Order of Inspection
From your initial AS/NZS 3760 training, you will be aware that we carry out tests in a specific order, for our own safety. For the AS/NZS 3551 this best practice hasn’t changed, in fact according to Appendix B3, it suggests the order that we carry out testing. The following order of inspection is taken directly from AS/NZS3551. However, you may have noticed that The following tests and inspections must always be done in this order:
| 1. Visual Mechnical Inspection |
- Ensure equipment is unplugged from mains supply.
- Start inspection from plug end and work back to the machine (this also ensures that there is no risk of having the appliance still plugged in).
- Decide if the appliance is Class I or Class II.
Always start your visual inspection at the plug end for Class I earthed equipment.
Ensure plug has 3 pins.
| 2. Earth Bond Continuity Test |
- Only done on Class I appliances.
- ALWAYS THE FIRST TEST to be carried out using the PAT (Portable Appliance Tester)
| 3. 250 Volt/500 Volt Insulation Resistance Test |
This test can be carried out on Class I and Class II medical appliances.
| 4. Leakage Test |
This test can be carried out on both Class I and Class II appliances.
| 5. Leakage Test – Neutral Open (3551) |
This test can be carried out on both Class I and Class II appliances.
| 6. Touch Leakage Test (3551) |
In accordance with AS/NZS3551 B 10.1 this test is only required for Class I appliance. A representative sample of exposed metal parts shall (must be) be tested.
| 7. Touch Leakage Test – Neutral Open, Earth Open (3551) |
| 8. Functional Test (3551) |
Note:
For a Class I appliance the order of inspection testing is:
Visual – if a ‘pass’ proceed to
Earth Bond Test – if this is a ‘pass’ then proceed to
Leakage Test
Leakage Test – Neutral Open
Touch Leakage Test
Touch Leakage Test – Neutral Open/ Earth Open
Functional Test
For a Class II appliance the order of inspection testing is:
Visual – if a ‘pass’ proceed to
250V/500V Insulation Resistance Test
Leakage Test
Leakage Test – Neutral Open
Functional Test
We should also mention that while the Standard AS/NZS3551 says this order of inspection could be carried out you may have noticed that the following tests and inspections are carried out in a different order. For example, when using the Metrel AlphaPAT or the Metro iPAT. This is due to the fact that both testers, while they can perform medical testing, were not designed for the sole purpose of medical testing. It’s important to note that regardless of what order the tester performs the above electrical tests, you must always start with a visual inspection.
(Note: the order of testing sequence may change/could be changed depending on the PAT you are using. You will see differences in the iPAT and Alpha PAT for the test sequences).
Again…
ALWAYS START WITH A VISUAL INSPECTION OF THE APPLIANCE!