# Peco PL-11 problem



## Featherbedder (Jun 29, 2014)

I just got 4 new PL-11 Peco turnout motors. So far 3 of them have been tried and they move fine in one direction but very weak in the other. They will move the turnout in one direction but not the other. I have them hooked into the same power panel as my other 4 older PL-11 turnout motors, they all are still working fine. I am using Atlas turnout switches, have tried 2 different switches with the same results both times.
I am now wondering if Peco had a bad batch of turnout motors. Has anyone else had this problem? Any suggestions on what else I could try to solve the problem?
Thanks, John


----------



## DonR (Oct 18, 2012)

Have you rechecked the solder connections?

I have had problems with the solder terminals on the PL11s. They
don't seem to take solder as well as most other materials. This
has resulted in cold solder joints beyond what
could be expected. Well, actually none should be expected.

If those are OK, use your volt/ohmeter and check the coil resistances.
They should all be the same. Any difference and you have
a Mfgrs. problem.

Don


----------



## Featherbedder (Jun 29, 2014)

Thanks for the suggestion, Don. I measured the coil resistance on all 3 of the turnout motors that I have tried. One side reads 4 ohms the other reads 8. On the older ones that I have been using for a while, and still work, the reading is 4 ohms on both coils. Looks like a Mfg. problem. Guess I will be calling Model Train Stuff on Monday.
John


----------



## Featherbedder (Jun 29, 2014)

DonR
I worked for over 35 years solving machine problem, both mechanical and electrical. The fact that one side of the turnout motor equaled twice that of the other side told me that I was wired wrong. I ignored my memory of the ones I had installed about a year ago and checked the instructions, guess what, that was the problem. The turnout motors are working fine now.
If you had not suggested measuring the resistance I would probably not have thought about that. 
Thanks again. This forum is a great resource.
John


----------



## DonR (Oct 18, 2012)

John

It's not clear how your PL11s were wired wrong to
cause that difference in resistance.

Be interesting to know.

Don


----------



## fcwilt (Sep 27, 2013)

If his are like mine then the two coils have a common connection, let's call that COM.

Then each coil has it's own other connection, let's call them C1 and C2.

Measuring from the COM connection to either C1 or C2 would measure the resistance of one coil.

But measuring from C1 to C2 would measure the resistance of both coils.

Now in theory if both coils were perfectly matched applying power across C1 and C2 would not move anything because the coils are trying to move the points in the opposite direction.

But if the coils were slightly different, then one might slightly overpower the other and still move the points.

However it would seem to me that, if this is true, the direction moved would depend on which coil just happened to be more "powerful".

Never actually did this myself but I'm tempted to go test a batch to see what happens.


----------



## Featherbedder (Jun 29, 2014)

One measurement, 8 ohm, was across the whole coil. The other measurement, 4 ohm, was from the center tap to the outside.


----------



## DonR (Oct 18, 2012)

So are you now saying you have the common tabs connected
to your power source (-) and the two end tabs connected to
their specific buttons from (+) and all is well?

Don


----------



## Featherbedder (Jun 29, 2014)

Yes, all is well. I have two of the 4 new motors in and working. Two more turnouts and motors to install yet. Sure love the new Digitrax Zephyr Xtra, my first DCC. May add the computer control later. That looks interesting.
John


----------

