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Re: Designing safety from the beginning.

Hi Alex, all,

My comments are interspread through out your mail.

 1.  Has anyone had any success in using a dead man's type switch as the
 main power switch for the coil.

I always use a relay (relay coil powered by low voltage) in series with my
main lines plus a mains switch. This way I can remote control the coil via a
pushbutton. Releasing (or dropping) the pushbutton kills power to the coil,
immediately. I would never just use a simple on/off switch (sure holding a
pushbutton all the time is a pain, but it is safe) to turn my coils on and
off. If you have kids around the house I would go for a key switch in series
with the pushbutton. 

a.) Use the biggest relay you can find (esp. if you are running pig power).
The best relay in the world won´t help in the case of emergency if the
contacts weld together !! I use an old relay contacts rated at 300A (okay,
slight overkill here). I got it from an old DC argon/tig stabilizer. It was
designed to switch the welding current on and off. 

As a rule of thumb I go for contact material that resists welding and for a
rating of at least three times the max primary current the xformer draws. If
you can find one go for a big two contact relay. This way you can totally
disconnect the hv xformer from the mains (L and (!) N) 

b.) While working on your coil never, ever, rely on the relay to disconnect
you from the mains. PULL THE PLUG, every time. 

 2.  Am I right in my assumption that my main power switch should be in
 the AC line leading to my transformer and not on one of the higher
 voltage lines?

Yes, first of all a HV relay/switch is way too expensive. Second, if your
xformer blows, a switch in the HV line won´t do anything to help you
 
 3.  Has anyone successfully and safely discharged the capacitor(s) using
 a switch on the control panel?
 
KEEP HV out of your control panel !! (and that way away from you). 

The only way you could do this would be via a HV relay and resistor. There is
a problem, however: If you get a kickback from the tc tank, you could get an
arc across this relay (unless it is a big and expensive unit). 
Plus you would put your life in the hands of a relay (what if it fails to
discharge the caps?). Never take anything for granted running HV equipment.
Discharge caps via a long grounded rod with an insulated handle.

 4.  Would it be possible to design the main power switch so that in one
 position it would turn the power on and in the other it would drain the
 capicitors?  Would this work better with a three position switch?  (For a
 "null" position in the middle.) Would it be better to do this with two
 differently rated switches?

See above.
 
 5.  With regard to safety, are there any gauges, meter's, etc. which
 should be designed into the control box?

Well, depending on spare cash, safety/info wanted:
a.) Voltmeter
b.) Amperemeter
c.) Variac
d.) "Plugged-in" light (lights up as soon as your plug is in the wall outlet).
Use the biggest "redest" light bulb you can find.
e.) HV "power on" light
f.) Remote control jack and switch,
g.) If your mains are high current fused: A set of seperate "Tesla coil" fuses
h.) Ground your control unit
i.) Ground fault interrupter
j.) Outlet that supplies power all the time (main plug plugged in). Good for
lights, etc
k.) Outlet that supplies power once the coil is energized
l.) A seperate switch/variac/light for your (if used) RSG.

Coiler greets from germany,
Reinhard