On 10/16/2015 06:34 PM, dpb wrote:
On 10/16/2015 5:53 PM, philo wrote:
On 10/16/2015 05:48 PM, dpb wrote:
On 10/16/2015 5:21 PM, philo wrote:
...

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.

Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is
long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I don't know your scope of "high power circuitry" but I'm guessing it's
far more than a house feed. I've had very good success over the years
in doing so as long as the connector/wire haven't been severely damaged.

The key is first gotta look at what the situation really is, though, not
just assume tightening alone will be enough.



I worked with circuits 80 amps and above...which would come into the
range of a house power feed.

I do believe your statement however and assume it was just a very small
arc on a relatively low current circuit.

What voltage(s)? I've worked on/used HV instrumentation where it's
definitely true that any imperfection is the death of the connectors,
and on high amperage busses (kAmp power-plant kinda' things) where it's
also true, but really never had any difficulties with the 100A 240V or
less unless it was truly awful.



Since I worked on batteries and chargers the voltage was usually under
72 volts... but it was DC which is a whole different thing from AC.

My main point however was that if the OP heard hissing there was
undoubtedly arcing and he really needs to call an electrician.



(the rest read but snipped for brevity)