Isolation Transformers

Hi Kalali,

I'm not sure what you have. Can you post the make and model?

An isolation transformer by itself does not regulate voltage. It does eliminate DC and prevent certain types of shock, as well reduce noise due to the inductance. 

A voltage regulator may also be present, but these can be with or without the isolation component. The benefit here is, of course, a tightly regulated AC voltage, though not necessarily surge protection, and it may take a little for the regulator to adjust to incoming and outgoing conditions. 

Best,


E

Isolation transformers have many uses. Google is your friend, punch in what model you ended up with and it's specs. Start with the link below for an explanation to the basics:
http://www.shure.com/americas/support/find-an-answer/transformers-when-to-use-and-how-does-it-work

It was apparently used in a hospital.

What is the Kva rating? It will say on the data plate.

Does it say ’Medical Grade’ anywhere on it?

If yes:
Most medical grade isolation transformer I have ran across float the secondary winding above ground. That means both AC Line contacts on the receptacle outlets are fed from Hot ungrounded legs, conductors. Neither of the two hot conductors have a reference to ground. Therein, not to the metal case/enclosure of the transformer or to the ground contact of the receptacle outlets.

I would suggest you use a volt meter and measure for voltage from both contacts to the equipment ground contact on the outlets.


If the isolation transformer is wired as a Grounded Power System:
Short slot of the outlet to equipment ground should measure 120VAC nominal. (You said it runs 124Vac.)Longer slot of the two, or ’T’ slot, the neutral contact should measure a solid zero volts to ground.

If the isolation transformer was left ungrounded then you have an Isolated Power System. Any voltage readings from either contact to ground will be phantom voltage. Usually a digital meter reading will be all over the place and will not hold steady.

Medical grade transformers are meant to be used by qualified personnel only.
If your transformer floats the secondary above ground you should have an electrician wire it as a grounded power system. It’s simple do.

.

When did they start printing ’hospital grade’ on anything that was? dang, has it really changed that much since I was in the field? OP did say older isolation transformer?

I guess things have: Hospital grade receptacles include the same markings that appear on general use receptacles, and also include “Hospital Grade” or “Hosp. Grade”, typically on the back of the receptacle where visible during installation

Wasn’t always so. I guess code revisions took a big friggin change to assure no mistake. Guess they factored in no one pays attention to the spec sheets any longer. ..hmph
Reminds me of those on the job concentrating solely on their electrical prints and were clueless to look at the architectural and others...*laffs

In Australia 230v to 230v isolation transformers I have use them on my source gear since the 80’s. they provide "Galvanic Isolation" from the mains and block/filter any dc on the mains.

For the US
http://www.surplussales.com/item/_tp/91092-12.html
https://www.bkprecision.com/products/power-supplies/1604A-single-output-isolation-transformer.html

Cheers George