Insulation And Winding Resistance Tests - Xylem CentriPro AQUAVAR SOLO2 Manual De Instalación

8: INSULATION AND WINDING
8: INSULATION AND WINDING
RESISTANCE TESTS
RESISTANCE TESTS
INSULATION RESISTANCE
Electrocution Hazard. Turn off power and
DANGER
wait 5 minutes before opening cover.
1. Set the scale lever to R x 100K and adjust to 0.
2. Disconnect motor leads from controller (note position
of wires). Connect an ohmmeter lead to any one of the
motor leads and the other to the metal drop pipe. If the
drop pipe is plastic, connect the ohmmeter lead to the
metal well casing or ground wire.
Normal Ohm and Megohm Values (Insulation
Resistance) Between All Leads and Ground
Insulation resistance does not vary with rating. All
motors of all HP , voltage and phase rating have similar
values of insulation resistance.
Condition of Motor and Leads
A new motor (without drop cable).
A used motor which can be
reinstalled in the well.
New motor in the well
Motor in the well in good condition
Insulation damage, locate and repair
Drop
Cable
with
Ground
Wire
What it Means
1. If the ohm value is normal, the motor windings are not
grounded and the cable insulation is not damaged.
2. If the ohm value is below normal, either the 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.
Ohms Megohm
Value Value
20,000,000 20.0
(or more)
10,000,000 10.0
(or more)
2,000,000 2.0
(or more) (or more)
500,000 –
2,000,000 0.5 – 2.0
Less than Less than
500,000 .50
OHMS
ZERO
OHMS
R x 100
R x 1000
R x 100K R x 10 R x 10K
R x 1 R x 100K
MOTOR WINDING RESISTANCE CHECKOUT
1. Set the scale lever to R x 1 for values under 10 ohms.
For values over 10 ohms, set the scale lever to R x 10.
Zero balance the ohmmeter.
Electrocution Hazard. Turn off power
DANGER
and wait 5 minutes before opening cover.
2. Connect the ohmmeter leads as shown below.
Cable Resistance – Copper
If aluminum cable is used the readings
Paired Wire
Size
will be higher. Divide the ohm readings
Resistance
Cable
on this chart by 0.61 to determine the
(ohms per foot)
actual resistance of aluminum cable.
14 .0050
12 .0032
Ground
10 .0020
Wire
8 .0013
6 .0008
4 .0005
2 .0003
0 .0002
00 .00015
000 .00013
0000 .00010
See motor data pages for motor resistance ratings.
What it Means
1. If all ohm values are normal, the motor windings are
neither shorted nor open, and the cable colors are
correct.
2. If any one ohm value is less than normal, the motor is
shorted.
3. If any one ohm value is greater than normal, the
winding or the cable is open or there is a poor cable
joint or connection.
4. If some ohm values are greater than normal and some
less and the motor is single phase with red, black and
yellow wires, then the leads are mixed.
O H M S
Z E R O
O H M S
R X 1 0 0 R X 1 0 0 0
R X 1 0 R X 1 0 K
R X 1 R X 1 0 0 K
Motor
Leads
RX 1
or
RX10
19