On November 23, 2017 7:46 AM, Stu jaxon wrote:
On Wednesday, November 22, 2017 at 3:41:45 PM UTC-5, Trevor Wilson wrote:
On 23/11/2017 7:16 AM, Stu jaxon wrote:
On Wednesday, November 22, 2017 at 2:39:09 PM UTC-5, J.B. Wood wrote:
On 11/22/2017 01:50 PM, Stu jaxon wrote:
hi group, does anyone know if i can use this= 750 Watt Voltage Converter Transformer Heavy Duty Step Up/Down 750W 110-220V as an isolation transformer, it does have output of 110v, ? thanks,


Hello, and do you have a particular make and model number of device in
mind? An marketed as an AC isolation transformers usually doesn't
provide voltage conversion with input (primary) to output (secondary)
energy transfer solely via magnetic coupling. There are also adjustable
autotransformers (e.g. the venerable Variac brand) that, for example,
takes 120 VAC at input and can provides 0-130 VAC output. The primary
and secondaries of these devices aren't conductively isolated (as an
ohmmeter test will confirm). There are also devices which combine both
isolation and adjustable autotransformer function in one enclosure. Or
you can simply take, say, a 120 VAC-to-120 VAC isolation transformer and
follow it with an adjustable autotransformer, keeping in mind the
maximum AC current/power ratings of the devices. Sincerely,

--
J. B. Wood e-mail:

here's the model Norstar ST-750.. it's on ebay for half price used. so more or less this just a surge protector.?

**No. It's a step-down transformer, or autoformer. No way of knowing,
unless you can contact the manufacturer, or measure it yourself. I doubt
that it is an isolation transformer.

Which begs the question: Why do you need an isolation transformer?

to protect my equipment, i picked up a new hobby.

From what? And when you say 'surge protector', could you also have 'surge arrestor' (for much un-predictably higher un-controlled voltage input) in mind, as well?

To start with, your hobby device power processing should connect to an un-insulated copper or aluminum wire that should be in properly grounded and secured contact with your facility's (cold) water main.
Additionally, use specifically GFCI-advertized outlets when you think there is danger to people or property. It says that in the recent NEC- book rules, doesn't it?