Xylem BMAID R4 - Manual (Page 36)

PAGE 36
Residential Water Systems
CentriPro
motor wINDING rESIStaNCE ChECkout CablE ChECkout
Checking Cable and Splice
1. Submerge cable and splice in steel barrel of water
with both ends out of water.
2. Set ohmmeter selector on RX100K and adjust
needle to zero (0) by clipping ohmmeter leads
together.
3. After adjusting ohmmeter, clip one ohmmeter
lead to barrel and the other to each cable lead
individually, as shown.
4. If the needle deflects to zero (0) on any of the cable
leads, pull the splice up out of the water. If the
needle falls back to
(∞) (no reading) the
leak is in the splice.
5. If leak is not in the
splice, pull the cable
out of the water slowly
until needle falls back
to (∞) (no reading).
When the needle falls
back, the leak is at
that point.
6. If the cable or splice
is bad, it should be
repaired or replaced.
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, the leads are mixed.
measuring winding resistance
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 as
described earlier on page 11.
open master breaker and
disconnect all leads from
control box to pressure switch (q-D type
control, remove lid) to avoid damage to meter
or electric shock hazard.
2. Connect the ohmmeter leads as shown below.
tablE 2 – Cable resistance – Copper
Cable DC resistance of Cable per 100 foot
Size length ohms per pair of leads
14 .544
12 .338
10 .214
8 .135
6 .082
4 .052
2 .032
If aluminum cable is used the readings will be
higher. Divide the ohm readings on this chart
by 0.61 to
determine the
actual resistance
of aluminum
cable.
See motor data pages
for motor resistance
ratings.
RULE OF THUMB
Add resistance of drop cable when checking
pump in well. See Table 2 above.
CAUTION
Checking Cable and
Splice Test
Attach this lead
to Metal Tank
Ohmmeter
Set at R x 100K
OHMS
R x 1000
R x 10K
R x 100K
R x 100
R x 10
R x 1
ZERO
OHMS