This tutorial is based on one created by Landolights.com, Wolfstone Technology Pages and our Minions Web products.
It covers common components, assembly and alterations
to create your own customized cords and how to assemble them.
Holiday enthusiasts, haunted houses and amusement venues have many obstacles to overcome.
One of the biggest headaches to cope with as part of your display, is providing
power for lighting and accessories in a logical and sensible manner.
Custom cordage for your display, whether it is one to length cord, an LED lighting distribution harness or logical power supplies for much of your display, has distinct advantages over assemblages of store bought extension cords, triple taps, light stakes and power strips:
They can be made to exact dimensions, eliminating unsightly 'snake pits' (coils of extra extension cords lengths) while reducing trip hazards.
They have reduced bulk compared to store bought cord-sets, saving valuable storage space.
Typically cost less than or equal to store bought assemblies of extension cords, adapters, triple taps, light stakes and power strips while being safer overall.
While typically used for indoor applications, zip cord (commonly refered to as appliance or lamp cord) can be used safely outdoors if you observe some simple safety precautions.
These same precautions should be used for ALL your power supply lines to the various scenes, sets and lighing clusters:
Extension cord style power lines should only be used temporarily outdoors.
When the season is over they must be stored INSIDE.
Each year, thoroughly inspect each line for cracks, frayed jackets, and brittle or missing insulation.
If you identify problems, take the line out of service until it repaired or replaced.
Never overload the cords.Don't overload your cord-sets.
Always calculate the amperage utilized on any given line
to assure consumption to be 25% below the peak rating for the wire gage used.
Overloaded power cords can melt or catch fire.
Melted cords can expose live wires posing a shock hazard.
Self made Zip System cords are NOT protected by an inline fuse - you MUST exercise caution.
If you are unsure about the load, we offer an inexpensive inline electricity usage testing meter, or you can get a 'Kill-A-Watt' device at many big box hardware stores, or conveniently we offer this online calculator for your use:
Ohms Law Calculator
Enter any two known values and press "Calculate" to solve for the others.
For example, a 100 watt light bulb operating on 120 volts AC will have
144 ohms of resistance and will draw 0.833 Amps.
Enter 100 in the
Watts field and 120 in the Voltage field then click Calculate to find
the resistance and current.
Fields should be reset to 0 before each
Voltage (E) = Current (I) * Resistance (R)
Power (watts) = Current Squared (I^2) * Resistance (R)
Power = I*E = E^2 / R
Line voltage (residential and industrial) Electrical cords and devices used outdoors MUST be GFCI (Ground Fault Circuit Interrupter) protected.
The danger of electric shock is REAL!
Do NOT put you, your family or any visitor's life on the line by NOT using GFCI protected outlets.
Terminology, definitions and details
Also known as "applicance" or "lamp" cord is a pair of annealed, bunch stranded copper per UL 62 gauge wires in a THNN channeled plasticized jacket.
Zip cord is available in 12, 14, 16, 18, 20 gauge, though most often in 16-20 gauge.
The jacket or "insulation" has three thicknesses referred to as SPT, ranging from 1-3.
SPT stands for:
Stranded (vs. Solid core)
Parallel (Flat cable. vs. Twisted)
Thermoplastic (vs. Neoprene)
The number following SPT is the insulation thickness and NOT the conductor thickness:
1 = Light duty
2 = Medium duty
3 = Heavy duty (may be suitable for burial at low voltages)
SPT1 covers all rubber, parallel jacketed, two conductor light duty cord for pendant or portable use.
It has insulation values rated from 75V to 300V.
has similar properties as SPT-1, with heavier construction, with or without a third conductor for grounding purposes.
It has insulation values rated from 150V to 300V.
has similar properties as SPT-2, with heavier construction for refrigerators or room air conditioners.
It has insulation value of 300V.
Don't confuse the SPT number shown as the gauge (conductor size).
Notice there has been NO mention of wire thickness.
Most people confuse SPT-1 with 18AWG and SPT-2 with 16AWG, that is simply NOT true.
You can get almost any AWG in many different insulation types.
The conductor (composite copper wire inside the rubberized jacket) size is referred to as the wire's 'Gauge'.
Solid conductor wire is also gauged
with slightly different criteria regarding diameter and amperage carying capacity.
Solid conductors are not utilized in Zip cord wiring.
AWG, American Wire Gauge, or simply 'gauge' is the size of the actual conductor and the most important factor when it comes to how much current a wire can carry.
AWG standard numbering works Backwards - the smaller the gauge, the larger the conductor wire that can carry MORE current.
Examples of different zip cords that can be used for holiday displays:
Is it cost effective to make customized Zip cords vs. stock extension cords?
The short answer is possibly.
Depending on length and configuration, mass produced extension cords can be less expensive than single cords you could make yourself.
Wal-Mart negotiates better pricing on 10 MILLION feet of extension cords than you ever will, when buying 500 feet of zip cord.
The economics change when you create to size and 'multiple drop' cords (cords with more than 1 outlet along the length) and cord-sets in the 15-30 foot range.
When setting up a thunder & lightning (T&L) system or lighting a cemetery scene, you would piece together a number of existing cords, block, triple tap or power strips more extensions, and stake fixtures.
A T&L set up
can easily comprise 12 or more lights, fixtures, taps and several hundred feet of cordage in a 1/4 acre yard.
A cemetery scene with 10 tombstones will often have more than 100' of cords with 12-20 light fixtures in an area roughly 20 x 30 feet.
Commercially produced 16g SPT2 extension cords vary in cost from .10 to 1.00 per foot, in lengths from 6 -15 feet, and 12 light stakes at $6-$15.
If the average cost for a 10' cord is $3.00 (x15) and a light fixture is $7.00 (x12), you will spend $10 per light to have a moderately flexible lighting system roughly 150 ft in length for an expense of $129.00 or 10.75 per light or .86 cents per foot.
You will need to protect the open outlets on each cord end as well when considering the safety factor.
If constructed from contractor style 16/3 extension cords, you will have snake pits of wires, adapters, multi-tap connectors and/or power strips as well as the stake fixtures averaging $10 per 25' cord (x6), $7.00 per stake fixture(x12) , $3.00 per triple tap (x8), $6.00 per power strip (x3) for a cost of $188.00 or $15.67 per light or 1.25 per foot!
Compare this to the Zip Twist system.
Since you are using LEDs you can reduce the wire gauge to 18, or remain at 16 if you want to connect a prop or >= 1000 watt fog machine on line.
200' of 16g SPT2 wire costs $60.00 @ .30p/ft, 12 medium sockets @ $3.79 ($46), 12 washers @ .37 ($4), 12 Universal LED Stakes or Universal LED Mounts @ $3.79 ($46), 1 16g SPT2 snap on plug and 4 16g SPT2 snap on receptacles ($7.50) for a total cost of $157.00
or 13.08 per light or .79 per foot
Remember this is using 200 feet!
As will be shown shortly, you can place the Zip twist vampire style sockets anywhere along the zip cord length, as well as the receptacles.
You are not limited by each extension cord segment spacing.
The custom cord is made to the exact dimensions you need so there is snake pit, the light sockets are exactly wher eyou want them and can be relocated quickly, the outlets are exactly where you want them for proper hookup, and the entire assembly is much lighter, sturdier and easier to store than the equivalent 150 foot cord assembly of assorted components.
Proper gauge and insulation selection
You must determine how much load each custom Zip System cord can carry:
18AWG - 10 Amps MAX (or 1100 watts at 110 volts - approx (160) Minions Web 120 LED PAR38 bulbs)
16AWG - 13 Amps MAX (or 1430 watts at 110 volts - approx (210) Minions Web 120 LED PAR38 bulbs)
14AWG - 17 Amps MAX (or 1870 watts at 110 volts - approx (285) Minions Web 120 LED PAR38 bulbs)
You need to factor the length of the cord you will make.
The longer the cord, the greater the internal resistance.
This table indicates the wire gauge (thickness) required for a known length depending on the current drawn.
If you need to run more than 200 feet, it is recommended to have a certified electrician install a GFCI receptacle in an outdoor rated enclosure with properly rated direct burial or conduit encased wire (10AWG or 12AWG) close to where the power is needed.
The larger the AWG number, the thinner the wire, which translates to the less current that it can carry safely.
Where the chart suggests 16ga., and you don't have a 16ga. cord, go down to 14ga. - smaller number
but a larger size.
Zip system and extension cords are made of copper wire, whic is a good yet imperfect electrical conductor.
The thinner the wire, the greater the resistance per foot, which causes the wire to heat up.
The more current you draw through a cord, the more heat you get.
You should take into account bundling multiple cords together into a harness.
Multiple low-amperage draws bundled together acceptable, but may generate some radio interference.
Running multiple heavy load cords togethermay generate a lot of heat.
Bundling wires together can cause heat to build quickly, causing melted insulation, short circuits and possible fire as a result.
In cold climates where it snows, harnesses that generate snow melting heat should be split into 2 or more smaller harnesses.
Sockets, Plugs & Light Sockets
After selecting the approriately gauged and jacketing wire for your application, you will need like sized plugs, receptacles and lamp sockets.
It is not uncommon to hear Zip Twist system components referred to as "
vampire" sockets (or plugs).
These components have 2 small metal teeth that pierce the insulation to make the connection with the encased wire.
When ordering receptacles, lamp sockets and cord plugs, be sure you to correctly size each item for the wire you will be using.
Receptacles, lamp sockets and cord plugs are ordered by the size of the INSULATION being used, and the wire gauge.
The difference being the teeth of the components made for SPT1 and SPT2 have different size and spacing.
Since SPT2 has thicker insulation than SPT1, the teeth must be longer.
Using an SPT2 plug on SPT1 wire may cause the tooth pass further than the conductor middle, possibly passing completely through the other side.
Using an SPT1 plug on SPT2 wire will cause the teeth to not penetrate the insulation and underlying conductor far enough, resulting with the cord-set not working or it causing failure due to insufficient wire in contact with the teeth.
Always terminate each Zip System Cord assembly with a plug and a receptacle.
Never leave an assembly end without a termination.
The Zip Twist system is quick and easy to install.
There is no need to strip wires.
The receptacles can be adapted for use in the middle of a cord and lamp sockets can be placed in whatever location along a length of zip wire you need.
This allows you to have a cord-set that is the exact length you need, with outlets spaced exactly where you need them.
For example, our graveyard lighting is 120' of zip wire snaking through the graves with more than 20+ LED bulbs in medium zip twist lamp sockets, washers and universal LED stakes, with a mid-line receptacle roughly 70' down the run, to connect the front gate pillar zip twist assembly, all tied to 1 circuit.
have flame lights, the main suspended illuminated sign, spot lights uplighting the pillars, spots backlighting the gate cut out and a fog machine, all powered off one custom cord set created with outlets as needed.
Some outlets are immediately next to each other, with others up to 16 feet apart.
The description is to stress a point - DIY cords can be constructed to EXACTLY the dimensions you need.
We had done this with extension cords in stake fixtures in the past.
It was very difficult to organize, keep track of and store, in addition to the prayers we would have enough fallen leaves to hide the extension cord snake pits due to all the extraneous extension cords lengths.
The common components can be found on Minions Web and a number of assorted sources.
This list links to each item available via the online store within MinionsWeb.com
90% of what I have is 14G SPT3.
You can never have too much power capacity or too big a conductor.
Making a custom cord-set
Once you have your Zip System wire, vampire plugs and receptacles it is simple to make a cord-set.
Look closely at the zip wire, 1 strand will be marked in some way - usually the insulation is ribbed on one the the 2 conductors, but it may be a different color, have a stripe along the length, contain a different color conductor (white vs copper), or be marked with production numbers and specification details.
However - many wire have both a ribbing, ridge or stripe on
the common and have printing on the hot, so pay close attention.
The ribbed wire should be the NEUTRAL, and it's very important to respect that thought all your cord building.
Look at different appliance and lamp cords throughout your home, and you will see that the ridged insulation is always the neutral.
Measure the length of wire you need to make your particular cord.
It is prudent to give yourself at least 2 extra inches that will be lost in length under the plug and receptacle covers.
If you use controllers with the cords, account for extra length to route your cords.
Ccutting the zip cord ends square.
Seperate the two parts of the plug or receptacle to look at them closely.
It is a polarized device.
Electrical wiring should always be polarized, with common/neutral connection wired to like, and the hot (positive) connections are wired in the same manner, always together.
The neutral/common on polarized plugs is always the wider of the 2 blades.
Some manufacturers may mark the polarized blade.
Looking at the back of the plug, you will see 2 prongs that correspond to the neutral and hot blades of the plug or the wider slot on the receptacle.
The marked side of the zip cord goes over the prong of the polarized side.
Notice the small cavity on the inside end, which the zip cord end should be placed, then bent over the prongs to be as close to flush with the cavity top as possible.
The cavity may be divided, if so split the 2 conductors insulation by 1/4 of an inch.
Insert the cut wire end into the cavity at the head of the plug or receptacle.
Double check that the ribbed or indicated side of the cord (remember this is a polarized) is over the wider 'Common' or 'Neutral' vampire prong.
With your fingers, press the wire flat and flush to the top of the plug.
Slide the cover over the top of the plug.
Note that there are 2 different ends to the top, one has a small tab.
The end without the tab goes on first.
For this step we recomend the use of a pair of full size adjustable channel lock pliers, especially if you have weak fingers.
You will find it is quite difficult to slide the cover completely over the wire without tools.
Using the pair of pliers, use the upper jaw to hold the business side facing away from you, with the wire groove running towards the plier grips.
With the lower jaw on the cover end with locking nub, slide the 2 parts together with a smooth squeeze of the pliers, be sure the wire you are connecting is draping from the bottom gap.
Be careful not to don't damage the wire!
We will illustrate how to attach the 2 lamp socket styles we offer to construct customized light strings.
When you look at a lamp socket, you should look for the indication of polarity.
may see one side that says 'ribbed', or labeled contacts with '+' or '-', or a number of other indicators.
As we noted earlier, always place the wire into the socket so that the ribbed wire is on the same side to maintain polarity.
This is especially important when making light stringers for LED lighting, as many LED lights are not properly designed to deal with reversed polarity.
Making your own light strings facilitates whatever spacing you need for your lighting schemes.
Making a custom C7/C9 string
The first method is for
C7 and C9 snap on type bases and attaches in a similar manner as the plug and receptacle.
The major difference is locating polarity of the neutral side of the lamp socket.
Create a custom cord-set using the instructions above.
Each cord should begin and end with a male plug and female socket.
Bare wire ends are unsafe and unacceptable.
Look on the inside and flip side of the light socket to see which vampire tooth is connected to the center of the light socket.
Also pay attention to which is connected to the tab on the side of the socket.
Place the light socket on your work surface with the open end down, and the 'vampire' teeth up.
Identify the common side (ribbed) of your cord-set.
Line up the wire with on the rear of the socket so the common conductor will be pierced by the vampire tooth for the side contact of the socket.
The hot or positive unmarked conductor will sit over the center tooth.
Use your fingers to press the zip wire into place.
Insert the tabs of the light socket bottom into the corresponding holes in the socket base.
Press the bottom firmly into the base until the tabs snap, locking the zip cord into place.
Make sure both tabs have engaged.
You may also use a pair of slip-jaw pliers to seat the tabs fully.
Add sockets as needed, at the spacing you want. Remember that these light-sets are not protected with a fuse, and you could overload the cord if you place too many light sockets on your custom set. Always be sure to know your loads!
Making a custom Medium (E27) Twist Zip string
Making a twist zip string is surprisingly easy.
polarity is as simple as looking on the back side of the socket.
The teeth are color coded, brass for hot, white for common, as well as a plus sign and negative sign by each tooth.
Simply place the polarized (common, ridged) over the negative or white metal terminal.
but we are getting ahead of ourselves.....
With the proper polarity identified for the socket and cord, use a utility knife with a fresh blade to cut the insulation between the 2 sets of strands along the length of the zip cord where you would like to place a lamp socket, then place it on the base.
Once the zip cord is placed over the medium base twist lock hub in the proper polarity, twist the hub until it snaps closed, biting the vampire prongs into the zip cord.
If you find this very difficult to close you can use a piece of 120 grit sand paper to remove a small amount of the nubs in the hub.
You should only need to do a few swipes of the sand paper to close the hub easily.
Now, with your medium socket in place on the zip cord, take an LED bulb, a Zip Twist Washer Gasket, and one of the Minions Web Universal stakes or mounts, to creat an inline fixture.
First thread the stake or mount over the LED bulb end, followed by a washer, then sandwich the washer between the lamp socket and the stake or mount.
The assembly should be hand tightened
Once this is put assembled, you can easily place your light where ever it is needed.
If you need additional space between lamps, simple remove it from the location you placed it in a repeat the attachment elsewhere.
The mounts and stakes are made with a thermo-setting plastic and can be warmed with a hair dryer or heat gun on the stem to tweak the angle and rotation of the light.
The mount tabs can also be heat set to almost any shape you desire
Wear gloves to protect your fingers from the heat when heating the plastic.
Simply quench the warm plastic in water to quickly set a bend or curve.
Adding inline Receptacles
Want to add an outlet in the middle of a cord?
Using a zip receptacle, remove the cut-out at the end where you would normal teminate the cord.
This can be accomplished with a pair of diagonal wire cutters, or you can use a short hack saw blade to cut the side flush and bend the remaining part of the knock out free with a needle nose pliers.
Doing so will open a passage to let the zip wire pass straight through the receptacle block.
You must maintain polarity following the ribbed (common) line with the wide blade hole.