Simpson 228 - Shock Hazard Measurement; Polarity Reversal

15
7.5 Shock Hazard Measurement
1. Turn Function Select Switch to 10MIU SHOCK HAZARD (see Figure 7 below).
Figure 7
2. Use Positive Test Lead to probe all accessible conductive surfaces and check
for excessive current leakage. Read the 0-10 MIU scale. If measured current is
less than 1/3 of full scale, increase meter sensitivity by turning the Function
Select switch clockwise until pointer is in upper 2/3 of the dial.
Note: ANSI C101.1 limits current leakage to 0.5 MIU RMS for most appliances, but
exceptions are allowed for unique situations. Refer to the equipment manufacturer or
applicable safety standard for more details. Proceed only when shock hazard measure-
ments are within acceptable limits.
7.6 Polarity Reversal
1. Use SW2 switch (see figure 4, page 13) to reverse the hot and neutral. Do not
close SW1 to activate the unit under test. Repeat Voltage, Burn Hazard, and
Shock Hazard tests. After completing tests, return SW2 to original position.
2. Close SW1 and turn equipment on.
3. Use Positive Test Lead to probe all accessible conductive surfaces in order to
determine if excessive voltage is present. Read the 0-300 volts (bottom) scale.
a. If the voltage measurements appear normal, proceed to step 4.
b. If measured voltage is above expected value, check equipment for short cir-
cuits and make any necessary repairs before continuing. Abnormally high volt-
ages that persist without corresponding short circuits indicate current leakage.
4. Turn Function Select switch to BURN HAZARD (see Figure 6, page 14).
5. Use Positive Test Lead to probe all accessible conductive surfaces and check
for excessive current leakage. Read the 0-100mA RMS scale.
NOTE: Most safety specifications set a limit of 70mA for this measurement. Refer to
the appropriate specification (or equipment manufacturer) for the correct limit. Pro-
ceed only when burn hazard measurements are within acceptable limits.
OUTPUT
REACT.
LET GO
228
3
10
1
.3
ON
BATT.
OFF
+
WARNING
READ MANUAL BEFORE USE
!
+
SHOCK
HAZARD
LEAKAGE CURRENT TESTER
RESPONSE
(MIU)
BURN
HAZARD
(0-100mA)