Xylem GSSERVICE R2 Service Manual Submersible Pumps & Jet Pumps - Manual (Page 37)

MO
TOR INSULA
TION RESIS
TANCE
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 Ohms Megohm
Value Value
A new motor (without drop cable). 20,000,000 20.0
(or more)
A used motor which can be 10,000,000 10.0
reinstalled in the well. (or more)
New motor in the well 2,000,000 2.0
(or more) (or more)
Motor in the well in good condition 500,000 –
2,000,000 0.5 – 2.0
Insulation damage, locate and repair Less than Less than
500,000 .50
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.
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