1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Marat540 [252]
3 years ago
15

Where conventional relays, contactors and switches, which have arcing contacts, are installed in Class I, Division 1 and 2 locat

ions, they must be enclosed in ? .
Physics
1 answer:
solmaris [256]3 years ago
7 0

Answer:

They must be enclosed in explosion proof housing or general-purpose housing (as per NEC Regulations)

Explanation:

It is important to know what are Class I, Division 1 and 2 locations.

Class I: includes those industries or places where flammable gases exists and there are chances of explosions.

Division 1: Those places where hazard can happen under normal operating conditions

Division 2: Those places where hazard can happen under abnormal conditions.

The conventional relays, contactors and switches cause arcing when they operate and this is a completely normal phenomenon but with respect to these categories, it is very dangerous to operate such electrical devices without any precaution.

Therefore industries are required by the regulatory authorities to install  explosion proof housing to enclose conventional relays, contactors and switches to avoid any explosion or hazard. General-purpose housing can also be used given that it follows the regulations provided by the NEC or any other regulatory authority.

You might be interested in
Jacki evaluated the expression below. 2 cubed (3 minus 1) + 4 (8 minus 12) = 2 cubed (2) + 4 (4) = 8 (2) + 16 = 16 + 16 = 32. Wh
Naddika [18.5K]

Answer:

Her error was that she did not subtract 12 from 8 correctly

Explanation:

Jackie did 8-12 instead of 12-8

8 0
3 years ago
Critical angle of glass is 42 .what does it mean?​
elena55 [62]

Answer:

i think..its fraction that its have multiple fractions on it..if you minus the 397 000-355 it should be 381+ so i say if you get the 5 multiply it by 9!! so you will get it!

Explanation:

HOPE IT HELPS!!

6 0
3 years ago
Which equation correctly relates mechanical energy, thermal energy and total of energy when there is friction present in the sys
agasfer [191]

Answer:

E total = ME + E thermal

Explanation:

APEX

4 0
3 years ago
3. When a person is outside of the system and they add energy to the
NISA [10]

Answer:

We show added energy to a system as +Q or -W

Explanation:

The first law of thermodynamics states that, in an isolated system, energy can neither be created nor be destroyed;

Energy is added to the internal energy of a system as either work energy or heat energy as follows;

ΔU = Q - W

Therefore, when energy is added as heat energy to a system, we show the energy as positive Q (+Q), when energy is added to the system in the form of work, we show the energy as minus W (-W).

5 0
3 years ago
Every year _______ species go extinct.<br> a. 3<br> b. 72<br> c. 1000<br> d. 20000
Tems11 [23]
Well, the thing is: we don't really know, as we don't even know how many species there are on earth.

If we take a look at the estimates of <span>World Wide Fund for Nature, an organization that works toward combating species extinction, their estimates vary from 200 to 100 000 - but a probable number is 20 000 (d). </span>
<span />
7 0
3 years ago
Read 2 more answers
Other questions:
  • 5. A backpack weighs 9.2 newtons and has a mass of 5 kg on the moon. What is the
    5·1 answer
  • A xenon arc lamp is covered with an interference filter that only transmits light of 400-nm wavelength. When the transmitted lig
    10·2 answers
  • Using the word “more” to mean “I want another cookie” is an example of a( n):
    5·1 answer
  • How much heat is needed to raise the temperature of 8grams of water by 19°C
    9·1 answer
  • 1) An object with a height of 36 cm is placed 2.1 m in front of a concave mirror with a focal length of 0.50 m. a) Determine the
    13·1 answer
  • The number of protons in an atom is that element’s __________________ number.<br> PLEASE HELP
    14·1 answer
  • What are the units for momentum?<br><br> Kg<br><br> Newtons<br><br> m/s<br><br> kg·m/s
    8·2 answers
  • What creates the changes in step 1,2,3 of the nitrogen cycle
    9·1 answer
  • What does fissure and conduit have in common?
    15·1 answer
  • Two people are trying to pull a 5-kilogram block in opposite directions. The first person pulls to the right with a force of 25
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!