Electrical Testing; Electrical Safety Checks - Class I; Earth Continuity Tests - Getinge Arjohuntleigh NIMBUS II Service Manual

Nimbus/DFS Service Manual
8

Electrical Testing

To test and calibrate the pump unit correctly, the following equipment is required:
Insulation resistance tester (Megger) 500 Vdc
Portable appliance tester
Multimeter/Continuity tester
Dielectric strength tester (Flash tester) 3.0 kVac with current limit

Electrical Safety Checks - Class I

There are several electrical safety checks that must be carried out after breakdown repairs and servicing.
Where alternatives are given, the test will depend upon the available equipment. The tests are as
follows:
•

Earth Continuity Tests

• Insulation Resistance Test (Megger Test) or
• Dielectric Strength (Flash Test)
Earth Continuity Tests
This test is for checking the earth continuity and the earth connection to the metal parts of the appliance,
which may become live because of insulation breakdown (i.e. Those parts which should be earthed).
A voltage is established between the earth pin of the appliance's mains/power supply plug and the metal
parts.
Specification: A (nominal) 25 A current is passed for 10 seconds between the earth pin of the power
plug, and each of the insulated metal parts designated for the product. The impedance should NOT
exceed 0.2Ω
This above test can be conducted with a Portable Appliance Tester.
Alternatively, a Multimeter/Continuity Tester can be utilised, but the impedance is tested using a much
lower current.
Insulation Resistance Tests
This test checks the integrity of the appliance's insulation.
For all appliances, this test is applied between the Live and Neutral wires (connected together), and
earth. In addition, this test is also applied to the Live and Neutral wires (connected together), and the
appliance's enclosure.
Specification: 500 Vdc is applied to the insulation and the measured resistance must be greater than
2 MΩ
This test can be conducted using a Portable Appliance Tester.
Dielectric Strength Test (Flash Test)
This test shows the response of the insulation to high ac-voltage stress, indicates the effects of
capacitive current, and gives an early warning of insulation problems which may develop in the
appliance.
Note: The voltage levels used for this test, may stress and weaken the insulation. This test, is
therefore not recommended as a routine test. It should be only used after a major assembly/
disassembly has been completed.
Issue 2
April 2010
Table 39 - Electrical Test Equipment
Equipment
SER0001
Testing
Chap 6
Page 13