11 Dec
2002
11 Dec
'02
1:29 p.m.
From: ard(a)p850ug1.demon.co.uk
> Jesus H Kraist!!!!! Zane, you need to stick with shit you know
about,
and leave the
electrical advice to folks who understand the difference
between voltage and current.
DO NOT plug your 120v PDP11 into a 220V Dryer Outlet!!!!!
DO NOT plug your 120v PDP11 into a 220V Dryer Outlet!!!!!
I will agree with that, _but_
(1), IIRC the 11/44 has a handy switch on/in the PSU to select between
115V and 230V input. It would be easy to flip that.
(2) I was under the impression that US dryers, while using 230V for the
heating elements, used 115V for the timer. And that US domestic mains was
a centre-tapped (The tap being called 'neutral') 230V supply.
In which case, if there's a neutral feed to the dryer socket which can
carry the same current (20A) as the 2 live feeds (one from each side of
the mains), then you could run the 11/44 between one live feed and
neutral. This probably breaks code in a dozen places, but....
11 Dec
11 Dec
2:12 p.m.
New subject: dryers was Re: Acquired a PDP11/44, but missing M7095
----- Original Message -----
From: "Dwight K. Elvey" <dwightk.elvey(a)amd.com>
To: <cctalk(a)classiccmp.org>
Sent: Wednesday, December 11, 2002 7:31 PM
Subject: Re: Acquired a PDP11/44, but missing M7095
Hi
My drier has a three pin plug, Two hots and one ground,
No Neutral!
I would assume that if anyhting ran on 115, it would be
through a transformer but I think the time is 230V as
well.
The old style dryer plug was a 30A 240V plug with two hots and a ground.
These are only legal now for replacment of existing installations, and I
expect that to go away shortly too. The new style is the
much-more-safe-yet-oh-so-much-more-expensive-for-some-unknown-reason 5-prong
grounded outlet.
The old style dryers that I've looked at used 120V timers connected between
one hot leg and the chassis ground. It might not live up to the latest and
greatest code, but I was never shocked by one. YMMV.
Dwight
Bob
12 Dec
12 Dec
2:02 p.m.
New subject: dryers was Re: Acquired a PDP11/44, but missing M7095
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13 Dec
13 Dec
12:32 a.m.
New subject: dryers was Re: Acquired a PDP11/44, but missing M7095
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <cctalk(a)classiccmp.org>
Sent: Thursday, December 12, 2002 7:41 PM
Subject: Re: dryers was Re: Acquired a PDP11/44, but missing M7095
I understand the problems it can cause. My problems with these sort of
regulatory agencies are their complete arrogance and flighty nature. Every
three years, they come out with a new Code. Which is fine, but they
absolutely *insist* that the current Code is the most safe, and that all
others are unsafe. The problem I see with that statement is that they said
the exact same thing three years earlier, and look what became of that... I
just can't see a committee publishing the best of anything, let alone
something as complex as this.
Note: I do think the Code gets better and better. I follow it with all my
work. Please read, understand, and follow the Code when working with
electricity!
>
> The old style dryers that I've looked at used 120V timers connected
between
> one hot leg and the chassis ground. It might not
live up to the latest
and
greatest code,
but I was never shocked by one. YMMV.
I think the main hazard is if the earth/neutral wire becomes
open-circuit, then the frame of the drier becomes live via the timer
motor windings, which are not that high impedance. I don't like large,
live, metal objects around, particularly if there's also water about (and
this would be likely near a clothes drier).
That's why there are separate neutral and earth wires, even if they are
then connected together at one point in the installation. If the neutral
wire breaks, the device fails to work, but it doesn't become live. If the
earth wire breaks, the device carries on working, but will become live
_if another fault develops_. Combine the 2 into one wire, and if that
breaks, the device stops work _and_ becomes live.
-tony
Bob
7893
days inactive
7895
days old
3 comments
3 participants
participants (3)
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ard＠p850ug1.demon.co.uk -
dwightk.elvey＠amd.com -
rschaefe＠gcfn.org