Sciencemadness Discussion Board

Chemical Feed Pump Questions

submachine - 5-9-2012 at 01:18

I aquired a chemical feed pump, a Precision Control Products Corp of Waltham Mass model# 12011-11.

It is rated @ 115v 2.0amp 50/90hz. This came out of a warehouse I demolished.

I tried a 115v/3 prong rotary(?) style plug, and even a 220v plug but neither were a fit. I am hoping that it might be some type of variac style plug, which I have never seen/used one, so was hoping someone here might have.

Pump is missing its foot valve, currently trying to source a replacement. Front dial I assume could just use a screw(piston limit or bleed), and a rubber stopper for the top prime/blowoff port.

Would really like to test this, and was hoping for help on the plug before I rewire it.



Here is a very similar one on eBay, which answered my other questions. So I updated this post accordingly, it appears to use a standard US style plug.

http://www.ebay.com/itm/Vintage-Chemical-Pump-Precision-Chem...

[Edited on 5-9-2012 by submachine]

watson.fawkes - 5-9-2012 at 04:53

Quote: Originally posted by submachine  
The plug on this unit is definately not something I am familiar with. I tried a 115v/3 prong rotary(?) style plug, and even a 220v plug but neither were a fit. I am hoping that it might be some type of variac style plug, which I have never seen/used one, so was hoping someone here might have
It's some kind of NEMA locking plug. The thing it matches best is L12-20P, which 3-phase 480V. My guess is that it's a non-standard wiring matching a non-standard receptacle. Just replace it. Given that it's non-standard, you'll have to use color-coding on the wires in the power cable to determine what hot, neutral, and ground are.

submachine - 5-9-2012 at 06:04

Quote: Originally posted by watson.fawkes  
Quote: Originally posted by submachine  
The plug on this unit is definately not something I am familiar with. I tried a 115v/3 prong rotary(?) style plug, and even a 220v plug but neither were a fit. I am hoping that it might be some type of variac style plug, which I have never seen/used one, so was hoping someone here might have
It's some kind of NEMA locking plug. The thing it matches best is L12-20P, which 3-phase 480V. My guess is that it's a non-standard wiring matching a non-standard receptacle. Just replace it. Given that it's non-standard, you'll have to use color-coding on the wires in the power cable to determine what hot, neutral, and ground are.


Thank you very much!

I pulled the face plate, and looks like you are correct. It has x and y next to two of the connectors, which seems how NEMA denotes some of its plug connections. There are black/brown/ green wires, with heavy green oxidation on the black/brown connectors. With little to no oxidation on the green or sligthly L shaped connector. Did a google search on wiring guides, this doesn't really fit the mold for any I can tell. About 99% sure green is Ground. :D

So 50/50 chance of being correct for Brn/Blk. Some of the guides equate a brown to what black would normally be color coded for. I'm thinking Brown(hot)/Black(Neutral), wikipedia says this is the norm for down under(not that I trust wiki). Gonna keep up the search, see if my odds will improve. If anyone has any more help in the mean time, would definately be appreciated.

[Edited on 5-9-2012 by submachine]

watson.fawkes - 5-9-2012 at 09:01

Quote: Originally posted by submachine  
There are black/brown/ green wires, with heavy green oxidation on the black/brown connectors. With little to no oxidation on the green or sligthly L shaped connector.
[...]
So 50/50 chance of being correct for Brn/Blk. Some of the guides equate a brown to what black would normally be color coded for.
Get out an ohmmeter. The safety ground should be simply a parallel conductor to the neutral. You should see a resistance difference between ground-neutral and ground-hot.

submachine - 5-9-2012 at 09:42

Quote: Originally posted by watson.fawkes  

Get out an ohmmeter. The safety ground should be simply a parallel conductor to the neutral. You should see a resistance difference between ground-neutral and ground-hot.


I see the logic in that, unfortunately this POS multimeter from Harbor Freight isn't registering a reading from brn/grn or blk/grn. I did get a reading across brn/blk. Will have to go into my moving boxes and find my "good" circa 70's multimeter. I'm going with the assumption that a lower resistance should be attained at neutral\ground. Thanks.

watson.fawkes - 5-9-2012 at 10:52

Quote: Originally posted by submachine  
I see the logic in that, unfortunately this POS multimeter from Harbor Freight isn't registering a reading from brn/grn or blk/grn. I did get a reading across brn/blk.
Even a crappy meter should detect what ought to be a short, just a few ohms at most. The safety ground wire might not be connected inside the junction box on the motor, or it might have opened inside the cable. If they used a nonstandard plug and receptacle, they might not have hooked up the ground correctly. The next thing to do is to open up the junction box at the motor. Check resistances at the terminals there. Also check conductivity of the individual wires in the power cable.

zed - 11-9-2012 at 12:50

A while back, I acquired a brand new, air-motor powered, chemical feed pump...... for a paltry $70.00 U.S., via e-bay.

This included the whole assembly, air motor, feed pump, and mounting plate. Quite heavy.

Sometimes, very expensive equipment, in new condition, goes unnoticed and sells cheaply. I couldn't have purchased the air-motor for that price, even on e-bay.

All things being equal, if you intend to pump anything more flammable than water, it might be prudent to sell that electric unit, and replace it with something explosion-proof. Something air powered. This requires that you supply compressed air from a remotely located compressor, which is a pain. It does however, reduce considerably, the possibility of fires and explosions.