Re: Cap Start Motor

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Hi Jim,

The motor was advertised as a cap start.  In fact, I have seen no cap run
motors on ebay in the 1/3 and lower HP range.  Yes, I have emailed Franklin
Electric and still waiting for a reply.  I do think I'm making progress
though, I now believe the WHITE wire is the common wire and should be
connected to LINE NEUTRAL.  This will in effect let the start winding be
separate from the main winding.

My current theory is that the BROWN and WHITE wires connect to the main
winding, the internal RED and WHITE wires connect to the start winding, and
the external BLACK and RED wires go to a start cap (143 uf on the name
plate).  BROWN, being hot, goes thru the SWITCH to the external BLACK wire
and to the cap.  The external RED wire, coming from the other side of the
cap returns, goes thru the switch, and connects to the internal RED wire
connected to the start winding.

I hooked it up this way and the motor runs.  The motor quickly got warm as I
think the start switch is defective.  The BLACK path thru the switch was
open all the time and it was clear nothing would ever work that way so I
jumpered it.  The RED path thru the switch never opens (like a good start
switch should) so the start winding is never disconnected hence the
overheating.

Disaster then happened.  My power cord (plugged into the variac) to motor
connection accidently shorted with the variac dial set to zero and the
variac when up in smoke.  I took the variac apart (one of these "NEW RED"
ones bought on ebay from Canada and made in China) and found that the input
LINE NEUTRAL and LINE HOT were wired up backwards.  The circuit breaker was
in the NEUTRAL path and when the setting was zero, both of the LINE NEUTRAL
and LINE HOT outputs were HOT.  The short must have been to SAFETY GROUND
and the circuit breaker did not protect.   So, we all need to beware!!!

One of those days,
Gerry R.


 > Original poster: Jim Lux <jimlux-at-earthlink-dot-net>
 >
 > At 08:17 AM 5/7/2004 -0600, you wrote:
 > >Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>
 > >Hi all,
 > >
 > >I just received a Franklin Electric 1/12 HP cap start motor today that I
 > >got off of ebay and it came with no wiring diagram.  There are four wires
 > >from the motor (a RED(in) and BLACK(in) pair, and a BROWN and WHITE
 > >pair).  The wart on top of the motor encases a switch looking device and
 > >not the start cap that I was expecting (of course I have no hands on
 > >experience with cap start motors).  Apparently the start cap is something
 > >I supply???  The RED(in) and BLACK(in) pair goes into this switch looking
 > >device and I presume that the downstream side (a RED(out) and BLACK(out)
 > >pair) of this device is the start winding.  The WHITE and BROWN pair must
 > >then be the main winding.  The two windings are not seperate, but share a
 > >common node (ie, BROWN and BLACK(out) are connected).  The resistance
 > >between WHITE and BROWN is 11 ohms and the resistance between RED(out)
and
 > >BLACK(out) is 17 ohms.  The resistance between RED(out) and WHITE is 6
 > >ohms that makes me believe that this is a tapped winding.
 > >
 > >If this is the case, RED(out) would be the outer tap (wrt, the common
 > >node) and WHITE would be the inner tap.
 > >
 > >Could someone tell me if I have this correct that RED(out) and BLACK(out)
 > >is the start winding and WHITE and BROWN (same as BLACK(out)) comprises
 > >the main winding?  This is also a thermal protected motor and I don't
know
 > >if this wart is related to thermal protection and the start winding
switch
 > >is internal or the other way around.  All pictures of cap start motors on
 > >ebay seem to have this wart.
 > >
 > >Also, is it customary that the start cap NOT be part of the motor?
 > >
 > >In addition, the name plate for the motor has the following:
 > >
 > >Model 1106680404
 > >1725/1450 rpm
 > >Date code K88
 > >
 > >Many thanks,
 > >Gerry R
 >
 > Sure it's a cap start and not a PSC (cap run) motor?  Have you sent an
 > email to Franklin Electric to ask them for a wiring diagram?  Sure, the
 > motor might be 15 years old, but it's not like they change designs that
often.
 >
 > http://www.franklin-electric-dot-com/empd/tech/fe-basic.html
 >
 >
 >
 >
 >