I think OP need to go brush up on his Ohms law before going any further.
Look at it like this - in Europe we have 230 Volts in our wall outlets. The outlets are fused by a 10 Amp fuse. 10 Amp * 230 is 2.300 Watts.
Just because the wall outlet is capable of delivering 2.300 Watts, you can still plug a 25 Watt lamp into the outlet without anything blowing up. The lamp (the load ) takes what it needs - not what is available.
You can look at constant current a bit like the fuse. The size of the fuse sets how much power you can use, before power if cut off (to protect the appliance and house wiring) - The constant current on a power supply can be seen the same way. If your circuit uses 1 Amp in normal operation, you can set the Constant current setting to 1.5 Amps - this way, only 50% extra power is available to fry your wiring etc. if something goes horribly wrong and you short anything out.
// Per.