thunderfvck - 22-3-2004 at 11:38
Okay, I recently got a vacuum pump on ebay for pretty cheap. The problem is it DOESN'T HAVE A PLUG! It just has the wires and the ground.
So I ask, can I attach any standard plug?
The vacuum pump reads, 115 VAC, 60 Hz, 1.5 A.
The plug I have says 125 V and 10 A and has a ground.
Do I risk destroying my precious pump, or does it somehow work out what it needs (and spits out the rest) internally?
How would I go about attaching this? I was thinking of simply tying the wires together, but I have noticed in my past electricity endeavors that this
has caused some of the wires to burn. I don't want this. Not on this baby. I don't know, maybe if I tied it around nice and long, it'd
be okay. Anyways, before I start getting crazy I'd like to hear any of your suggestions.
Thanks
Haggis - 22-3-2004 at 11:51
You should be fine. You have, coming out, a hot, a neutral, and a ground. Black, white, then green for ground usually.
On your plug, there are three prongs. Two flat and wide prongs, the hot and neutral, then a round cylindrical one which is ground. The hot gets
screwed into one prong, and the neutral goes into the other. Then, ground is attached to the ground spot.
It is pretty simple, just make sure the wires don't touch eachother.
thunderfvck - 22-3-2004 at 12:35
Alright!
It's all done and it works quite nicely! THe wires don't heat up or anything, I just tied them around eachother. The plug has copper wires
while the pump has silvery wires. This isn't a problem, right?
The pump seems to get warm after using it for like 5 minutes. Is this normal?
Sorry for my stupid questions, I'm just paranoid. I don't want my pump dying on me.
Another problem I am having is choosing the right kind of tubing to use. Is this really critical? Or will pretty much any solid tube suffice?
[Edited on 22-3-2004 by thunderfvck]
Haggis - 22-3-2004 at 14:25
1) The color difference in wires isn't a big deal. However, I would have used wire nuts to secure the connection, those plastic cone like
objects that you see electrical house wiring connected with. If you want to keep it tied up, I would solder it. Failing that, make sure that the
wires won't pull apart.
2) Pumps do get warm. They will, however, get even warmer if you have the inlet blocked somehow where it cannot get any air. Don't let this
happen.
3)Depending on what you're using the pump for, different tubing will work. If you are using your pump as a bubbler, then something like amber
tubing will suffice for the outlet. If you are using it as a vaccuum, and the hose is connected to the inlet, you should have a strong rubber vaccuum
hose. If you cannot mash it together with your fingers, and it stays somewhat rigid, you should be fine.
Uhhhh...
Turel - 22-3-2004 at 14:42
Green is negative. Black is (almost) always ground. Red = pos Green = neg Black = ground.
Black can be negative as well if ground is negative, such as in automobiles and simple 'dumb circuits' common around the house.
unionised - 22-3-2004 at 15:01
It's a vacuum pump so it is designed to work perfectly well with the inlet blocked (in fact, that is the condition under which it has least work
to do).
Turel, are you joking?
I'm not too familliar with the US convention for colour coding wires, but I wouldn't trust anyone who talks about positive and negative on
an AC circuit.
As I recall, it should be Green for ground, white for live and black for neutral.
thunderfvck - 22-3-2004 at 15:21
I just tied up the wires and put electrical tape around them. Seems pretty secure to me. Works like a charm. Besides, I don't plan on pulling the
cord to test its strength or anything, so I think what I did will suffice. ALthough it DOES look a tad ugly, but whatever. You should see my retort
stands.
Hahaha
Turel - 22-3-2004 at 15:22
That's funny that you say you would not trust me. I fix electronic equipment as my profession. 
The color conventions must indeed be different depending on country.
You are not looking at the entire circuit. It does not go straight from the plug to the pump coils. It first gets recified, filtered and regulated to
a static bus voltage, which from there gets used. This is for safety and to prevent brownouts.
Cheaper electronic devices do not use dipolar full bridge rectifiers, instead opting for cheaper designs that only work for one set of polarity. You
can notice these devices easily as they will have to be inserted into a socket only one way (asymmetrical size plug prongs prevents inserting it
backwards) so as to charge the rectifier properly.
In theory a half wave rectifier should operate properly is inserted with reversed polarity into an AC socket, but they use this convention for safety
regulations nonetheless.
[Edited on 22-3-2004 by Turel]