Lab power supply

[Kari Laine]

Hi,

I got two lab power supplies, which have amp and voltage control.

Now I need to know whether the ground on them is floating or not.
I mean that there is no direct connection from the minus pole to
electricity network. I don't know the right word for it in English.
But what I am after is that do they disconnect the device connected to
them from the electrical network with a transformer.

Hope someone knows how to measure that somehow. They are installed in
tight place and I would not rather to dig them out. Air circulation is
adequate - I think...

Best Regards
Kari

--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com (I am just a satisfied customer)

 

[Bob Eld]

"Kari Laine" <klaine8@gmail.com> wrote in message
news:AL6dnWXSXKtHTfvWnZ2dnUVZ7qydnZ2d@giganews.com...

Hi,

I got two lab power supplies, which have amp and voltage control.

Now I need to know whether the ground on them is floating or not.
I mean that there is no direct connection from the minus pole to
electricity network. I don't know the right word for it in English.
But what I am after is that do they disconnect the device connected to
them from the electrical network with a transformer.

Hope someone knows how to measure that somehow. They are installed in
tight place and I would not rather to dig them out. Air circulation is
adequate - I think...

Best Regards
Kari

--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com (I am just a satisfied customer)

With the supplies turned off, measure the resistance of both the minus pole
and the positive pole of the power supplies to the power or chassis ground.
The supplies should be disconnected from the loads to insure that any
measured resistance is not external to the supplies. If the resistance is in
the megohm range or higher, the supplies are isolated. If the supplies are
not isolated, the resistance would measure a few ohms or less to ground. Any
other resistance means that there is some sort of leakage or resistance path
to ground. Repeat the measurements with the ohmmeter leads reversed to
insure that the isolation is bipolar and not through a diode.