PRODUCT SAFETY SOLUTIONS
© 2017 Educated Design & Development, Inc. All rights reserved. Rev C
Page 13 of 19
OPERATING INSTRUCTIONS: (Continued)
Surface to Surface Leakage Measurement Procedure
1. Isolate the product under test from ground. This can be accomplished by placing the product on a rubber
pad or other suitable insulator. This may also include disconnecting any accessory cables connected to the
product under test
2 Secure the work area so that you or another person cannot accidentally come into contact with the
product during the test. Since the product ground is disconnected while the Ground switch is toggled
OPEN, the product under test poses a potential shock hazard.
3. Set the controls on the LT-952HC as follows:
Voltage selector
115
Power
OFF
Neutral
CLOSED
Line
FORWARD
Meter Connection
SURFACE TO SURFACE
Range
200mA
4. Set the Power switch of the LT-952HC to ON.
5. Connect the product under test to the front panel receptacle. Make sure that the product under test’s
power switch is ON.
6. Connect the test leads from the front panel banana jacks on the LT-952HC to the two surfaces to be
tested on the product.
7. Within a few seconds, the display on the LT-952HC should settle to the final leakage current value. If the
displayed result is less than 20mA operate the Range switch to the 2mA position.
8. IEC60950 specifies that the measurement taken in step 7 be repeated for each position of the products
power switch and with all combinations of the Neutral and Line switches on the LT-952HC. Be sure to
release the Ground switch before changing any of the test conditions (Line or Neutral switches) or before
contacting the device under test. Failure to do this will result in blown meter fuses on the LT-952HC.
Field Testing Grounded Products
(Products that cannot be isolated from earth ground)
These instructions will indicate how to measure leakage current when the device under test (D.U.T.) cannot
be isolated from ground. This may be the case when conducting tests in the field since the D.U.T. may be
reliably connected to ground through the building structure (i.e. mounted to a grounded pad, or connected to
grounded water pipes, etc.).
Please read the section “Understanding Leakage Current” before proceeding. You will note that in order to
measure the entire leakage current of a product, the product must be completely isolated from ground.
However, in a field-testing situation, you may only be concerned with the leakage current through the