Our source of domestic water is a spring. There is a pump enclosed in
a pump house and it operates on 220V. I want to install a filter
system that uses a clock (110V) to control backflushing of the
limestone filter. My problem is, the power to the pumphouse consists
of two hots and a ground, no neutral. What I want to know is, can I
use one of those step down transformers to get 110V to operate the
clock? As near as I can determine from websites describing the
transformers, they are made to be used with 220V european (or
elsewhere in the world) power. Those voltages are a single hot with
respect to ground while US 220V is what it is, with each hot at 220V
with respect to the other hot. Can I use one of these transformers
with US 220V input? I can't see much of any other option rather than
replacing the wiring to the pumphouse which would be beaucoup
expensive (underground wiring) given the distance. Any help is
On Sat, 16 Oct 2004 12:47:03 -0700, Tony Hwang wrote
I emphatically disagree with Mr. Hwang's suggestion. You should never use
the equipment ground as a neutral return path. It will certainly "work", but
you have potential touch voltage on the entire ground path (equipment
housings, conduit, etc.) back to the panel. If that path gets interrupted
anywhere by a break or high-resistance connection, you will have a very
hazardous situation. Using the ground in this way is, of course, a code
violation and with good reason.
I am not familiar with the European to US transformers, perhaps another
poster can tell you if they're suitable.
However, you certainly can get a small hard-wired 220V to 110V step down
transformer for your application, but it's not a Home Depot item. This sort
of "separately derived system" is done all the time in industrial/commercial
installations. You end up with a transformer feeding a small panel with a
breaker for the 110V circuit. One of the transformer secondary terminals is
grounded in the panel and you have a "normal" 110V to neutral branch circuit.
It's not hard to do, but the details (particularly concerning grounding) are
a little hard to understand. Depending on how ambitious you are, it may be
better to have an electrician do this.
Whatever you do, please don't use the ground as a neutral.
Yup, ditto what you said on using the ground.
Plenty of control transformers around cheap enough, suggest an electric
motor shop--these are often salvaged from scrapped wood and metalworking
machinery, or perhaps try Ebay.........
Ground one tap of the 110v ( secondary ) side to your existing ground, and
use that also as your neutral--the other secondary tap becomes your hot leg.
If you connect one side to the ground, it's not floating.
Has _nothing_ to do with the clock, other than it's providing
a continuous current flow thru the ground.
If that ground ever gets interrupted, then _everything_ that's
grounded in the shed (including the pump housing) goes live.
Double plus ungood.
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
There are clocks that work on 220-240 volts. I have used them a lot on
Back feeding the European transformer will limit the amount of current
available. IE 220 in and 120 out. They are not made to work that way. Also
a lot of European 220 is 50 hz which will not work with a clock motor
looking for 60hz.
Call the filter manufacture and ask for an 220 volt model. Or an conversion
for the one you have.
Outgoing mail is certified Virus Free.
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The frequency is not an issue. Apparently he has a clock motor, where
the only problem is it needs 110, rather than the 220V which is
available to run it. Any transformer that works at 50hz will work at
60hz for this application. Whatever frequency he puts in, that is
what will come out.
Nor should current be an issue, since he's only running a clock.
That's exactly the small kind of load these international converters
are intended to run.
firstname.lastname@example.org (Blackdogs) wrote in message
The short answer is yes, the transformer has two wires coming in with
220 and 2 going out with 110, so physically it will work. As to
whether you can hook it up to be safe and pass code, that is another
question that I don't know the answer to, ie what kind of outlet,
plug, is it allowed to hook the particular clock device in via a plug,
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