Isolation Transformer

[tech2014]

Will any of these work for testing primary side of SMPS with scope?

http://www.ebay.com/sch/i.html?_from...ormer&_sacat=0

[jotto]

Re: Isolation Transformer

That will work, but if you want to invest a bit more I would get the Sencore PR570. It does a lot more then just a isolation transformer.

The main reason I like this unit is because you can set the trip current, check leakage.

[tech2014]

Re: Isolation Transformer

being able to set the trip current would be a great asset, thanks

[mockingbird]

Re: Isolation Transformer

Someone correct this if it's inaccurate please, but you need a "technician's" isolation transformer or else the ground is connected to neutral.

[budm]

Re: Isolation Transformer

Someone correct this if it's inaccurate please, but you need a "technician's" isolation transformer or else the ground is connected to neutral.

That is correct, the ISOLATION Transformer output should NOT have Neutral tied to the safety GND.
It must be verified that the LINE or NEUTRAL on the outlet of the ISOLATION transformer has no electrical connection to safety GND or to the primary side.
Some of the TRIPPLITE ISOLATION transformer have neutral connected to safety GND.

[tech2014]

Re: Isolation Transformer

Hey guys. Below is a link to the isolation transformer that I got on eBay.

http://www.alliedelec.com/stancor-gis-1000/70213217/

[budm]

Re: Isolation Transformer

Spec sheet: STANCOR GSxx

[tech2014]

Re: Isolation Transformer

Thanks budm. Do I need to make any modifications?

[budm]

Re: Isolation Transformer

No.

[tech2014]

Re: Isolation Transformer

awesome, thanks. So do I just connect the power cord from my scope and/or device under test into the output side of the isolation transformer?

[budm]

Re: Isolation Transformer

Scope to the regular outlet, what ever you are fixing into the isolation transformer.

[tech2014]

Re: Isolation Transformer

ok thanks.

[tech2014]

Re: Isolation Transformer

ok I got my isolation transformer. I connected the transformer mains power into the wall outlet, and connected my SMPS I am testing, to the output cable of the isolation transformer. For some reason I am only getting about 45Volts AC out of the isolation transformer. Is there something wrong with it? I got it on eBay.

[R_J]

Re: Isolation Transformer

Are there any other numbers on it? sounds like its a stepdown transformer from 220 - 100 volts, and inputing 110 into the primary would give about 55 volts out
it could be an auto transformer and not an isolation transfomer, with it unpluged can you measure resistance from the primary to the secondary?
Maybe its a GISD-1000

[dick_barton]

Re: Isolation Transformer

It's a step-up auto-transformer which has both the inputs and output on the same winding.
115V ac in for 230V ac out and the earth is connected straight though.

It is not an isolation transformer so is not suitable or safe for what you want to do.

[stj]

Re: Isolation Transformer

just an idea, but if you only need to use the scope for a few min's - why not use a UPS and pull the input before you do the testing?

[budm]

Re: Isolation Transformer

Are you sure you received the GIS-1000 as shown in the web site and matched the PDF spec I provided? 1000VA is a BIG transformer.
Show us the EBAY seller web page and the picture of the unit you bought.
I see some on EBAY:
http://www.ebay.com/itm/Stancor-GIS-...oAAOSwd2xXP~t-

[dick_barton]

Re: Isolation Transformer

Hey guys. Below is a link to the isolation transformer that I got on eBay.

http://www.alliedelec.com/stancor-gis-1000/70213217/

Hi Bud,
The transformer I was referring to was from the one in the above link.

[budm]

Re: Isolation Transformer

Hi Bud,
The transformer I was referring to was from the one in the above link.

If you look at the spec sheet I provided, the GIS-1000 is the Isolation transformer.
The description saying it is Autotransformer is wrong on that web page.

[tech2014]

Re: Isolation Transformer

Are you sure you received the GIS-1000 as shown in the web site and matched the PDF spec I provided? 1000VA is a BIG transformer.
Show us the EBAY seller web page and the picture of the unit you bought.
I see some on EBAY:
http://www.ebay.com/itm/Stancor-GIS-...oAAOSwd2xXP~t-

Yes. It is big and very heavy. The listing link is below.

http://www.ebay.ca/itm/222226718872