- 11 -
7.3 Leakage current test
Table-3 shows the limit values of leakage current in the specific test condition.
Check that each measured leakage current value is within the specific value with the following procedures:
1) Set the leakage current meter as shown in Fig-6 (Meter-A: Casing and Protective earthing leakage test
/ Meter-B: Patient applied part leakage test).
Note: 1) Put a capacitor (0.15uF) between the probes of the meter as shown below as a bypass for the leakage
current of a certain frequency which is not harmful for the human body.
2) Equipotential terminal is equal to the chassis ground.
3) ST-5911 is a jig to connect the leakage current meter to the patient circuit ground.
4) We recommend a leakage tester which has a capability of automatically measuring all kinds of leakage
current required for the medical equipment safety.
2) Set the AC power line condition described in Table-3 depending on the test type and connect the AC
cable to the EPK-p.
3) Apply 110% AC voltage, turn on the EPK-p and turn on the lamp and pump in high-mode.
4) Measure the leakage current value indicated on the meter and record it.
5) Turn off the EPK-p and change the polarity of the AC power by reversing the AC plug.
6) Do the item 3) and 4) again. Take the worse value (higher one) as a result of each test.
Leakage Test & its condition
Point-A
Point-B
AC input
*4
Standard
1
Casing Leakage
N.C.
Connected
Connected
110% VAC
100µA
*1
2 N.C.
*2
Connected
Open
110%
VAC
500µA
3
Protective earthing leakage
S.F.C.
*3
Open Open 110%
VAC
1000µA
4 N.C.
Connected
Connected
110%
VAC
100µA
5
Patient applied part leakage
S.F.C. Connected
Open
110%
VAC
500µA
N.C.:
Stands for “Normal Condition”. Status assuming that AC power lines of Live and Neutral and
GND are correctly connected.
S.F.C.:
Stands for “Single Fault Condition”. Status assuming that accidentally either one of the AC
power lines or GND is disconnected.
*1. The regulation value is 500µA, however in logical terms the actual value is more or less zero. If
there is some value, you need to check whether the GND line has been connected correctly or not,
or the quality of the GND line.
*2. The condition without GND line is the Normal Condition at the Protective earthing leakage test.
*3. The condition without both the AC line(either one of AC lines) and GND line is the Single Fault
Condition at the Protective earthing leakage test.
*4. Supply 110% voltage of AC. For example, if the normal voltage is 100Vac, the supply voltage will
become 110Vac. 120Vac > 132Vac, 230Vac > 253Vac. If you can supply only 100% voltage instead
of 110%, convert the measured leakage current into the value at with 110% voltage of AC.
Fig-6 Leakage current test
Table-3 Leakage Current Criteria
AC power
Point-A
Equipotential terminal
Leakage current meter
GND
Meter-B
Leakage current test Jig ST-5911
0.15uF
GND
Leakage current meter
GND
Meter-A
0.15uF
Point-B
EPK-p
