Using Step-Down Transformers

[Jason Hancock]

Hi, I'm a Yank living in Russia. Of course, what little gear I have and the gear I plan to purchase is all 110v but the current here is 220v. I have a lot of step-down transformers that can handle either 500 watts or 1000 watts total load each. I'm new to a lot of this and before I fry any gear, I need to know:

1. If I run a UPS or power conditioner (e.g., Furman PL Plus) after the transformer, how much will that subtract from the load that the transformer can handle?

Every other bit o' gear that I'd run would come after the power conditioner or UPS. So, that leads to the next question:

2. I'm considering active or passive near-field monitors (e.g., Yorkville YSM-1). How do I calculate the load they'll put on the transformer? And how does that change if the monitors are active or passive? If I'm running a power amp, how does that figure in?

Yuck....kind of an un-fun question and I may not have even formed it correctly.

I'll be here for at least another year and I'm planning on some major purchases meanwhile. I'll greatly appreciate any help.

Thanks,

Jason

[vox]

Most gear will have it's power consumption printed somewhere on the back, usually near to where the power cord connects. When checking amplifiers or powered speakers the power consumption is NOT the same as the power output, 100watt amp might use 200watts of power, the output and the consumption should both be listed on the back and in the manuals.

If I were you I would also leave a healthy margin, don't run the transformers at full capacity.

[c7sus]

First, the tranformer steps VOLTAGE up or down, which in turn alters the amount of current necessary to do the same amount of "work", in electrical terms. I.e. Horsepower. 1HP equals 745 Watts. A 1000 watt transformer stepping down 220v to 120v will allow you to operate 6.666666AMPS worth of current. This is due to the fact that electrical devices are rated at certain levels but are advised to be operated at 80 percent of their rated capacities if they are used "continuously" or for more than 3 hours at any one time. At least that's how it is in the US according to the National Electrical Code.

Be sure to properly ground the primary and secondary of your tranformers. In fact, what I would do is set up your secondaries to a GFI outlet.

Or, just get a Furman AR PRO for 1500 bucks from FullCompass. It provides 30 amps of 120v from single-phase 220-240v services.

If you have any questions, feel free to ask away........

Oh yeah...... P= IxE

Where P is the power in Watts, I is current in Amps, and E is the voltage.......