Leakage Current Test - Pentax EPK-p Service Manual

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 current test Jig ST-5911
Meter-B
0.15uF
Leakage current meter
Leakage Test & its condition
1 Casing Leakage
2
Protective earthing leakage
3
4
Patient applied part leakage
5
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.
Equipotential terminal
GND
Fig-6 Leakage current test
N.C.
N.C.
S.F.C.
N.C.
S.F.C.
Table-3 Leakage Current Criteria
Point-A
EPK-p
Meter-A
0.15uF
Point-A Point-B
Connected Connected
*2
Connected Open
*3
Open Open
Connected Connected
Connected Open
- 11 -
Point-B
AC power
GND
Leakage current meter
GND
*4
AC input
110% VAC 100µA
110% VAC
110% VAC
110% VAC
110% VAC
Standard
*1
500µA
1000µA
100µA
500µA