I have an Intermatic Model DT-17 programmable plug-in lam and appliance timer 15 amp and inductive 500 watts but no programming instructions. How can I reset the time I wish to have it turn our lights on??

Timex 12-881 timer has 3-prong outlet and is rated 15amp 1875 watts.

The timer melted because too much amperage was drawn across the connection and timer got hot.
Different things can cause this.
Phony rating, and/or mis-manufactured timer.
Defective timer.
If distiller has a motor, then it will draw more amps at start-up.
Timer is rated for incandescent light bulbs only.
Many timers say 1875 watts resistive, but instruction sheet will show 1000Watts incandescent and 1/4 HP horsepower.
Timer is plugged into extension cord.
Cheaply built product, not meant for constant use.
Timer outlet and distiller plug did not meet firmly, so connection heated up.
Turn off distiller before plugging into outlet so no spark is at the connection point.

I recommend appliance timer for operating appliances.
For example Intermatic HB 113 timer.
http://www.smarthome.com/25071/Intermatic-HB113C-120V-20A-Heavy-Duty-Mechanical-Appliance-Timer/p.aspx
Also heavy duty portable timer like Intermatic P1121
http://waterheatertimer.org/Intermatic-timers-and-manuals.html#appliance

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Using a small flat screwdriver or coin, pry the battery holder open. For battery replacement use two SR44 or LR44When the batteries are in place, press the battery holder back into its original position.

You can view the PDF manual by clicking on the below link.

http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/dt17c%20-%20english.ashx

http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/hb88rc%20-%20english.ashx

First some of these were recalled, see link.

https://www.intermaticstore.com/dt17recall.pgm

The instructions for a 17C should be the same.

http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/dt17c%20-%20english.ashx

intermatic makes a timer for window air conditioners its the same design and only a few bucks more is more robust . I just tested my 175 mh lamp and it draws 1.9 amps on start up the amps go down after it starts.. harbor freight has a cool timer also (cheap) But please try to buy the timer made in the good old USA ....Jay

http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/dt17c%20-%20english.ashx

Here is a link to the manual from www.intermatic.com

Intermatic dt17 timer instructions:
http://waterheatertimer.org/pdf/dt17c-timer-manual.pdf

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I have found the instructions for your model

http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/hb88rc%20-%20english.ashx

I hope that is this will help resolve your issue

I Just downloaded the pdf for the same model. The link to Intermatic is http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/dt500ch.ashx

If that doesn't work then google Intermatic DT500CH pdf and select the return from Intermatic. It's a good timer but not intuitive. I had to look up the manual just to change from daylight savings time.

Here is a link to the instructions for easy setting your unit:

HB88RC Timer

Hope this helps!