What is SPT-1 vs. SPT-2?

So, what is the difference between SPT-1 and SPT-2?

When shopping for Christmas light strings specifications you might have noticed are the SPT-1 and SPT-2 specifications.  You'll especially see these terms when shopping for C7 and C9 Christmas bulbs and cords.

This spec is simply an indicator of the thickness and durability of the insulation

Most of the time, Christmas light cords don't list this as a spec and in those cases, you can almost always assume that the cord is SPT-1 which is a standard commercial grade cord.

A thicker, more durable insulation is  SPT-2 rated insulation.  We started carrying the cord with this thicker insulation a few years ago to meet the needs of commercial customers. We now carry a wide variety of wire colors and socket spacings with SPT-2 rating.

What current is SPT-1 or SPT-2 rated for?

There is some misinformation on the internet that a higher SPT rating indicates that the wire can take a higher current - this argument is used to say that SPT-1 can't carry the same 10 amps as the SPT-2 version.  This is not accurate information.  The amount of current a cable or wire is rated for is strictly a function of the copper used for that cord.

Please remember with all things electrical that if you have a serious question about what wire to choose and how it will work in your situation that a Master Electrician is the first person to consult. I suggest that you consult with one on any project where cutting of 1000 foot spools to custom lengths is involved - especially at commercial/retail installations.

Should I choose SPT-1 or SPT-2?

For most applications, where lights are up 2-3 months a year, in most environmental conditions SPT-1 is perfectly suitable and since it is a hardy cable at the most reasonable price it is generally the most popular choice of installers, as a rule of thumb.  

SPT-2 is best used where environmental conditions are more extreme or for longer-term installation.

Keep in mind that most companies, including Christmas Light Source,  provide a 90-day warranty for normal, seasonal use of lighting products. The ultimate lifespan of all Christmas lights depends on sun, wind, rain and general environmental exposure. 

The decision to use SPT-1 or SPT-2 will be a factor of your project, environment and budget.

Choose wisely.

Oh, and as a tip, make sure that the plugs you purchase are rated for either SPT-1 or SPT-2 as the second variety has to be designed to fit the larger insulation.

 Related terms: C9 C7 Cords Cord 18 AWG Insulation

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Shipping Policy

Shipping exception notice: We are closed for 4th of July week. Orders placed now will ship the week of July 11, 2022.

We are currently shipping Monday - Thursday with most orders shipping the same or next business/shipping day. 

Once an order is placed it is put immediately into a shipping queue, this means we cannot cancel or modify your order once completed. If you have ordered incorrectly, you can return any uninstalled items that have been shipped to you. See our Shipping, Warranty, and Returns page for more information.

To Prevent Delays

Please double-check the address. Include a correct phone number to be used only if there is an issue with the order.  We do not ship to PO Boxes. Orders with PO Box addressing will be delayed while the customer is contacted and the address is corrected.

To prevent delays: Confirm the wire color of all items. Confirm that bulbs and cords match (for example, C7 with C7, C9 with C9, E12 bulb with E12 cord). Confirm SPT rating of cords and plugs match.

Delivery Timeframe Notices Regarding Air Orders (Excluding Holidays)

Orders placed via ground service should arrive in 1-5 business days depending on your zip code. This estimate does not include weekends or major Holidays.  

2-Day air orders shipped on Thursday do not arrive Saturday but should arrive the following Monday. Next-Day orders shipped on Friday do not arrive Saturday but should arrive the following Monday. No orders are delivered on the weekend and the weekend does not count as days in transit.

Due to these unprecedented times and high shipping volumes, UPS and FedEx do not guarantee the day and time of any method of shipping, including 2-Day and Next Day Air Service.

To ensure prompt shipping verify that your order is correct. Please do the following checks:

1. Confirm bulb bases and cord sockets match. 
2. Confirm 18 AWG wire SPT rating matches the SPT rating of plugs.
3. For bulk C7/C9 bulbs and cords orders, don't forget gilbert plugs, if required.
4. Double-check the wire color on all strings lights.