Chat with AIExam 8: Basic Motor Controls
Motor control circuits can be divided into two major categories, one of which is_______ .
(76) 
VerifiedA
Bimetal strip-type overload relays generally permit the trip current to be adjusted to between 85% and_______ % of the heater rating.
(76) VerifiedC
What are the differences between the two types of thermal overload relays?
(79) VerifiedThe solder pot-type overload relay works by placing a brass shaft inside a brass tube. A serrated wheel is attached to the brass shaft. Solder is used to bond the brass shaft to the brass tube. A lever arm between the contacts and serrated wheel holds the contacts in place. If the motor current becomes excessive, the heater will melt the solder and permit the serrated wheel to turn, causing the normally closed auxiliary contacts to open. The bimetal strip-type overload uses a bimetal strip to open the normally closed auxiliary contacts if the motor current becomes excessive. There are other differences between the solder pot-type and bimetal strip-type overload relay.
Bimetal strip-type overload relays generally permit the trip current to be adjusted to between 85% and 115% of the heater rating. Another difference is that bimetal strip-type overloads can generally be set to permit the contacts to reset automatically or manually after the bimetal strip has cooled sufficiently. Generally, the relay is adjusted for manual reset. Automatic reset should be used only if the sudden starting of a motor will not cause danger to personnel or damage equipment.
In a basic air-conditioning circuit there are two_______ switches in order to protect the compressor from extremes.
(95) A magnetic contactor or relay is basically an electrical _______that closes a set of contacts when the coil is energized.
(67) What are the major rules that should be followed when reading a schematic diagram?
(73) The current-sensing section of the overload relay can be_______ , electronic, or thermal.
(89) _______switches are indicated by drawing a wedge shape below the movable contact of a switch symbol.
(79) If a contact is to be drawn_______ it is drawn so that the movable contact is above and touching the stationary contact.
(78) _______are intended to open the circuit when the current exceeds the full-load current rating of the motor by 115 percent to 125 percent.
(74) A pressure switch is drawn by connecting a _______to a line.
(70) What is the difference between overload protection and fuse or circuit protection?
(84) All overload relays contain two separate sections, the_______ section and the control contact section.
(76) What does the abbreviation NO stand for with reference to switch contacts?
(76) The _______control circuit is often referred to as the basic circuit.
(82) _______diagrams show components in their electrical sequence without regard for physical location.
(64) There are two types of thermal overload relays, the _______type and the bimetal strip type.
(78) If the symbol shows the movable contact touching but below the stationary contact, this indicates that the switch is ____.
(86) 
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