Electrical Schematic

PAGE 6
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
"MEGGER" MEGOHMMETER
INSULATION TESTER
OR
OHMMETER SET AT R X 100K
ATTACH THIS METER LEAD TO GROUND:
A) IF MOTOR IS OUT OF WATER, ATTACH THIS METER LEAD TO MOTOR FRAME.
B) IF MOTOR IS INSTALLED IN WATER, ATTACH THIS METER LEAD TO METAL WELL CASING (IF SUBMERGED),
METAL DROP PIPE, MOTOR GROUND LEAD, OR AN EXTRA WIRE EXTENDING INTO THE GROUND WATER.
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 a megohmmeter or an ohmmeter with the scale lever set to R x 100K (R x 100,000).
Short the meter leads together and "zero" the ohmmeter using the meter's adjustment dial.
3) Connect one meter lead to any one of the motor leads and the other meter lead to
ground. See diagram...
Test result (what it means)-
1) If the ohms value is normal, the motor is not grounded and the cable insulation is not
damaged.
2) If the ohms value is below normal, either the motor windings are grounded or the cable
insulation is damaged. Check the cable at the well seal as the insulation is sometimes
damaged by being pinched. Refer to "Checking Cable and Splice" section of this bulletin.
NORMAL OHM AND MEGOHM VALUES (INSULATION RESISTANCE) BETWEEN ALL LEADS AND GROUND.
CONDITION OF MOTOR AND LEADS OHMS VALUE MEGOHMS VALUE
MOTOR IN WELL. READINGS ARE FOR DROP CABLE PLUS MOTOR.
A new motor (without drop cable).
A used motor which can be reinstalled in well.
New motor.
Motor in good condition.
Insulation damage; locate and repair.
Insulation Resistance (Ground) Test:
200,000,000 (or more) 200.0 (or more)
10,000,000 (or more) 10.0 (or more)
2,000,000 (or more)
500,000 - 2,000,000
Less than 500,000
2.0 (or more)
0.50 - 2.0
Less than 0.50
Insulation resistance varies very little with rating. All motors, regardless of HP, voltage and phase rating have similar values of insulation resistance.
The table above is based on readings taken with a Fluke 1503 Insulation Tester using 500 VDC output test voltage.