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New terms used
New terms used
A stove element is a circular heating device converting electric energy into heat to cook.
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Types of stove elements
Coiled heating elements: These are found in the cooktop of electric stoves and are exposed on the surface.
Radiant heating use ceramic glass surface to heat food.
Oven elements are found in electric and convection cookers ovens and transfer heat.
How they work
Electric current passes into a resistor in a heating element, which makes heat--a process called Joule heating.
The heat element glows red if it heats up as the filament is a resistor and is hot.
A multi-meter is
A multi-meter is
A GW Instek is a modern power meter measuring power, voltage, current, frequency and power factor simultaneously.
An ohmmeter is a
a 3-way switch
Ohm's Law-With Gwinstek-1
Ohm's Law-With Gwinstek-1
[1], [2]
2 switches are used to control lights in a stairwell, a switch at the top and bottom of the stairs.
The type of switch to control a light from two location is a 3-way switch.
Testing a 3-way switch with an ohmeter (upward switch)
Testing a 3-way switch with an ohmeter (upward switch)
We often start at the bottom left if it has a terminal and use the other lead in clockwise around the switch.
Here, with a upward switch, black lead is one the left side and red lead, on the other side.
As the ohmeter's needle didn't move, the 2 screws have no connections in between.
The 2 screws have no connection either.
The top right and bottom right terminals have connections as the ohmeter says 0 Ω.
Testing a 3-way switch with an ohmeter (downward switch)
Testing a 3-way switch with an ohmeter (downward switch)
Here, with an downward switch, the 2 terminals have no connection either.
These two terminals have a connection of 0 Ω, the same positions with an upward switch.
The black terminals are called the "common", which doens't need to be used with an ohmmeter each time on a 3-way switch. You find the common terminals.
3-way switch with light
3-way switch with light
With the light on, what if we flip Switch 1 to the opposite position?
This is a wiring for a 3-way switch, two with one light (L).
The middle light going between the 2 switches are the traveler wires.
With Switch 1 into the other direction, the current path stops and light is off.
What if we turn Switch 2 to the opposite position?
There's now a path to the light, which will go on.
EMT
EMT
The EMT (electro metallic tubbing) conduit is all interconnected to locking nuts that connect to all the tubing's metal pieces and the boxes to the electrical fuse panel.
Thought ground doesn't need to be between the boxes, we still need a device's ground wire (e.g. a switch or receptacles) to the back of the boxes.
Lab
Lab
Here are the 2-3 way switch and the lamp holder's locations.
Often as we use EMT, we run all wires per a conduct piece at one time.
In this case, as the tubing is a short distance in between, we run one wire at a time for simplicity, but don't actually do this as all wires will be jammed.
Instead pull all wires at once.
1. This station has the conduit going to all the right EMT.
Other station's conduits are one the left.
2. This arc vault breaker is removed from the breaker panel.
There are 2 screw terminals here.
The black wire goes to the brass screw and the white one goes to the silver screw.
3. The ground wire is either bare or green color, no other combination.
This case we use a black and white wire to feed the 3-way 4-way switch. This wire goes to the EMT.
Note: We marks off each step in blue in the diagram.
Rules to use EMT: The white wire only goes to the neutral bar, no other connections.
4. The ground wear is either bare copper or green insulated wire. This case uses green wires.
5. Next, connect the wires from he lives to the comnmon of the 1st switch.
This case uses a black wire from the conduit through octagon box down to the 1st switch then to the colored screw.
Then connected the neutral. The white wire rom the fuse panel goes hrough the 1st octagon into the 2nd octagon then to the lamp holder's silver screw.
6. Next, connect the 2nd (right) switch's common to the light.
This case used a black wire from the 2nd switch's black terminal up to the octagon box and the 2nd box, and to the lamp holder's brass color terminal.
7. Only 2 traveler wires to connect.
It doesn't matter if we took the wires from a switch on a wrong screw of the 2nd switch.
E.g. The 2-3 way switch has 2 empty screws still work even if mixed.
This case uses a blue lead on the left from a traveler screw up to the 1st octagon box to the middle box and to one of the traveler screws on the right.
But in the middle box, the wires are continued as a junction with a marette, as later we'll split for the 4-way switch, which make things easier.
8. The last traveler wire also gets a red wire from the left switch up to the continued with a juncion in the middle box with marrette, then to the last screw on the right switch.
Now with a high voltage glove turn on the light bulb in the lamp holder.
Any time we flip any switch, the light should go into the opposite state (if off, turns on--if on, turns off).
References
References
[1] Video Pt 1 - YT
[2] Video Pt 2 - YT
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