Operation / Technical Manual
NORM-O-TEMP
®
, Model 111W
Page 62 of 82
6-17.1.
Ground Integrity
Using a Digital Multimeter, measure the resistance between an exposed, unpainted
part of the metal case of the NORM-O-TEMP
®
and the ground conductor of the
power plug. Take measurements between ground pin and the Hansen fittings, also
between the ground pin and the handle. Verify that the case to ground pin
resistance is less than 0.2 ohms.
6-17.2.
Leakage Current
Using an Electrical Safety Analyzer, measure electrical leakage current of the under
the following conditions: Power ON & OFF, polarity normal and reverse, unit
grounded and ungrounded. When measuring power ON, polarity normal and
reverse, measure when the NORM-O-TEMP
®
unit is heating and circulating water
(both the heater and pump are ON). When measuring power OFF, normal and
reverse polarity, measure while the NORM-O-TEMP
®
unit is going through self-
calibration, when it is first turned on (both the heater and pump are OFF). The
leakage current should be less than 500 microamps. If a NORM-O-TEMP
®
unit has
leakage current that exceeds the appropriate limit or has a significant increase in
leakage current, the cause should be investigated.
Excessive leakage current is most commonly caused by a defective heater, but other
components can also fail in such a way as to increase leakage current. To find the
source of excessive leakage current, suspect components should be sequentially
disconnected until the source of the high leakage current is isolated.
