FED-STD-228A
Method 6211.1
18 APRIL 2014
INSULATION DEFECTS, SPARK TEST
1. SCOPE
1.1 This method is intended for use in detecting defects in the insulation of insulated wires and cables.
Presence of a weak spot in the insulation results in a breakdown at that spot. When breakdown occurs,
the spark test equipment is arranged to either automatically stop the coiling equipment or produce a
visible or audible signal. From the manufacturer's viewpoint this method is preferred to the immersion
test method as it constitutes a continuous test that can be used at any time after vulcanization of the
insulation. It is, in effect, instantaneous, whereas the standard voltage withstand test and insulation
resistance test require the immersion of the wire in water for a minimum period of 12 hours. It is not
intended that the spark test completely replace the voltage withstand test and insulation resistance test.
The method is applicable to single conductor wire or cable size No. 6 AWG and smaller.
2. SPECIMEN
2.1 Unless otherwise specified, the specimen should be the entire length of wire or cable offered for
inspection.
3. APPARATUS
3.1 The apparatus shall be as follows:
3.1.1 Spark tester.
3.1.1.1 A transformer of sufficient capacity to maintain the test voltage specified in the detail specification
under all normal conditions of leakage current.
3.1.1.1.1 The core of the transformer and one end of the secondary winding shall be connected to
ground.
3.1.1.2 A voltmeter shall be so located in the circuit that it will indicate at all times the actual test voltage
applied.
3.1.1.3 The spark tester shall not be simultaneously connected to more than one electrode described in
3.1.2
3.1.2 Electrode.
3.1.2.1 An electrode which makes direct mechanical contact with the surface of the insulation of the wire
or cable undergoing test. A pipe, coiled spring, or the like shall not be acceptable.
3.1.2.2 If the link or bead-chain type of electrode is used, the bottom of the metal electrode enclosure
shall be V-shaped. The chains shall have a length appreciably greater than the depth of the enclosure.
The width of the trough shall be approximately 1 ½ inches greater than the diameter of the largest wire or
cable to be tested.
178
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business