped on the body of the fuse, 200a, 600v, 12kaic HRCI-MISC what does the 200a stand for
Amps of continuous current
What device is used to limit high temperature in a hydronic heating system?
Aquastat
What field marked label dictates the personal protection equipment required for a service panel?
Arc Flash sticker
When examining a circuit board in an enclosure, oxidization was found on the circuit board. what is the most probable cause of oxidization?
Moisture is getting on the board
When performing scheduled preventative maintenance to locate overheating joints and sections of insulation deterioration, What type of instrument should you employ?
thermography
What type of of DC motor should not be used for belt drive applications?
Series
The purpose of a shading coil is to:
Prevent chatter and AC hum
A newly installed overload relay device causes frequent tripping, what should you do?
Change current rating
A magnetic blow-out coil is connected?
In series with the load
What kind of meter is used to test the specific gravity of a lead-acid battery?
Hydrometer
The most common heat sensing device used in room thermostats is the:
Bimetal strip
How do you safely dry out a damp air cooled dry type transformer?
Apply a small amount of voltage to primary under no load condition
A long spiral bimetal strip is desirable because:
exhibits more movement with a change of heat
To reverse a standard split-phase dual voltage motor, which wiring connections are interchanged?
T5 and T8
Which leads have to be interchanged in order to reverse a cumulative compound motor?
A1 and A2
What is the main purpose of the heat anticipator in a low-voltage thermostat?
to prevent overshooting of the preset temperature
For the installation of HVAC controls, what is normally determined by referencing electrical drawings?
location of thermostats
What would result if the correct polarity will not be observed during the installation of the signaling device of a class B fire alarm system?
Trouble signal will sound
When connecting a residential extra-low voltage thermostat, what does the G terminal designate?
Fan
