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DATrig 21st January 2012 02:44 AM

RCM vacuum pump help.
I got my hands on a KNF pump for my DIY RCM based on the Loricraft. The pump has the same specs as the Loricraft KNF, but the wiring looks a little different and has me a little confused. I called KNF and talked to a nice guy who got in touch with Germany and found the wiring schematic, but the colors are off. There is a black and a red together, a black(thick) and black together, and a single red and single black(thick). There are 2 thick black wires and 2 thin. The capacitor is pretty easy to figure out.
Any help would be great.

M Gregg 21st January 2012 02:55 PM

I don't know whats the colours and check the components with a meter then look at the colours to give you a guide :)

You need to use a multimeter and find the two windings..first with ohms range.. then mark the wires(start and end) for winding 1 and 2..

The supply goes through the cap to the winding so find the will charge up on the meter and the ohms will climb to open circuit reverse it the same happens.. Then find the two windings that is a good start you may be able to link the colours to the diagram.

If the conection between the winding and the cap is inside the motor then you will read the aux winding and cap series resistance that will climb to infinity..

M. Gregg

M Gregg 21st January 2012 03:18 PM

This is close to what you appear to have,

Single Phase Induction Motor Control Theory | Circuit Diagram

You don't seem to have a start switch just an over temperature switch or CB..connecting the live L1 to the circuit..

The 2nd diagram is what you have (no switch)

M. Gregg

M Gregg 21st January 2012 03:32 PM

The two diagrams you have just show winding HP in reverse to change start direction.. :)

Both diagrams on your drawing are the same except for this change..

M. Gregg

DATrig 21st January 2012 04:03 PM

Thank you so much for your reply here is what I came up with. The capacitor is on the outside and is directly wired so it's separate and easy to deduce. I used my mm and this what I got.
Red Blk- 166.2
Red B/B- 166.2
Red R/B- 115.6
Blk B/B- 0.0
Blk R/B- 50.7
B/B R/B- 50.6

I'm sorry, but this still has me confused. I do understand The Circuit diagram you linked and that makes tons of sense, but can you help me correlate the two. Thanks again for your help.

M Gregg 21st January 2012 04:11 PM

Here is how to approach it..

Find your (Can't make out) if its an over temp or CB switch.. it will be short circuit..IE a closed switch find and connect that first from L1... then connect the cap to the correct connections.. then see how many connections you have left..

At a guess (it might not be)..the reversable winding may be single ends ie not connected to anything else,,

So get to this point first.. Could this be your switch/cb? Blk B/B- 0.0

The 166.2 is interesting at a guess these are the windings and the two connections on there own are the reversable winding
(Its difficult at a distance to do this so its at your own risk)

You could contact the guy who gave you the diagram and ask him to get the values of the windings..that would confirm it..

You only have 6 connections (I see you holding) so:
2 for each winding +4
2 for the CB/over temp..

M. Gregg

DATrig 21st January 2012 05:00 PM

I have stared at this for a while and reread everything. B/B and blk can't be a switch because that would leave me with red and r/b being my only wires left. The switch in my estimation is auxillary. B/B, Red, Black, and R/B would have to be HP and HF. 1.2 Motor/Stator with 4 strands 1.2.1 Without on-/off switch without backing up. If what I'm saying sounds like hogwash please feel free to let me know. I appreciate your help.

DATrig 21st January 2012 05:08 PM

I don't think B/B and blk are a switch because that would leave me with red and R/B. I believe the switch is auxillary. B/B,R/B,Red, and Black have to equal HF and HP in my estimation.
1.2. Motor/Stator with 4 strands.
1.2.1. Without on-/off switch, without backing up.
If this sounds like hogwash feel free to let me know. I appreciate your help.

sorry for the double post didn't realize the moderator needed review

M Gregg 21st January 2012 05:41 PM

What you say sounds reasonable,

I guess the wires connected togeather may give a clue..

Can you get any more information regards windings resistance from manufacturer?

This would be a way to ensure no mistakes are made..

If you can't get any more info I guess you are going to have to go for best guess...

M. Gregg

M Gregg 21st January 2012 05:46 PM

The six connections you are holding..

Do these include the capacitor?

M. Gregg

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