ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Kichler Lighting Recalls Pendant Lights
by Admin - 09/18/19 08:47 PM
Does a 'normal 3ph-AC motor' include capacitors?
by gfretwell - 09/18/19 01:20 AM
Another weird NEC code question on Feeder Taps
by gfretwell - 09/18/19 01:14 AM
NEC 2017_392.22(B)(1)(b)
_What's the smallest width

by Bill Addiss - 09/17/19 07:13 PM
NEC Question_Cord-&-Plug EGC shorter then Neutral
by pcsailor - 09/16/19 05:26 AM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
2 registered members (Admin, gfretwell), 11 guests, and 11 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
How to connect Motor #192423 02/13/10 01:45 AM
Joined: Feb 2010
Posts: 2
fixit100 Offline OP
New Member
Motor is for church. Blower on heat exchanger. Fire destroyed leads to motor and need to know which wire goes where to reconnect. Motor is good. Replacement motor runs to fast. I am attaching a file with the motor info that I know.

Attached Files drawing.JPG
Work Gear for Electricians and the Trades
Re: How to connect Motor [Re: fixit100] #192450 02/14/10 12:39 PM
Joined: Feb 2008
Posts: 165
Rewire Offline

Re: How to connect Motor [Re: Rewire] #192467 02/15/10 12:59 PM
Joined: Feb 2010
Posts: 2
fixit100 Offline OP
New Member
Thanks for the info, but that web site really doesn't help me. This motor only has 4 leads. I am pretty sure this is a PSC type motor, and as you can see from the name plate it can be wired for high and low voltage. It was used with an autotransformer for speed control, but all the wiring was removed before I seen it. I need to know if both windings are connected to the speed control and which ends. I sort of think booth windings would be connected in parallel, since I pretty sure they be in series for hight voltage. It was used on 120 v.
Thanks fixit100

Re: How to connect Motor [Re: fixit100] #192471 02/15/10 03:54 PM
Joined: Dec 2000
Posts: 4,281
electure Offline

Have you been to Scott35's "Technical Reference Area" on this forum?

He's got schematics for all kinds of motors there.

Re: How to connect Motor [Re: electure] #192691 02/25/10 04:28 PM
Joined: Jun 2007
Posts: 301
JValdes Offline
I cannot read the nameplate. Please write out the specs on it.

Re: How to connect Motor [Re: JValdes] #192696 02/25/10 09:03 PM
Joined: Mar 2005
Posts: 1,803
Alan Belson Offline
Q1. If it's not wired, how do you know the motor is good?

Assuming this is a [serviceable] fractional [1/6HP] psc. [?] :-

850prm on the plate means it has 8 poles, an expensive to replace item [Baldor $600+]. And explains why the replacement ran too fast.
[Motor rpm = 120 x hz / no of poles.]

Winding A-B is the run winding.

Winding C-D is a start winding, [you can see the capacitor between slots 16 and 34 in your drawing].

The wiring is simple. Take 120v 60hz to a link fitted between C and A.
Fit a link between D and B and connect to the other side of 120V 60hz. Fit a switch connection and try a quick blip to see if it starts. Take care not to prolong the current if all you get is a buzzz!! No start? The capacitor may be duff.
About 5uf would be the approx cap size for this size motor, if the markings on the original are unclear.
Now all you need to see is if it spins CW or CCW for your application. Some pscs can be reversed.

Good luck. Let us know if and when you've let the smoke out!! sick

Wood work but can't!
Re: How to connect Motor [Re: Alan Belson] #192697 02/25/10 09:32 PM
Joined: Feb 2003
Posts: 939
frenchelectrican Offline
One thing I can able read the name plate most of it anyway here it is.

1/5 CV { HP }
850 T/ Min { RPM }
60 HZ
110 volts @ 1.8 A
220 volts @ .9 A

so I am pretty sure this is a dual voltage PSC connected motour and I am thinking the 4 leads are for changing voltage on the motour so you have A B C D marking so A et B is one set of coil while C et D is on other set of coil so to order to run this in 120 volt format you need bring L1 with A et C then netural will be B et D that should work only if le capaitor is permament connected inside of the windings.


Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Re: How to connect Motor [Re: frenchelectrican] #192724 02/27/10 12:34 PM
Joined: Nov 2007
Posts: 763
KJay Offline
Holy cow, you guys have way better eyes than I do.
I can't even make out that nameplate data or pic when I zoom in on it. frown

Re: How to connect Motor [Re: KJay] #192736 02/27/10 09:27 PM
Joined: Oct 2000
Posts: 2,720
Scott35 Offline
Broom Pusher and


Let us know if and when you've let the smoke out!! sick



Connect the new Motor for a 120V connection, then run it from the Autotransformer you had mentioned, as described below:

  1. Connect one Motor lead to the Autotransformer's output.
  2. Connect the Ungrounded Conductor of the 120V input Circuit to the desired tap on the Autotransformer.
  3. Connect the Grounded "Neutral" Conductor of the 120V input Circuit to the "Common" connection point of the Motor's Windings.

Refer to this drawing for details:

[Linked Image]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Re: How to connect Motor [Re: Scott35] #192812 03/04/10 04:42 AM
Joined: Oct 2000
Posts: 2,720
Scott35 Offline
Broom Pusher and

What's the status of this Motor scenario, Fixit?


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!


2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Bill Addiss
Bill Addiss
Posts: 3,923
Joined: October 2000
Show All Member Profiles 
Top Posters(30 Days)
Admin 6
Popular Topics(Views)
258,626 Are you busy
194,220 Re: Forum
183,690 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3