Basics Flashcards
Describe the basic wire types used here.
Teck Cable (armoured).
Fiber cable.
Cab tire (or flexible cable).
Seal/liquid tight (armoured like teck but empty)
BX
In a socket set, there are two sets of every size socket. Why?
One side is for the bigger socket. The other is for the smaller one.
A half inch nut pertains to which diameter?
The internal.
How do you open a cabinet that has its circuit breaker turned on?
By shifting the screw with a flathead left or right, while simultaneously pulling the door outwards (after loosening the door screws).
In the newer CB’s, the screw is small and below the handle. In the older ones, the screw is bigger and atop the handle.
Does the control power of a bucket need the circuit breaker turned on?
Yes. In usual cases, the higher voltage line side goes through a control transformer, which then feeds the control circuit (as discussed in class).
In a hand off auto switch, the “on” setting is what?
If in a HOA, it says on off auto, the on is the hand option.
Where are the do not use tags? Not the verification, not the lockout tags.
They’re in the same box where the lockout and verification tags are.
What is the new verification process?
A journeyman locks out what is requested by the foreman. The verification tag is placed upon the lockout. The journeyman uses his own lock.
The journeyman and foreman both then sign the logbook.
What is harder to drill through? Stainless steel or aluminum?
Stainless.
If trying to put a self tapping screw through a stainless steel backplane, should you use the “drill” mode on a drill or the “impact” mode?
Drill; the beginning of the tapper is technically like a drill bit.
What tool acts as a very good ruler/measuring device?
A level. You can use it to draw a straight line in chunks from top to bottom.
How to test a diode in either direction with a voltmeter?
The black lead pushes out electrons. The red lead pushes out holes. Test ohmic value in one direction, and then, switch the lead positions (ie if black was on side a of diode and red on side b, switch so red is now on side a and black on side b).
For mounting dinrail on a black pane, what should you use for material?
Drilling and then tapping and using a bolt is best, but tech screws or tappers are also acceptable.
If there are no hole slots uncovered in a din rail for fastening, what can you do?
Take out a terminal block or device, fasten behind the device or block, and reinstall the component taken out.
Line side is left or top side of a contact set for sure. But the circuit breakers, how are they oriented?
Up to the installer. I install them so I can read amperage when tilting head to the right.
Is it a big deal if panduit sizes are different in a cabinet?
No
Are endplates very important?
Yes. Without end plates, metal is exposed in terminal blocks.
End stops don’t function that way. End stops just act as added reinforcing so things don’t drop vertically on dinrail, or they act as a division.
Where are breakers installed in a circuit, if , for example, you have an incoming power supply to a PS transformer to a dc device?
They’re installed before every device. So they’d be before the original
Incoming feed, before the power supply transformer, and then before the dc device, downstream from the PS (ps here means the device which changes incoming ac to output dc).
What connectors are used in seal tight?
The seal tight connectors which are either metallic, or non metallic and look like strain reliefs used for cab tire.
In a cabinet, which colours, for single conductors, denote ac vs dc?
Red is usually ac. Blue is dc.
If you have watts on a device and volts, how do you figure out amps?
You divide the watts by voltage.
What is the maximum breaker size for #14 wire?
15A
How to determine which size wire to use on a circuit, and which size breaker?
Add up the ampacities of the devices in the circuit. That will help determine the conductor size (via table 2 in code) and the circuit breaker size (find the correct table to use).
Commonly, the wire and cb is rated for 125% of the amps of the circuit.
Which spray is used to lubrucate pull cords?
Loctite’s silver grade anti seize lubricant
What is the interface on a vfd called?
The HIM
How do you ensure good stranded connection under a screw?
By twisting wires by hand first
What is electrical tape rated up to?
600 volts.
How do you perform a crimp?
Select the right dye. Then, position it around what is to be crimped. Then, crimp down.
Note for grounds, may use c clamp, like we did when crimping to the rebar and fence.
Note: with the automatic crimper, if the right dye isn’t available, can go smaller, but not bigger, UNLESS you fold the wire over itself to make it bigger. If going smaller, can get one or two strands only if foreman allows.
If the wires are connected red black blue In a cell, from which way are you looking?
From the front of the cell.
What is the basic functioning of a solenoid?
A coil is energized, attracting or detracting the plunger, allowing or stopping the flow of pressure in the form of oil, gas, air, etc.
What’s the basic functioning of a relay?
A coil is energized or de energized. When energized, the contacts on the relay switch their positions from closed to open or open to closed.
What is the same as traverse?
Long travel
What is a stake on?
Stak on is the name brand for those crimps for wires where the lug is a ring or similar structure.
What’s a grounding bushing?
It has a terminal screw for the ground attached to it.
An Ethernet cable has a cable with 4 pair, #24 gauge.
What would the right denomination for a cable with 4-4 pairs be?
4 x 4-pair #24
