4 can lights wired to two 3 wire Lutron

Is original a 3-way dimmer (2 or more switches control same light fixture)?

You probably had a fan/light fixture there. One set of wires (probably coming from the dimmer) would be for the light. The other set of wires (probably coming from the switch) would be for the fan. With the power off, temporarily hook up two lamps, one to each set of wires. Then turn on the power and see which switch controls which wires. It is possible that one set of wires is passing through to another light fixture - in that case, that wire will be dead. Good luck!

If your dimmer was working correctly in the past, and suddenly started doing this, then your dimmer is probably gone bad.

If this is a new installation, the wiring could be wrong, or the dimmer could be wrong.
For example you purchased the companion or accessory dimmer rather than the main dimmer.
Or the wiring is put on the wrong screw.

If this is a new installation, add a comment and fill in the information and I can troubleshoot.

What is the model number of your dimmer.
For example the Maestro MIR600.
Are you replacing a single-pole switch or a 3-way switch?
Are you using 2 dimmers in a 3-way application?
What color are the screws on your dimmer?
What color are your wires and which screw do they go to?

You posted under Lutron 3-way dimmer.

You didn't say the number of screw terminals on device or color of those screws.
If your device has two brass screws, then it is single pole.
If your device has 2 brass screws and 1 dark screw, then device is 3-way
If you are replacing 3-way switch, identify wire on dark screw >> connect this wire to dark screw on dimmer. Other two wires connect to either brass screw.

If device has wires instead of screws, the color of those wires is an important clue.
Answer back with the colors of those wire and it is easier to help.

Different dimmers are suitable for different types of lighting.
In an effort to help you, I searched my files for Lutron dimmers.
Lutron has 17 dimmer types, with numerous models under each type
They don't show DL-3PS
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/Pages/DimmersSwitches.aspx

Lutron has NT-3PS
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/NovaTDimmer/Pages/ModelNumbers.aspx

The NT-3PS is a 3-way dimmer.
Here is wiring manual:
http://www.lutron.com/TechnicalDocumentLibrary/wallbox_wiring_6_7.pdf

If the help above does not get you going, answer back with more information and we can help.

I have spent considerable time on the Lutron site past couple days looking at their dimmers.

Lutron has a lot of dimmer varieties. The basic breakdown is 600Watt and 1000Watt. But different dimmers control different types of lighting.
Here is the long list of Lutron dimmer manuals:
Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

http://www.lutron.com/Service-Support/Technical/InstallationInstructions/Pages/InstallationInstructions.aspx?syst=Dimmers+%26+Switches&prodn=Maestro%C2%AE+dimmer+%26+switch


I cannot find a specific troubleshoot manual for Lutron dimmers
So I suggest 4 things:
1) Feel the dimmer switch for heat >>> if it is getting hot (not warm), then that dimmer is dangerous, so remove dimmer immediately, add up your total bulb wattage to make sure you're below the 600 or 1000 watt capacity of you model dimmer
2) Look at the list of manuals shown at link, and make sure your dimmer matches the type of bulb you are using. Your dimmer model number and wattage should be printed on side or back of dimmer.
3) These dimmers use electronics to control the lights. Electronics go bad. The higher the wattage controlled by your dimmer, the more heat, and the shorter the dimmer life.
4) Short in the wires. Replace your dimmer with one from Home Depot and see if the condition persists. If it does, then a short is probably somewhere in that circuit. Troubleshooting a short is another long answer that needs more wiring detail ... please repost if you have a short.

First off, if your dimmer is getting hot, then there is something wrong. This is dangerous. Do not leave that dimmer in the wall. Remove it.

1) A typical wall switch controls up to 1400 Watts. Look at the watt rating of your dimmer. A 600 watt dimmer will control up to 600 watts. If you have 600 watts on your dimmer, expect a shortened lifespan for that device. If you have more than 600 Watts, expect overheating and possible fire.

2) Lutron makes 1000 Watt dimmers
http://www.lutron.com/Service-Support/Technical/InstallationInstructions/Pages/InstallationInstructions.aspx?syst=Dimmers+%26+Switches&prodn=Maestro%C2%AE+dimmer+%26+switch

3) Type of bulb: Review the specs shown on link above because they show wattage, and they also show which light the dimmer is made to control

4) If your lights are on a 3-way switch, then dimmer has 3 screws and connects to 3 wires. If your wiring is incorrect, it might give symptoms shown above.
If your switch had 2 wires and you put those wires on a dimmer with 3 screws, it might be wired incorrectly.
Check wiring. Re-post a question if your are confused about details.

5) There might be a short in the circuit ... or in the dimmer ... replace dimmer with another one from Home Depot and see if symptoms persist. Disconnect ground wire as a test only and see if symptoms disappear ... if so then there is a short somewhere in the circuit
Don't burn the house down.

Lutron Dimmer manuals
http://www.lutron.com/Service-Support/Technical/InstallationInstructions/Pages/InstallationInstructions.aspx?syst=Dimmers+%26+Switches&prodn=Maestro%C2%AE+dimmer+%26+switch

Lutron manuals show a couple things that might be affecting you lights.
1) Wattage: If you have wrong wattage dimmer
2) Type of light bulb: Dimmers work on different types of bulbs
3) Wiring: You say you got 3 wires going to the chandelier? Why you got 3 wires? Is this a 3 way switch? Are the chandelier bulbs wired separately so you can control groups of bulbs with different switches?
Does the dimmer have 3 screws? A dark-colored screw and 2 brass screws? If so, then that sounds like a 3-way dimmer. A 3-way, is where more than one switch controls the same light.

Does the dimmer have 2 screws? Then that dimmer controls a single circuit. Your black Hot wire from breaker box connects to one screw and the black wire to Load connects to other screw.
A quick glance at Lutron wiring manual shows that Hot and Load wires connect to either screw.
The question is your 3-wires from the chandelier ... does the black Hot wire from breaker arrive in the ceiling box first? Or does it arrive in the wall box first? If your Hot arrives in ceiling box, then the Hot must come down to the switch box and connect to a screw on the dimmer >>> a second wire connects to other screw on dimmer and travels up to the ceiling box where it connects to black wire on chandelier. The white wire on chandelier connects to white Neutral.
4) Dimmer might be bad

1) Overview of product indicates it dims by electronics (they say saves 15% electricity)
The electronics might be bad
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/MaestroDimmerSwitch/Pages/Overview.aspx

2) Load types
Different dimmers are made to work with different types of lighting
Depending on your model number, the type of load may be a factor
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/MaestroDimmerSwitch/Pages/Models.aspx

3) Total load
A regular 15 amp light switch carries 1440 watts
If you have the 600 Watt dimmer, load wattage should not exceed 600W >>> add up total bulb wattage

4) Lutron seems to have about 60 different manuals
A quick look at the wiring seems straightforward 1-1 wiring replacement with ordinary switch
Did you connect ground wire to green screw on dimmer?

5) If the dimmer and load requirements match with the dimmer you own, I think the problem might be a short .... exactly where the short is located is solvable by testing the lights and timer and surrounding circuits with a multi-tester >>> the testing would start at the dimmer.

6) All considered, you could replace the dimmer with another one from Home Depot and see if same problem persists.

As a general rule, grounding will not affect operation of dimmer.
Type of dimmer, type of switch being replaced, type of load, and how you connect wires will affect dimmer.

Here is Lutron dimmer switch page
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/Pages/DimmersSwitches.aspx

What is the load? Are you wiring dimmer to a ballast? Or fan? Or incandescent lights? Or florescent lights?
Are you replacing a 2-way or 3-way switch?
What color are your dimmer wires?
How many wires were connected to switch?
Can you re-install the switch, and know where each wire went?
Did you replace a light with a fan, and then want the dimmer to slow the fan? Not every dimmer will work with a fan, or florescent lights.
Dimmers cannot dim LED lights.

If I know what type switch you are replacing, and the type of load you want to control, and the specific dimmer you have, I can answer the question.

In general practice, you can only install ONE 3-way dimmer switch to control the lights. If you use two regular 3-way dimmer switches, the circuit won't work.

However, newer technology allows for double 3-way dimming from different locations. See this article about how to do this:

http://www.smarthome.com/2494M3/SwitchLinc-3-Way-Dimmer-INSTEON-3-Way-Dimmer-Kit/p.aspx