This is the one I use, and I use it for all my rabbit pens too. Been using these for years.
They are made for outside use.
I’m not as worried about water freezing because I will still be checking frequently enough. I’m more worried about a fire starting, or is that not really a concern here? Thanks!
I was really interested in that heated pet bowl as posted by
@sharrielee because I am looking for a backup to my
Little Giant metal base heater. Following that link for the heated pet bowl, the price is really great and the 8 reviews are very positive.
My concern is also potential fire hazard. Amazon.com also sells this same
heated pet bowl by Farm Innovations. With 4 out 5 stars after 479 reviews, it must be a good unit. However, I think you should pay attention to those reviews on Amazon.com that indicated failure of this heated bowl and how the heating element burned through the plastic base cover causing a potential fire hazard.
One gentleman indicated that he gave the unit a 5 star rating but downgraded it to 1 star:
"Dec 2016: was 5 stars. This bowl is now entering its 7th winter in the run of my chicken coop. It keeps the birds' water free from ice year round. Northern New England has been walloped with some really cold days this year, down to -11f and it keeps the ice and frost away. The wire around the cord has rusted and looks bad, but the bowl does its job without fail, providing maintenance free water to my chickens.
Update:March 2018. Downgraded to 1 Star now. The bowl failed, leaving a melted spot on the bowl and singe marks on the floor. I am very glad it didn’t start a fire, but now hesitate to buy again."
As I stated, I'm looking for a backup to my metal base heater. IF I were to consider this, or any other heated dog bowl with plastic housing for the heating element, I would be sure to put the heated bowl on a concrete block or some other non flamable substance. After reading the Amazon.com 1 star reviews for my Little Giant metal base heater, there are a number of the same fire hazard concerns. So I will be putting my metal base heater up on a concrete block too.
As to extension cords,
I would refer you to this chart I use:
What Load Can Each Gauge Wire Handle?
16-Gauge Cords: Any 16-gauge cord between 0 and 100 feet long will adequately handle tool loads up to 10 amps.
14-Gauge Cords: Any 14-gauge cord between 0 and 50 feet long will adequately handle loads between 10 and 15 amps.
12-Gauge Cords: If your tool load is between 10 and 15 amps and the length of the cord is 50 to 100 feet, you need a 12-gauge cord to safely power any tool.
The formula for watts is: Voltage x Amps = Watts
In the case of the 60 watt heated pet bowl:
Amps = Watts/Voltage which is 0.5Amps = 60watts/120volts
Clearly you only need 0.5 Amps to power the heated pet bowl, so even an inexpensive 16-gauge grounded outdoor cord at 100 feet would be more than adequate for that job. You would not need to buy the expensive heavier extension cords.
Furthermore, the
rule of thumb is: Because we use 120 volts as an electrical standard here in the USA, that means that every 600 watts equal 5 amps (120 x 5 = 600).
With that in mind, if you added additional power devices to your load on a cheaper 16-gauge 100 foot extension cord, you could probably get as much as 1200 watts for your devices. Obviously, a heavier cord can be used for more power hungry devices, but the only time I have needed to use my heavy 12-guage 100 foot extension cord was for using my electric circular saw cutting through some hard wood.
I apologize for the long post, but some of the information I was reading here on the thread did not ring true with what I was taught. So as I looked up the specs on this project, I copied and pasted the info I will be using as I decide on my backup system to my heated waterer. I hope this information will be helpful to others.