The problem is likely the 3-wayness of your dimmer switch. It sounds like you are connecting power and the iron to the runners travelers, instead of through the output pole terminal.
___[traveler]____
hot _____./ \.____ switched wire
___[traveler]____ |
|
O [light socket (on)]
|
neutral
___[traveler]____
hot _____. \.____ switched wire
\___[traveler]____ |
|
O [light socket (off)]
|
neutral
Make sure you don't have your's set up like this:
___ pwr
wirecap _____./
___ iron
Also make sure you have clicked over the dimmer to the correct traveler or wire the two travelers together (the switch will always be on then).
of the
There are some electronic dimmers that detect the other switch's position and go to full brightness, which would probably not work correctly if only partly wired.
You could look at a simpler dimmer switch or cord like this http://goo.gl/Mnwbe, though as other's mentioned in the comments, it's probably only $20-30 more to get a new variable wattage iron.
Whatever you do, please be careful.
A 0.5W 240V light will have a circuit resistance of about 115kohms. Given the circuit you have described, what you measure doesn't suprise me. What's the resistance of the black box? Is it about 65kohm?
It's impossible to say if you are using the wrong sort of light - what were expectations for the as-yet-undisclosed black box. Wiring in parallel may be an option but I can't tell what you wanted from what you've told us.
Best Answer
I would say "eyup!" This, however requires dealings with high voltage, high power electronics, so the first thing to look for is safety precautions. I have a boilerplate:
'Round where I live in Alberta, Canada, the Earth wire is green, and should be wired directly to the cast iron lamp. The hot (not green, gray, or white; often black or red) and neutral (gray or white) are connected to the two screws. They should only be stripped/exposed enough to wrap around the screw once, and not over itself. Ensure the Earth wire is connected to the Earth prong on the socket plug with a multimeter continuity test. Try it out! If a breaker trips, pat yourself on the back for connecting the Earth wire, as it may have just saved your life -- there is a short to the lamp, and power should be shut off and all connections checked with a multimeter.
The Earth wire connection is not required for operation -- just safety.