Hitachi V-650F

[rmcloud]

Hi!

I purchased a Hitachi V-650F oscilloscope on ebay. It functions, however I took
a look inside and noticed that the earth ground connection has been disconnected. my
first thought is that I should reconnect it for safety reasons. I am learning as much as I
can about earth ground and why scopes are connected in this way. I would just like to ask for advice
and perhaps understand why it would have been disconnected
to begin with.

Thanks in advance!
Bob

[PKTKS]

This question is a matter of debate.

The 3rd pin or earth is not required.
It is assumed to be a "safe" fallback in case of discharge.

In some grid areas there is not even a 3rd pin available
In those cases even "connected" it connects nothing.

The real "safe" thing in a bench is having isolation transformers.
The advent of Switch Mode PS have done this a wild problem

**IF** your (OLD) scope functions based on an isolated transformer
just forget that 3rd pin

Otherwise IMHO the best safe option is still an isolation transformer
One for the instrumentation
Other for the loads

More safe than having an earth connection wide spread on your bench
But that is a matter for debate

Paul

[tautech]

It's safer to leave the scope grounded and have the DUT in isolation from mains ground.

Consider where you might clip the reference (gnd) lead from a scope probe.
If the scope is removed from mains ground the scope chassis takes on the same potential as the probe reference lead so that can place a significant risk to the user of electric shock or even death.
This is known as 'floating the scope' and a practice generally frowned upon.
The safest workaround is to get an use differential probes.