terminals and support so that air gaps of several millimeters
inches exist between bare conductors and ground. Clean and dry
cable sheaths, for a distance of 305 mm one foot from ends of
cables and exposed insulation at ends of cables. Connect ends of
both conductors of the circuit together and to high-voltage
terminals of test equipment, and apply test voltage specified in
the following tabulation between conductors and ground for a
period of 5 minutes.
Test Voltage, dc
First Test
Test on
Series
on New
Existing
Lighting Circuits
Circuits
Circuits
High intensity series
lighting circuits
(5000-volt leads,
500- and 200-watt
9000
5000
Medium intensity
series lighting
circuits (5000-volt
leads, 30/45-watt
6000
3000
600-volt circuits
1800
600
When additions are made to existing circuits, test only new
sections in accordance with "First Test on New Circuits" in table
above. [To ensure reliable operation, test complete circuit at
reduced voltages indicated above.]
b.
Leakage Current: Measure and record insulation leakage current in
microamperes for each circuit for each minute application of test
voltage. Do not exceed the value of the insulation leakage
current calculated on the basis of the following leakage current
allowances for cable and connected equipment for each circuit:
(1)
3 microamperes for each 305 meters 1000 feet of cable.
(2) 2 microamperes for each 200-watt and each 500-watt 5000-volt
series transformer.
(3) 2 microamperes for each 30/45-watt 5000-volt series
transformer.
Note: The above values include allowances for the normal number
of connectors and splices.
If measured value of insulation leakage current exceeds calculated
value, sectionalize the circuit and repeat specified test for each
section. Locate defective components and repair or replace until
repeated tests indicate an acceptable value of leakage current for
the entire circuit.
SECTION 16522N
Page 41
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