"Trevor" wrote in message
news
On Sun, 18 Apr 2004 16:58:52 -0400, NetMax wrote:



I built my own delay-off timer, and I'd be glad to share the
directions
and schematic, but it's not your average DIY job. I used 3
electrical
junction boxes, #1 had a GFI outlet for the equipment, #2 had a
standard
delay-on timer and #3 had a 120Vac DPDT relay which I wired into the
delay-on timer.


Thanks Netmax I would appreciate it if you could do that. I would not
be
attempting to build it myself - I have some friends are are electric
whizzes. Either post here if you feel its appropriate or I will email
you
off list as I do not include my real email in my posts for obvious
reasons.

Thanks also to Jtechs offer to build me one but I fear it would not
work
as I am in South Africa and we have 220 or 240 volts and then there is
still shipping.

Trev

No problemo. hmmm, 230Vac eh? I think (but you should check with your
whiz friends to make sure) that your 3 wire circuits are 230Vac hot, a
neutral and a chassis ground (if a third wire is used), going by the 15A
BS-5733 standard. North America's 220Vac is different and wouldn't work.
Is this what you use?
http://www.interpower.com/scripts/ws...a/South+Africa
I thought S.Africa also used a Euro standard in some regions. My
directions won't be specific to pin number.

I'll do a quick text description now, off a schematic I just drew on a
napkin ;~). If you need it graphical, email me with 'NetMax' in the
subject line, and I'll draw something for you, or I can always post to
alt.binarie.aquaria.

Parts needed:
1) Dial timer (receptacle or plug-in), rated for 230Vac and the
accessory's current load.
2) Power bar (where you will be plugging your filters and heaters).
3) A relay, must have a 230Vac rated coil (typically 250V or more), and
be DPDT (double pole double throw). An SPDT would work as well, but is
not as good as it only interrupts one side (and you better hope you
interrupted the 'hot' side and not the 'neutral' side ;~). Relay must be
rated for the current you are switching. Ideally it has the same rating
as your house circuit (15A?).
4) Receptacle driving this contraption should be GFI (GFCI) as is normal
for all aquarium accessories.
5) Receptacle which you will be plugging your power bar into. If the
receptacle driving the contraption is not GFI, then make sure this one is
GFI, and properly grounded.
6) Electrical box(es) to enclose #1 (if receptacle model), #3 and its
wiring, and #5).

Convention
Plug has metal pins. Socket or receptacle accepts plug. Hot is 230Vac
live. Neutral, neut or rtn is an AC return. Gnd is ground, safety
ground or chassis ground.

Connections
1) Dial timer
a -plug hot
b -plug neut
c -gnd in
d -socket hot
e -socket neut
f -gnd out

2) Power bar
standard 3 pin plug

3) DPDT Relay
a -coil +
b -coil rtn
c -line 1 comm
d -line 1 NO
e -line 1 NC
f -line 2 comm
g -line 2 NO
h -line 2 NC

4) Standard receptacle (house)
a -socket hot
b -socket neu
c -socket gnd

5) Receptacle for power bar
a -plug hot
b -plug neu
c -plug gnd

Still with me? ;~) With text descriptions, all the work is behind us
now.

Connect as follows:

Timer IN
4a-1a
4b-1b
4c-1c

Timer OUT
1d-3a
1e-3b
1f-5c

Relay IN
4a-3c
4b-3f

Relay OUT
3e-5a
3h-5b

If your relay has a chassis/safety gnd connection (they usually don't),
then it gets star'ed with the electrical boxes to 4c. For a quick
graphical view, print this page and connect the dots.

That should work, your power bar will always be on, except when you turn
the timer, for that set time....unless that was a coffee stain on my
napkin ;~)

You know the usual disclaimers. I take no responsibility bla bla etc
etc. It's not rocket science, but electrical wiring does have to be done
to code.
NetMax