Carbon Arc Cutting (CAC– A) Flashcards

(64 cards)

1
Q

What type of eye protection must always be worn during carbon arc cutting

A

Safety glasses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what shade lens is recommended for CAC – A cutting at less than 500 Amps

A

12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

True or false? Gouging is a very loud process

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the most important thing in reducing the risk of electric shock when using CAC-A

A

Do not run cables through water, Keep electrodes and torches dry, and keep your gloves dry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What must you check before touching an electric shock victim

A

Make sure they are not still in contact of the circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Gouging can shoot sparks and molten metal up to?

A

6 m ( 20 ft)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do you not want to play spark shields too close to where you are working?

A

Sparks can bounce back and burn you

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Combustible materials should be moved how many metres away

A

15 m (50ft)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What type of electrode is used in CAC – A?

A

Carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of power source is generally used with CAC-A?

A

Constant current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many psi (kPa) is required for a gouging torch?

A

82-100 psi (551-689 kPa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A medium duty torch uses how many cubic feet per minute (cam) of compressed air?

A

25 cfm (700L/m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can CAC-A be used to do?

A

Cut, gouge, & wash a surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

True or false? CAC-A is used for removing weld defects

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or false? CAC-A can be used to cut most types of ferrous and nonferrous metals

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which polarity is recommended for carbon and low alloy steel?

A

DCEP (direct current electrode positive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Welding power sources used for CAC-A are recommended to have what percentage duty cycle?

A

100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the minimum recommended open circuit voltage of a CAC-A?

A

60 V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Machine gouging with an automatic electrode feeder is typically done with what power source?

A

Constant voltage CV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

True or false? DC electrodes can be used with AC power

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When electrode diameter goes up what does amperage requirements do?

A

Increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

To connect two power sources together you must ensure what?

A

Ensure they are connected in parallel, ensure to follow the manufactures directions, and ensure they are identical. 

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In CAC-A, what will insufficient air supply cause?

A

Carbon buildup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What gas can be used as an alternative to compressed air?

A

Nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Hoses and fittings for medium and heavy duty gouging must have an inside diameter of?
3/8 in (10mm)
26
What is the biggest difference between a SMAW and CAC-A electrode holder?
Air jet holes
27
Air jet holes are found?
Between the electrode and work peace
28
How many times should the electrode holder be examinated for wear and damage before use?
Daily
29
What size cable is commonly used for CAC-A?
#4/0
30
CAC-A Electrode holders contain an electrical cable and what?
Air supply hose
31
True or false? Working above a cable rated capacity can cause overheating?
True
32
The workplace lead must be connected where?
As close to the work area as possible
33
Who is responsible to ensure equipment is safe to use?
Employee
34
What does the copper coating on DC copper coated electrodes do?
Improves electrode life, improves heat dissipation, and maintains the electrode shape
35
DC copper coated electrodes come in size ranging from 5/32 in (4mm) to?
1in (25.4 mm)
36
Uncoated electrodes are mainly used for?
Demolition
37
AC copper coated electrodes contain?
Arc stabilizers
38
CAC-A Electrodes come in how many different shapes?
4
39
Jointed electrodes are designed to?
Be joined together
40
True or false? Flat electrodes are usually used to remove weld reinforcement or backing material.
True
41
Groove width is usually how many inches larger than the electrode diameter?
1/8 in (3.2mm)
42
1/4 in diameter DC electrodes require 200 to how many amps?
400 amps
43
You should replace an electrode when it gets down to how many millimetres or inches long?
50mm or 2 inches
44
True or false? CAC-A stubs should not be thrown on the floor as they can cause a slipping hazard?
True
45
Is most CAC-A cutting done manually or by machine?
Manually
46
What do most CAC-A cutting machines consist stuff?
Motorized carriage, power supply, and track
47
How do fully automatic machine controlled electrodes feed rate?
By Sensing arc voltage or amperage
48
Electrode angle for cutting is almost what degree to the base metal?
90°
49
CAC-A is typically done with a pushing or pulling technique?
Pushing
50
What type of cut does a steeper electrode angle produce?
Deeper
51
What type of groove will a straight up and down electrode produce?
V-Shaped
52
Slower travel speed will produce a groove that is?
Deeper
53
What is the indicator for correct travel speed?
A steady hissing sound
54
True or false? Higher current settings produce larger grooves.
True
55
What do you do if you do not have enough air supply?
Decrease travel speed
56
Electrode stick out should be?
4-6 in (101-152mm)
57
An electrode should be repositioned when it is how many inches from the torch?
1 1/2 - 2in ( 38-50mm)
58
How do you strike an arc with CAC-A?
By touching the electrode to the base metal momentarily
59
True or false? You want to avoid touching the electro to the base metal as it causes contamination
True
60
What do you want to ensure before starting to gouge?
air valve is opened all the way, air jets are positioned between the electrode and workplace, and the stick out is correct
61
True or false? Gouging can be done in all positions
True
62
Gouging in the vertical position is usually done in the uphill or downhill direction?
Downhill
63
What removes the molten metal from the groove?
The compressed air
64
How can Harden areas produced by CAC-A be removed?
By grinding