Function generator outputs are connected to earth?

[Flyback]

Hi,
Do you agree, that this function generator's input and outputs are all referenced to earth ground, and it cannot be disconnected from earth? ground?

TG550 func gen

https://resources.aimtti.com/datasheets/AIM-TG550_function_generator_data_sheet-Iss2A.pdf

 

[danadak]

It would be pretty unusual to have a full floating f() generator, or so I think. I dont
see a differential marked pair of BNC out.

Measure ohms between bnc shell and line neutral of its line cord.

You could use an AC line isolation transformer to achieve some semblance of floating, but
datasheet/manual may not spec common mode limits which you could violate depending
on how it was designed and fry it and/or whatever its connected to.

 

[Nigel Goodwin]

Not a very useful datasheet, it doesn't even give a picture of the back of the unit

Does it have a three core mains lead or a two core one?, as it's in a plastic case it's likely to be a class-II device with a two core mains lead, so no earth. Such devices are often two core, if it's three core them measure from the earth pin to the BNC sockets see if it reads between them, if it's earthed it will be low resistance.

I wouldn't measure from neutral to BNC, as it shouldn't be connected to neutral.

 

[AnalogKid]

Measure ohms between BNC shell and *ground* of its line cord.

ak

 

[Externet]

My audio generator has balanced or unbalanced selection...

And a serious instrument should too.

 

[danadak]

My audio generator has balanced or unbalanced selection...

View attachment 147648
And a serious instrument should too.

Fascinating, what kind of common mode will it tolerate ?

 

[ChrisP58]

Hi,
Do you agree, that this function generator's input and outputs are all referenced to earth ground, and it cannot be disconnected from earth? ground?

TG550 func gen

https://resources.aimtti.com/datasheets/AIM-TG550_function_generator_data_sheet-Iss2A.pdf

Since the BNC connector all have a ground symbol by them, it seems pretty clear to me that they would be grounded.

 

[Nigel Goodwin]

Since the BNC connector all have a ground symbol by them, it seems pretty clear to me that they would be grounded.
View attachment 147650

Except it's a chassis symbol, not a ground symbol.

 

[Externet]

Fascinating, what kind of common mode will it tolerate ?

Hi. Do not know how to answer that. Did not find it in its manual,

 

[Externet]

Except it's a chassis symbol, not a ground symbol.

If the chassis is connected to the power cord 'ground' green conductor; is the BNC symbol both ground, common and chassis ?... And mains neutral too at the breaker box ?

How is the european ground at the breaker box ? Attached to neutral also ?

 

[Nigel Goodwin]

If the chassis is connected to the power cord 'ground' green conductor; is the BNC symbol both ground, common and chassis ?... And mains neutral too at the breaker box ?

How is the european ground at the breaker box ? Attached to neutral also ?

You're assuming it has a three core mains lead?, it's more likely a class-2 device, double insulated with no earth lead. As the front symbol is chassis, it's another potential indication that it's only a two core lead?.

But the datasheet in the OP is completely useless, and tells you almost nothing. However, the instruction book isn't much better (no pictures or diagrams), but it does say "WARNING! THIS INSTRUMENT MUST BE EARTHED", and a lot of searching finds a reference to it being class-I.

I can't comment on Europe, but in the UK earth is either a local mains spike, or connected to neutral, and earthed at the sub-station transformer.

 

[AnalogKid]

On the right side, below the centerline is a switch labeled GND / FLOAT. It looks like this gives you the option of connecting the internal signal ground to the chassis / earth ground.

ak

 

[Tony Stewart]

Hi,
Do you agree, that this function generator's input and outputs are all referenced to earth ground, and it cannot be disconnected from earth? ground?

TG550 func gen

https://resources.aimtti.com/datasheets/AIM-TG550_function_generator_data_sheet-Iss2A.pdf

It seemed obvious to me , so I had to find proof. p.7 https://resources.aimtti.com/manuals/TG550_Instruction_Manual-Iss9.pdf

"Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous. Intentional interruption is prohibited. The protective action must not be negated by the use of an extension cord without a protective conductor"

Yes, you can disconnect at your own peril during a thunderstorm or measure the stray leakage in the transformer with your hand on PE. Possibly, they intended you to want an external PE to avoid a ground loop on the DUT. Hence the CYA legalese.

 

[Nigel Goodwin]

On the right side, below the centerline is a switch labeled GND / FLOAT. It looks like this gives you the option of connecting the internal signal ground to the chassis / earth ground.

ak

You're looking at the wrong generator

It's the white one in the PDF in the OP.