Top Electrician Interview Questions & Answers:
1. Working principle of rotary kiln under high temperature?
The rotary kiln in the application area, the numbers to be most cement industry. The whole process of cement production line summarized as 'two ground a burn,' with 'a burning,' is made by grinding good raw material, in the high temperature of kiln under the action of the process of burning become clinker. The equipment is also widely used in metallurgical, chemical, building, refractory material, environmental protection, and other industries.
The rotary kiln under high temperature overloaded alternating slow operation, and its annex equipment maintenance and thermal rail system related to the level of control of the rotary kiln working safety and efficiency. Therefore, rotary kiln cement produces the host, commonly known as the cement factory 'heart'.Rotary kiln cement industry forged in the main equipment burn the cement clinker. The stand or fall of sealing device directly affects the thermal rail system and run the rotary kiln capital. Strengthen rotary kiln daily maintenance data analysis of the pack; be helpful for equipment management work.
Cement kiln is used for making of cement clinker and there are dry and wet methods to make cement. Metallurgy chemical kiln is used in metallurgy industry and ironworks for lean iron ore, chromium ore and ferronickel ore calcimine. Rotary kiln is used for calcimine of high aluminum vandal ochre in refractory material industry; for calcimine of calotte and aluminum hydroxide in aluminum manufacturer; for claiming of chrome sand ore and chrome powder ore in chemical plant.Lime kiln is used for baking active lime and dolomite in the steel factory and ferroalloy factory.
Rotary kiln is the main equipment for calcining cement clinker and it can be used widely for cement industry ,metallurgy industry ,chemical industry , etc.Which can be divided into cement kiln ,metallurgy chemical kiln and lime kiln according to different materials.
2. What is the difference between fuse and circuit breaker?
Fuse:
A fuse has a wire that melts with the heat of a short circuit or high current and interrupts the circuit. Once melted, you have to replace it.
Circuit Breaker:
A circuit breaker interrupts the current without melting ( a pair of metal sheets with different thermal expansion coefficient, for example) and can be reset.
3. What services do you provide?
We provide the following:…
► Residential electrical work, central heating, cooling and air filtration
► Convenient, secure online self-scheduling for all your electrical needs
► Extended hours of operation: 7am -7pm
► Discounted member rates on labor and services
► A Home Electrical Safety Survey of all electrical systems for members
The Electrician is a home electrical service created by The Electrician Service Co. Inc. serving homeowners, in Nassau and Suffolk Counties.
This is used to describe the size and quantity of conductors
in a cable. The first number specifies the gauge. The second
the number of current carrying conductors in the wire - but
remember there's usually an extra ground wire. "14-2" means
14 gauge, two insulated current carrying wires, plus bare ground.
-2 wire usually has a black, white and bare ground wire. Sometimes
the white is red instead for 220V circuits without neutral. In
the latter case, the sheath is usually red too.
-3 wire usually has a black, red, white and bare ground wire.
Usually carrying 220V with neutral.
6. Breakers? Ca not I use fuses?
Statistics show that fuse panels have a significantly higher
risk of causing a fire than breaker panels. This is usually
due to the fuse being loosely screwed in, or the contacts
corroding and heating up over time, or the wrong size fuse
being installed, or the proverbial "replace the fuse with a
penny" trick.
Since breakers are more permanently installed, and have better
connection mechanisms, the risk of fire is considerably less.
Fuses are prone to explode under extremely high overload. When
a fuse explodes, the metallic vapor cloud becomes a conducting
path. Result? From complete meltdown of the electrical panel,
melted service wiring, through fires in the electrical
distribution transformer and having your house burn down.
Breakers won't do this.
7. What does a fuse or breaker do? What are the differences?
Fuses and circuit breakers are designed to interrupt the power
to a circuit when the current flow exceeds safe levels. For
example, if your toaster shorts out, a fuse or breaker should
"trip", protecting the wiring in the walls from melting. As
such, fuses and breakers are primarily intended to protect the
wiring -- UL or CSA approval supposedly indicates that the
equipment itself won't cause a fire.
Fuses contain a narrow strip of metal which is designed to melt
(safely) when the current exceeds the rated value, thereby
interrupting the power to the circuit. Fuses trip relatively
fast. Which can sometimes be a problem with motors which have
large startup current surges. For motor circuits, you can use
a "time-delay" fuse (one brand is "fusetron") which will avoid
tripping on momentary overloads. A fusetron looks like a
spring-loaded fuse. A fuse can only trip once, then it must be
replaced.
Inside the panel, connections are made to the incoming wires.
These connections are then used to supply power to selected
portions of the home. There are three different combinations:
1) one hot, one neutral, and ground: 110V circuit.
2) two hots, no neutral, and ground: 220V circuit.
3) two hots, neutral, and ground: 220V circuit + neutral,
and/or two 110V circuits with a common neutral.
9. My house does not meet some of these rules and regulations.
Do I have to upgrade?
In general, there is no requirement to upgrade older dwellings,
though there are some exceptions (ie: smoke detectors in some
cases). However, any new work must be done according to the
latest electrical code. Also, if you do ``major'' work, you
may be required to upgrade certain existing portions or all
of your system. Check with your local electrical inspector.
Every electrical device or component must be certified by the
Canadian Standards Association (or recognized equivalent) before
it can be sold in Canada. Implicit in this is that all wiring
must be done with CSA-approved materials. They perform testing
similar to the UL (a bit more stringent), except that CSA (or
recognized equivalent) approval is required by law.
Again, like the UL, if a fire was caused by non-CSA-approved
equipment, your insurance company may not have to pay the
claim.
Note: strictly speaking, there usually is a legal way around
the lack of a CSA sticker. In some cases (eg: Ontario), a
local hydro inspection prior to purchase, or prior to use, is
acceptable. The hydro inspector will affix a "hydro sticker"
to the unit, which is as good as CSA approval. But it costs
money - last I knew, $75 per unit inspected.
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