[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[TCML] Control Cabinet, X-ray cable, RF-Mains grounding



Hi List,

 

I am in the process of assembling a 28" high 19" rack control cabinet. The
PSU is a very nice GE PT 240/14400V 5KVA of the round epoxy type all
isolated controlled by a saturable reactor capable of current > 30 amps
which both sit on the floor of the rack and a 1256D variac for voltage
control which takes an 8u panel in the front 1.75" * 8 =14". The top panel
will have the metering, key sw, sat adjustment, pilot and HV indicators. I
am using a NEMA #3 AB contactor mounted on the inside wall and a 60 amp
fused disconnect mounted along side the 1256D variac knob on the outside of
the 8u panel.

 

X-ray cable revisited yet again. I have 60 feet of quality and terminated
X-ray cable. I would like to mount standard federal twist jacks on the
cabinet ground to make the cable which would be cut in half easily
removable. A 17KV line surge suppressor would be suspended from the filament
connections across the jack connectors and connected across the PT with 12"
of .5" silicon 50KV wire. The lower and upper deck will be separated by .25"
Lexan self.

 

I know that the spark gap ends need to be stripped back to the PE for 12 to
18". I am on the fence how to best and safely make this connection. Dr.
Resonance suggests grounding one side of the PT and using his RL filter and
thusly one HV feed. The perceived downside of this is that RF and mains
grounds are tied together albeit through the air core and resistor bank. If
I ground anything beyond the jacket and mains ground, I would consider
connecting the inner turn of the primary and the base of the secondary to RF
ground only. I am concerned about RF kick backs that are not absorbed by the
17KV Joslyn Gap at the PT. I don't think streamers will hit the cables but
as an added precaution, I could run that area through some Schedule 40 PVC.
The cabinet will have a very solid mains ground. I will surely put a horn
gap on the Maxwell .1uf / 50KV cap at the coil base. 

 

The spark gap will be an 11" ASRG in series with a fully adjustable Tungsten
series gap to ease the rotary energy dissipation. Has everyone abandoned the
2" ferrite toroid 15-20 turn RF filters? This will be a 12" coil with a
~60x12" toroid. 

 

I really am struggling deciding how to run power to the coil for the safest
operator controls (namely me) and the rack case ground. I used to keep my
pig nearer the coil; but I am wanting a self contained solution here.

 

Thanks,

Jim Mora

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla