Waterproof function and the measurement of the standards for power supply

July 22, 2022

Introduction:

      People have common sense that water or liquid should not contact electronic components in order to prevent damage. However, in outdoor applications, the environment is harsher and may have more chances to contact water or any kind of liquid. To let the power modules operate stably in the harsh environment, the way of designing and verifying the waterproof function would be a critical topic. Besides outdoor applications, the waterproof function is also demanded in home healthcare applications. In this article, we will discuss the waterproof standard and the test to verify the product based on the standard.

Waterproof and Dustproof standard: IP (Ingress Protection Code)

      IP (Ingress Protection Rating) is a global standard to define the level of sealing effectiveness of preventing the objects (like sand, dust, rock etc.) and liquid from external environment. There are two numbers coming right after IP which represent the protection levels of solid object and moisture.

The following tables briefly explain the requirement of each level of the number:

First Digit: Solid particle protection

Second Digit: Liquid particle protection

TR36M testing for IP standard

      Taking Cincon TR36M as the example, it was sent to the certificated lab for IP22 testing. The followings are the test equipment and the description of the procedure:

1. Equipment:

2. Environment:

3. Testing standard:

Reference to IEC60529:1989+A1 : 1999+ A2:2013

4. Testing condition(s):

IP2X: Probe the sample slit portion with a test probe of 1mm and the test force of 30N. (Fig. 3- Fig. 5)

IPX2: Drip water flow: 3mm/min

The highest point of the sample and the distance from the drip hole: 200mm.

The sample is inclined in four fixed positions with each test 2.5mins. These four positions are in two mutually perpendicular planes with each inclined 15° from the vertical. (See from Fig. 6 to Fig. 10.)

Test duration: 10 minutes

5. Judging Criteria:

IP2X: The probe can’t puncture any openings into the sample and gap.

IPX2: Allow a small amount of water to enter the inside of the sample, but water is not allowed to accumulate in the charged part.

6. Result:

TR36M passes both IP2X and IPX2.

7. Testing photos:

IP2X: The probe didn’t penetrate the openings or gaps on the case.

Before test	Fig. 2
IP2X- Testing 1	Fig. 3
IP2X- Testing 2	Fig. 4
IP2X- Testing 3	Fig. 5

IPX2: No water accumulates in the charged parts inside sample.

IPX2- Testing setting	Fig. 6
After test-1	Fig. 7
After test-2	Fig. 8
After test-3	Fig. 9
After test-4	Fig. 10

Home healthcare device requirements for water ingress (IEC60601-1-11)

      In the household environment, the waterproof function would be critical due to accidental water spill and moisture ingression. Especially for medical devices, the leakage current is extremely restricted and may possibly influence patient health conditions. The IEC60601-1-11 standard states clearly the waterproof requirement for the home healthcare device. For devices that do not have contact with body, the enclosure must be at least IP21. For devices that have direct contact with body, the enclosure must be at least IP22.

Cincon power supplies with waterproof design

      Cincon offers a series of medical desk-top and wall-mount adapters compliant to the waterproof standards for home healthcare applications such as ventilator, diagnostic and monitoring equipment. By the sealing structure, these series could operate in the household environment and protect both users and the electronic components.

The table below shows the product list suitable for home healthcare applications:

Contact for more support:sales@cincon.com.tw