9
gfrost
Technical - Vocational - Education
Industrial Arts
ELECTRICAL INSTALLATION
& MAINTENANCE
Quarter 2 Module 1
Metallic and Non Metallic Conduit
TLE/EIM – Grade 9
Quarter 2 – Module 1: Bending Non-Metallic Conduit
First Edition, 2020
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Technical - Vocational - Education
Industrial Arts
9
ELECTRICAL INSTALLATION
& MAINTENANCE
Quarter 2 Module 1
Metallic and Non-Metallic Conduit
Introductory Message
For the facilitator:
Welcome to the EIM-9 Self-Engaging Module (SEM) on Metallic
and Non-metallic Conduit
This module was collaboratively designed, developed and
reviewed by educators both from public and private institutions to
assist you, the teacher or facilitator in helping the learners meet
the standards set by the K to 12 Curriculum while overcoming their
personal, social, and economic constraints in schooling.
This learning resource hopes to engage the learners into guided
and independent learning activities at their own pace and time.
Furthermore, this also aims to help learners acquire the needed
21st century skills while taking into consideration their needs and
circumstances.
In addition to the material in the main text, you will also see this
box in the body of the module:
Notes to the Teacher
This contains helpful tips or strategies
that will help you in guiding the
learners.
As a facilitator, you are expected to orient the learners on how to
use this module. You also need to keep track of the learners'
progress while allowing them to manage their own learning.
Furthermore, you are expected to encourage and assist the
learners as they do the tasks included in the module.
ii
For the learner:
Welcome to the EIM-9 Self-Engaging Module (SEM) on Metallic
and Non-metallic Conduit
This module was designed to provide you with fun and meaningful
opportunities for guided and independent learning at your own
pace and time. You will be enabled to process the contents of
the learning resource while being an active learner.
This module has the following parts and corresponding icons:
Let us Learn!
Let us Try!
Let us Study
This will give you an idea of the skills
or competencies you are
expected to learn in the module.
This part includes an activity that
aims to check what you already
know about the lesson to take. If
you get all the answers correct
(100%), you may decide to skip this
module.
This includes a brief drill or review to
help you link the current lesson with
the previous one; various ways of
introducing a new lesson such as a
story, a song, a poem, a problem
opener, an activity or a situation;
and a brief discussion of the lesson.
This aims to help you discover and
understand new concepts and
skills.
iii
Let us Practice
Let us Practice
More
Let us
Remember
Let us Assess
Let us Enhance
Let us Reflect
Answer Key to
the Activities
This comprises activities for guided
practice to solidify your
understanding and skills of the
topic. You may check the answers
to the exercises using the Answer
Key at the end of the module.
This comprises activities for
independent practice to solidify
your understanding and skills of the
topic. You may check the answers
to the exercises using the Answer
Key at the end of the module.
This includes questions or blank
sentence/paragraph to be filled in
to process what you learned from
the lesson.
This is a task which aims to evaluate
your level of mastery in achieving
the learning competency.
In this portion, another activity will
be given to you to enrich your
knowledge or skill of the lesson
learned.
This part contains the closing note
related to the lesson. It will help you
reflect the importance of the
concepts you have learned in this
module and its relevance to reallife situation.
This contains answers to all activities
in the module.
iv
At the end of this module you will also find:
References
This is a list of all sources used
in developing this module.
The following are some reminders in using this module:
1. Use the module with care. Do not put unnecessary mark/s on
any part of the module.
2. Don’t forget to answer Let Us Try! before moving on to the
other activities included in the module.
3. Read the instruction carefully before doing each task.
4. Observe honesty and integrity in doing the tasks and
checking your answers.
5. Finish the task at hand before proceeding to the next.
6. Return this module to your teacher/facilitator once you are
through with it.
If you encounter any difficulty in answering the tasks in this
module, do not hesitate to consult your teacher or facilitator.
Always bear in mind that you are not alone.
We hope that through this material, you will experience
meaningful learning and gain deep understanding of the
relevant competencies. You can do it!
v
Let Us Learn!
This module was designed and written with you in mind. It is
here to help you master how to install bulb controlled by 1 SPST.
The scope of this module permits it to be used in many different
learning situations. The language used recognizes the diverse
vocabulary level of students. The lessons are also arranged to
follow the standard sequence of the course. But the order in
which you read them can be changed to correspond with the
textbook you are now using.
This module has one lesson:
• Lesson 1- Bulb controlled by 1SPST.
After going through this module, you are expected to:
1. identify the different PVC bends.
2. Know how to bend Non-metallic Conduit.
1
Let Us Try!
TRUE or False
Direction: Write TRUE if the statement is correct and False if it is
false.
1. PVC is a flexible non-metallic conduit?
2. A reducer is a special kind of combination coupling.
3. LFNC is a thin-walled corrugated tubing that is moisture
resistant and flame retardant.
4. LFNC has a nominal rating of 6000V for conductors
5. ENT is type of tubing that uses fire to bend.
6. LFNC-B are not suitable for housing conductors
7. PVC conduits cannot be used in hazardous locations.
2
Lesson
2
Metallic and Non-Metallic
Conduit
Day 1
Let Us Study
Metallic Conduit
The term "electrical conduit" refers to durable tubing or other types of
enclosure used to protect and provide a route for individual electrical wiring
conductors. Conduit is typically required where wiring is exposed or where it
might be subject to damage. A conduit can be made of metal or plastic and
may be rigid or flexible. All conduit is installed with
compatible fittings (couplings, elbows, connectors) and electrical boxes,
usually made of the same or similar material. Conduit must be installed in
accordance with the National Electrical Code (NEC) and all applicable local
code rules.1
There are different types of conduit used commonly in residential and light
commercial wiring.
Types Metallic Conduit
Rigid Metal Conduit—RMC and IMC
Rigid metal conduit, or RMC, is heavy-duty galvanized steel tubing that is
installed with threaded fittings. It is typically used outdoors to provide
protection from damage and can also provide structural support for
electrical cables, panels, and other equipment. RMC is sold in 10- and 20foot lengths and has threads on both ends.
Intermediate metal conduit, or IMC, is a thinner, lighter-weight version of
rigid metal conduit and is approved for use in all of the same applications as
RMC. Because IMC is lighter and easier to work with than RMC, it is more
common in new construction.
3
https://www.ecmweb.com/content/article/20888282/the-basics-of-steel-conduit
Electrical Metallic Tubing—EMT
Another example of a rigid electrical conduit is EMT (electrical metal tubing),
which is most commonly made of galvanized steel but can also be
aluminum. EMT is also called "thin-wall" conduit because it is thin and
lightweight, especially compared to RMC. EMT is rigid but can be bent with
a simple tool called a conduit bender.
EMT is installed with couplings and fittings that are secured with setscrew
or compression-type fasteners. The tubing itself is not threaded like RMC
and IMC. Common sizes of EMT include 1/2-inch, 3/4-inch, and 1-inch. It
is commonly used for exposed indoor wiring runs in residential and light
commercial construction. If installed outdoors in exposed locations, it must
be assembled with special watertight fittings.
https://sebringdesignbuild.com/what-is-emt-conduit-and-do-i-need-to-use-it-for-my-project/
Flexible Metal Conduit—FMC and LFMC
Flexible metal conduit (FMC) is also called "Greenfield," after the name of its
inventor. It has a spiral construction that makes it flexible so it can snake
through walls and other structures. Standard FMC is used in dry indoor
locations, often for short runs between a wall box and a motor or fixed
appliance, such as a garbage disposer.
4
Liquid-tight flexible metal conduit (LFMC) is a special type of flexible
metal conduit that has a plastic coating and is used with sealed fittings to
make it watertight. It is commonly used with outdoor equipment, such as air
conditioner units.
https://professional-electrician.com/technical/question-time-flexible-metal-conduit/
Rigid PVC Conduit
Rigid polyvinyl chloride (PVC) is similar to plastic plumbing pipe and is
installed with plastic fittings that are glued in place. It can be bent after
being heated in a portable heater box. Because the conduit tubing and
fittings are glued together, the conduit assemblies can be watertight, making
PVC suitable for direct burial in the ground for many applications. It is also
allowed in corrosive environments.
https://www.indiamart.com/proddetail/rigid-pvc-conduit-pipe-16429992797.html
Cutting and Bending Conduit
An ordinary hacksaw or special wheel pipe cutter is used for cutting, and a
ratchet type of mechanical die is used for threading the cut ends. Bending
can be done manually, using a bending tool commonly called a hickey or
hydraulically. A hydraulic bender is recommended for making smooth and
accurate bends.
5
Conduit Bender
(HICKEY)
Hydraulic Bender
Tube Cutter/Pipe
Cutter
HACKSAW
6
Non-metallic Conduit
An electrical conduit is a tube used to protect and route electrical wiring in a
building or structure. It is generally installed by electricians at the site of
installation of electrical equipment and its specifications are regulated by
the US National Electrical Code (NEC). An electrical conduit is made of
metal, plastic, fiber or fired clay. Most conduit is rigid, but it can be flexible
as well.
Types of Non-metallic Conduit
There are different types that are suitable for different applications. These
include:
Rigid Non-metallic Conduit (RNC): This is a non-metallic, unthreaded,
smooth walled tubing. It has been used for several years in the United
States, Canada, and Europe but has been under scrutiny for years due to
the fact that it is made of combustible materials.
http://www.pvccorrugatedpipe.com/Rigid-Nonmetallic-Conduit-RNMC-products.html
Electrical Non-metallic Tubing (ENT): This is a thin-walled corrugated
tubing that is moisture resistant and flame retardant. It is pliable and can
be bent by hand. Installation is easy due to its flexible properties. It is not
threaded due to its corrugated shape, although some fittings may be. ENTs
are usually light blue in color. They are pliable corrugated raceways made
from non-metallic material that is resistant to chemicals, moisture and
flames. Certain fittings are designed specifically to be used with ENTs, but
regular PVC fittings can also be used with solvent welding. They are easy to
install, without the need for any special equipment, though the
environments they are rated for are limited. ENTs can only be used indoors,
in areas where they will not be exposed to physical damage, hazardous
conditions, temperatures over 50°C and the conductors do not carry over
600 volts.
7
http://www.pvccorrugatedpipe.com/Rigid-Nonmetallic-Conduit-RNMC-products.html
Liquid-tight Flexible Non-metallic Conduit (LFNC): this refers to several
types of flame resistant non-metallic tubing. It is recommended as a raceway
for the installation of approved conductors with a nominal rating of 600V or
less for non-hazardous locations. Interior surfaces can be smooth or
corrugated.
LFNC-B Conduits: are also generally used in short sections towards the end
of a conduit. They have a seamless, smooth inner wall surface with integral
reinforcement and the exterior is waterproof, resistant to sunlight and dust.
Since they can be buried, encased in concrete and used in wet locations,
LFNC-B conduits are an excellent choice for indoor and outdoor
applications, both exposed and concealed. There are a few drawbacks
though, one of which is they are not suitable for housing conductors
carrying over 600 volts. Additionally, they are susceptible to physical
damage and a separate equipment grounding conductor will need to be
installed if needed.
8
http://www.pvccorrugatedpipe.com/Rigid-Nonmetallic-Conduit-RNMC-products.html
Polyvinyl Chloride Conduits (PVC) – PVC conduits are available in both
Schedule 40 and 80, which are basically ratios of the thickness of the wall to
its outer diameter. Both have the same outer diameter, which means a
Schedule 40 conduit will have a thinner wall, so it is not permitted for
installations where the conduit will be exposed to physical stresses. Most
commonly, the sections have one belled end and can be joined together, or
to fittings using solvent welding. PVC conduits are rated for almost any
application, especially since they are flame retardant, resistant to sunlight
and very affordable. However, they cannot be used in hazardous locations,
as ground conductors or in locations where they are exposed to ambient
temperatures over 50°C.
•
•
•
PVC Conduit: this has been considered the lightest weight and lowest
cost when compared to other types of conduits. In North America, it is
available in three different wall thicknesses. The thin wall variety is
suitable only for embedded use in concrete, while heavier grades are
suitable for direct burial and exposed work. The various fittings made
for metal conduit are also available in PVC form.
PVC conduit is heated and bent in the field using special tools. These
include joint to fittings that are made with slip-on solvent welded
connections. These set rapidly after assembly and attain full strength
in about one day. Since the slip fit sections do not need to be rotated
during assembly, the special union fitting used with threaded conduit
is not required. Because PVC conduit has a higher coefficient of
thermal expansions that other types of conduit, it must be mounted to
allow expansion and contraction.
When installing PVC underground in multiple or parallel run
configurations, proper methods should be executed to avoid
deformation when heated, due to the mutual heating effect of densely
packed cables.
9
http://www.pvccorrugatedpipe.com/Rigid-Nonmetallic-Conduit-RNMC-products.html
Fiberglass Reinforced Epoxy (FRE): Also known as reinforced
thermosetting resin conduit (RTRC) or fiberglass conduit, this is a
lightweight conduit as compared to a metallic conduit and also results in
lower labor costs and, at times, lower labor costs. It can be used in a
number of outdoor and indoor applications. It is available in multiple wall
thicknesses and has a support distance that is very similar to steel. For
specialty applications, including subway tunnels and station, zero halogen
versions are available which meet NFPA 130 requirements in the U.S. A
bonding conductor may be available for grounding. Joints are epoxy glued
which requires a bit of extra installation labor time while waiting for them to
set. The conduit may not be bent in the field and appropriate fittings must
be used to change directions.
http://www.pvccorrugatedpipe.com/Rigid-Nonmetallic-Conduit-RNMC-products.html
Electrical Conduits Fittings
Electrical conduits are metal, plastic or fiber pipes designed to protect
electrical cables and wires. They’re used in just about every residential and
commercial establishment, especially for wiring that is either exposed, or
fitted outdoors. Since they are essentially a safety feature, you should select
the material, size and fittings based on the environment of the installation
and the type of wiring it’ll be housing.
Types of Fittings
Section 110-3 of the NEC requires all the components to be listed and
labelled, so all listed parts meet certain construction and performance
requirements. However, the Code does not specify the material used for the
fittings, of which there are several. This will be determined by availability,
design considerations or personal preference. If you’re unsure about how the
conditions will affect the fittings, you can contact a manufacturer with
details of your application, consult a local distributor, or get an engineering
recommendation.
10
Conduit Bodies – These are tubular units with openings at each end for
admitting conduits, and providing access to the wires. There are quite a few
designs and you’ll find conduit bodies that connect two conduits in a
straight line, create 90° bends and join two different types or sizes of
conduit. Even the access point for the wires can either be exposed, or have a
cover with screws. Since conduit bodies can perform such a wide range of
functions, and some are also intended to be used as pull-boxes, they are
marked with the purposes they are rated to serve, as well as the internal
volume.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
Bends – To save time, equipment and labor costs, you can tackle changes in
the direction of a conduit with pre-fabricated bends. Commonly called
‘factory bends’ or ‘elbows’, they are available in a variety of lengths and
curvatures, and according to NEC requirements, you can bend certain
tubing’s by hand, using a mechanical bender, or a hydraulic bender for
larger ones. However, an installation may require a lot of bends, and
bending conduits on location might damage them or reduce the internal
diameter. Even with the use of factory bends, the NEC does restrict the
number of bends you can have between pull boxes to a maximum of 360°,
including offsets at the box or enclosure.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
Coupling – Conduit couplings are essential for almost any coupling system,
for securely linking together lengths of conduit and attaching site-fabricated
bends. Even though PVC conduits with a belled side can be linked without
couplings, they would still be needed for sections where the conduit has
been cut to size. Couplings are available in a variety of sizes and some of
them, like rigid conduit couplings, are threaded on the inside. However,
when the conduit is passing through a wall or making some other transition,
consider using a conduit body instead. Even for the first sections of conduit
entering or leaving the box or enclosure, use pull boxes or bodies so the
conductors can easily be retracted if the enclosure needs to be removed.
11
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
Bushings and Locknuts – Bushings create a smooth entry point to conduits
without any sharp edges, protecting the conductors from damage during
wire pulls. They are also extremely important when the conduit system
enters an enclosure or bus box. A bushing is installed on the inside of the
box opening and threaded into the conduit end, separating the conductors
from the edges of both the opening and the conduit end. Locknuts are
threaded on the inside, with teeth on one surface or both, which grip the
surface. They installed on both sides of the opening to ensure that both the
conduit and bushing are held firmly in place. If the locknut has teeth on
only one side, that side should face the box.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
Unions – Conduits often run along areas where space is constrained and
couplings are difficult to install. Apart from that, sections might at some
point get damaged, which is where unions are very useful. They have two
separate heads and a locking mechanism which can connect two pieces of
conduit together, even if they can’t be physically turned. Unions are
available in different configurations with male and female heads, or a
combination of both. The heads can be fit on each individual conduit end
and secured together, usually with a surface nut that slips over the two
parts and locks them together.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
12
Nipples and Hubs – Nipples can save time and money when a conduit is
needed between enclosures that are placed closed to each other, or for short
runs where field-threading the ends of a conduit is difficult. Like
prefabricated bends, nipples are threaded on both ends and can be installed
quickly and easily. As per the NEC, a nipple cannot exceed 24 inches in
length, beyond which it is considered a raceway and can only be used for
three current carrying conductors. Hubs are used to connect conduits to
bus boxes or enclosures that don’t have a factory-threaded entry.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
Reducers and Reducing Washers – A reducer is a special kind of
combination coupling that allows you to connect raceways of one trade size
to larger or smaller ones. Although it’s generally better to use a pull box,
reducers are handy for areas that have limited space. Reducing washers, or
threaded reducers, are similar to hubs, except both the inner and outer
surfaces are threaded. They are used to connect conduits to enclosure or
box openings that have a larger diameter, with locknuts on both sides to
fasten them in place.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
13
Straps and Clamps – Long runs of conduit and tubing require additional
support to keep them from sagging or breaking under their own weight.
Straps are used to mount the conduit to ceilings or walls using a screws or
bolts. To fasten conduit runs to fixed structures, like beams, hangers or
unis rut channels, the conduit is supported using clamps. For most
installations, the NEC specifies the maximum length of unsupported RMC
and EMT running in a straight line as 10 feet, and within three or five feet of
a box. For liquid tight flexible conduits, this reduces to every 4.5 feet of
conduit length and within 12 inches of a box or enclosure.
https://www.dfliq.net/electrical-materials-products/electrical-conduit-fittings/
Installation of Conduit Fittings
Conduit fittings shall be either of the screwed type, which are threaded for
connection to heavy-gauge conduits, or of the plain non-screwed type which
are primarily designed for use with non-screwed light gauge conduit.
Connectors
Joining Conduit with Electrical Boxes
https://www.ny-engineers.com/blog/electrical-fittings-for-metallic-conduit
14
Connectors are used to join metallic conduit with pull boxes, junction boxes
and other electrical enclosures. Metallic boxes typically come with knockout
holes, which are designed to insert connectors. The connector attaches to
the electrical box with a thread and lock-nut, while conduit is attached with
similar methods as those used for connectors:
•
•
•
For conduit types EMT, IMC and RMC, there are both set-screw and
compression connectors.
Conduit types FMC and LFMC use a special type of screw-in
connector that has a compression locknut.
All-purpose connectors use a pair of screws to adjust a metallic grip,
and they can be used with flexible conduit of smaller diameters, as
well as armored and sheathed cable.
Couplings.
These allow you to join conduit “sticks” together for a long straight run and
join site-fabricated bends to conduit. However, consider using a conduit
body where conduit passes through a wall or makes some other transition. If
you aren't near a bend, use a conduit body instead of a coupling at the first
conduit joint on the way into an enclosure and the first joint on the way out.
This allows retraction of the conductors if someone needs to remove the
enclosure. If a bend is nearby, use a pull elbow instead of a conduit body.
Bushings.
These provide you with a smooth, rounded conduit entry to protect the
conductors during wire pulls. Bushings are extremely important when you
are transitioning from the conduit system into an enclosure — especially a
bus box.
15
Bushing
Locknuts.
Any time a fitting enters a box, secure it with a locknut. If you use a nut
that has teeth facing only one side, be sure to install it with the teeth biting
into the box.
Locknuts
Service entrance heads and fittings.
You need to use these special fittings when transitioning overhead and
underground services.
16
Grounding fittings
Their purpose is to allow you to “jumper” around grounding path
discontinuities (or, potential discontinuities) in the conduit system. They
provide a continuous path to ground, even if you break the conduit. In any
conduit system, it's a good idea to install these wherever a crew may need to
break a conduit run for maintenance, troubleshooting, repair, or any other
foreseeable reasons.
https://www.bptfittings.com/resources/bridgeports-ground-rod-clamps-video/
Straps and Clamps: Attaching Conduit to Fixed Surfaces
Conduit Strap
Straps are used to fix conduit to surfaces. They have a U-shaped body that
allows them to clip around the conduit, and have one or two extensions with
holes for screws. Since conduit comes in a wide range of diameters,
normally ranging from ½” to 6”, straps are also available in the
corresponding sizes.
17
Strut clamps achieve a similar purpose, fixing conduit to surfaces, but the
design differs. A c-shaped strut is connected to a surface with screws, and
the clamps are then inserted into the strut, held in place by hook-shaped
legs. Each clamp is made of two identical halves that are joined with a screw
at their intersection, holding conduit in place.
Strut Clamp
When dealing with a single conduit run, straps are the most practical
solution. However, strut clamps are very useful when there are parallel
conduit runs, since the same strut segment can hold several clamps.
Elbows: Conduit Direction Change
Elbows are short conduit segments that are manufactured with a specified
turn angle, typically 90° or 45°. Being conduit themselves, they are normally
connected to straight conduit runs by using couplings - threaded, set-screw
or compression. Just keep in mind that threaded elbows required threaded
couplings, otherwise there is choice between set-screw and compression.
Elbow
Metallic conduit can be bent, so elbows may be avoided in many cases. EMT
of smaller diameters tends to be easy to bend, so elbows are rarely needed.
The difficulty of bending increases as conduit diameter becomes larger, or if
you are dealing with the more rigid types: IMC and RMC. A hand bender is
generally useful for EMT of small diameter.
18
Pull elbows
A pull elbow is a combination conduit elbow and conduit body. It allows you
access to the conductors at a point where you are changing directions.
Conduit Bodies: Combined Pull Box and Direction Change
https://www.ny-engineers.com/blog/electrical-fittings-for-metallic-conduit
Conduit bodies are among the most versatile and useful electrical fittings,
since they can be opened to serve as a pull box, while allowing a change of
direction if needed. There are also T-shaped conduit boxes with two
openings along the same axis, plus another opening at a 90° angle in case
two circuits must run in different directions. Electrical engineers can specify
conduit bodies to eliminate junction boxes in close proximity with bent
turns or elbows, since conduit bodies can perform the function of both.
19
Let Us Practice
ACTIVITY 1.1:
Multiple Choices:
1. Fittings that is essential for almost any coupling system, for securely
linking together lengths of conduit and attaching site-fabricated
bends.
a. Drains
b. coupling
c. unions
d. locknuts
2. The most versatile and useful electrical fittings
a. conduit body
b. nipples and hubs c. unions
d. reducers
3. They have two separate heads and a locking mechanism which can
connect two pieces of conduit together, even if they can’t be physically
turned.
a. Unions
b. bushing
c. drains
d. nipple and hubs
4. A kind of combination coupling that allows you to connect raceways of
one trade size to larger or smaller ones.
a. drains
b. nipples and hubs c. unions
d. reducers
5. These are used to mount the conduit to ceilings or walls using a
screws or bolts.
a. drains
b. coupling
c. unions
d. straps and clamps
6. These fittings cannot exceed 24 inches in length, beyond which it is
considered a raceway and can only be used for three current carrying
conductors.
a. bushing
b. nipples and hubs c. unions
d. reducers
7. A fitting that create a smooth entry point to conduits without any
sharp edges, protecting the conductors from damage during wire pulls
a. unions
b. bushing
c. drains
d. nipple and hubs
8. A type of fittings that help prevent drips and water-logging in the
conduit runs.
a. drains
b. coupling
c. unions
d. straps and clamps
9. It is used in joining conduit to conduit.
a. Reducers
b. hubs
c. straps
d. coupling
10.
A U-shaped body that allows them to
clip around the conduit, and have one or two extensions with holes
for screws.
a. drains
b. straps and clamps
c. unions
d. coupling
11. These are used to join conduit with pull boxes, junction boxes and
other electrical enclosures.
a. hubs
b. coupling
c. unions
d. locknuts and bushing
12. Bends in LFNC shall be made so that the conduit will not be damaged
and the internal diameter of the conduit will not be effectively reduced.
Bends can be made _____.
20
a. manually without auxiliary equipment
b. with bending equipment identified for the purpose
c. with any kind of conduit bending tool that will work
d. by the use of an open flame torch
12. Any channel designed to enclose and loosely hold electric conductors;
may be of metal or of an insulating material; various types include rigid
conduit, flexible metallic conduit, nonmetallic conduit, metallic tubing,
under-floor raceways, cellular floor raceways, surface metal raceways,
structural raceways, wire ways and bus ways, and auxiliary gutters or
moldings.
a. raceways
b. wire track
c. racetrack
d. wire tubing
13. Electrical term “raceway” applied to:
a. a channel system in carrying
b. where electric cars pass
c. conductor of heavy load energy
d. a group of transformer
14. Reducers can be used _____.
a. to connect conduits to enclosure or box that has larger opening.
b. in holding conduit
c. to protect conductors
d. in bending non-metallic conduits
15. Polyvinyl Chloride should not be used in__________.
a. Hazardous locations b. a temperature over 40 degrees Celsius
c. a ground buried conductor
d. a housing conductor
21
Let Us Practice More
Direction: Identify the tool that is being describe. Write your answer in on a
separate sheet of paper.
_____1. Conduit that are joint by epoxy glued which requires a bit of extra
installation labor time while waiting for them to set.
_____2. This has been considered the lightest weight and lowest cost when
compared to other types of conduits.
_____3. Conduits are an excellent choice
applications, both exposed and concealed.
for
indoor
and
outdoor
_____4. It can only be used indoors, in areas where they will not be exposed
to physical damage, hazardous conditions, temperatures over 50°C and the
conductors do not carry over 600 volts.
_____5. This is non-metallic, unthreaded, smooth walled tubing.
_____6. Pliable corrugated raceways made from non-metallic material that is
resistant to chemicals, moisture and flames.
_____7. Conduit that is heated and bent in the field using special tools.
_____8. A type of conduit may not be bent in the field and appropriate
fittings must be used to change directions.
_____9. Conduit that are rated for almost any application, especially since
they are flame retardant, resistant to sunlight and very affordable.
_____10. A raceway for the installation of approved conductors with a
nominal rating of 600V or less for non-hazardous locations.
22
Let Us Remember
A. Matching Type : Match Column A to column B. Write the letter of
your choice in the space provided before each number.
_____1.
a. nipple and hubs
b. drains
c. reducer
_____2.
d. conduit body
e. straps
f. bends
_____3.
g. bushing
h. locknut
_____4.
_____5.
_____6.
23
B. Give the meaning of each abbreviation.
1.
2.
3.
4.
5.
6.
FRE
RNC
PVC
NEC
LFNC
ENT
Let Us Assess
It’s time to try the fruit of our journey!
Direction: Identify the following. Write your answer on the space
provided for.
____________1. It a special kind of combination coupling that allows
you to connect raceways of one trade size to larger or smaller ones.
____________2. It creates a smooth entry point to conduits without any
sharp edges, protecting the conductors from damage during wire pulls.
____________3. These are essential for almost any coupling system, for
securely linking together lengths of conduit and attaching site-fabricated
bends.
____________4. A tubular unit with openings at each end for admitting
conduits, and providing access to the wires.
____________5. Bending conduit can be done manually, using a
bending tool commonly called.
24
Let Us Reflect
Congratulations! Let us ponder to this thought!
Direction: Write your answer on the space provided.
Do we have to follow the National Electric
Code for following the standards in using
nonmetallic conduit? Why?
____________________________________________
____________________________________________
____________________________________________
____________________________________________
25
1. Fiberglass Reinforced
Epoxy
2. Rigid Non-metallic
Conduit
3. Polyvinyl Chloride
4. National Electric Code
5. Liquid-tight Flexible
Non-metallic Conduit
6. Electrical Non-metallic
Tubing
26
Reducer
Bushing
Elbow
Conduit body
hickey
1.
2.
3.
4.
5.
6.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
C
E
G
D
F
A
FRE
PVC
LFNC-B
ENT
RNC
ENT
PVC
FRE
PVC
LFNC
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
1.
2.
3.
4.
5.
B
D
D
D
B
B
A
D
B
D
A
A
A
A
A
Answer key to Activities
References
•
•
•
•
https://blog.usesi.com/2018/06/03/electrical-supply-non-metallicconduits/
https://www.dfliq.net/electrical-materials-products/electricalconduit-fittings/
https://www.heritageplastics.com/pvc-electrical-conduit/
https://www.supplyhouse.com/Electrical-Fittings-20580000
For inquiries or feedback, please write or call:
Department of Education – Division of Tagum City
Office Address:
Energy Park, Apokon, Tagum City, 8100
Telefax:
(084) 216-3504
E-mail Address:
tagum.city@deped.gov.ph