Electrical Schematic

PAGE 7
LANCASTER HYDRO-FORCE
2-Wire & 3-Wire
Motor Tests
TM
L1 L2 R Y B
L1
GROUND
L2
TO
POWER
SUPPLY
POWER SUPPLY
MUST BE
SHUT OFF
GROUND
RED
YELLOW
BLACK
BLACK
YELLOW
RED
TO
PUMP
MOTOR
OHMMETER SET AT R X 1
Procedure-
1) WARNING! MAKE SURE POWER IS TURNED OFF! Open (turn off) master breaker
and disconnect all motor leads from control box (3-wire motor installation) or pressure
switch (2-wire motor installation).
QUICK-DISCONNECT DESIGN
3-WIRE CONTROL BOX
WITH LID REMOVED
TO
PRESSURE
SWITCH
2) Use an ohmmeter with the scale lever set to R x 1 for values under 10 ohms. For values
over 10 ohms, set the scale lever to R x 10. Short the meter leads together and turn the
3) On 2-wire motors, measure the main winding resistance from line-to-line by connecting the
ohmmeter between the two motor leads.
Test result (what it means)-
1) Correct readings should be equal to the winding resistance values from the charts on the
OPERATING DATA PAGE for a given motor, plus the resistance of the drop cable from the
DC Resistance (ohms) per 100 feet of Copper Cable (two leads) at 50 °F
AWG Cable Size
Winding Resistance Test:
This chart shows the total resistance of copper cable from ohmmeter to motor and back (round trip).
If aluminum conductor cable is used, the resistance will be higher... divide ohms from this chart by 0.61 for aluminum cable resistance.
meter's adjustment dial to "zero" the meter.
On 3-wire motors, measure the main winding resistance (yellow to black) and the start
winding resistance (yellow to red) by connecting the ohmmeter between the two motor leads
described.
Ohms
14
0.544
12
0.338
10
0.214
8
0.135
6
0.082
following table...
2) Conditions:
A) If any one ohm value is less than specified, that motor winding is shorted.
B) If any one ohm value is greater than specified, that motor winding or the cable is open,
or there is a poor cable joint or connection.
C) On 3-wire, if one ohm value is greater than specified and one ohm value less than
specified, the leads are mixed. Refer to "Identify Cable Leads" section of this bulletin.