combined thermal shock g-force halt test on hiq solar...

Test Report Number 2755

Reliant Labs, Inc. 925 Thompson Place • Sunnyvale, California • 94085

Phone 408.737.7500 • Fax 408.850.1852 • reliantlabs.com

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Combined Thermal Shock G-Force HALT Test on HiQ Solar

TS480-8k TrueString Inverter

Prepared for: HiQ Solar, Inc. 2030 Duane Avenue, Suite 101 Santa Clara, CA 95054 Phone (408) 970-9580 www.hiqsolar.com




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Combined Thermal Shock G-Force HALT Test

Document Number 2755

Test Dates: 02/12/2015

TrueString 480V Inverter

Model Number: TS480-8K

Testing Performed for:

HiQ Solar, Inc. Phone: (408) 970-9580 2030 Duane Avenue, Suite 101 Web: www.hiqsolar.com Santa Clara, CA 95054

Testing Performed by:

Reliant Labs, Inc. Phone: (408) 737 - 7500 925 Thompson Place Fax: (408) 850 - 1852 Sunnyvale, CA 94085 Email: [email protected]

Reference Documents Document Revision Number Date Issued

- - - -

www.hiqsolar.com




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Table of Contents:

1. Objective............................................................................................................................ 4

2. Scope ................................................................................................................................ 4

3. Acronyms and Definitions .................................................................................................. 4

4. Executive Summary ........................................................................................................... 4

5. Combined Environment Profile .......................................................................................... 5

6. Test Results - Level 1 ........................................................................................................ 6

7. Products Tested................................................................................................................. 8

8. Temperature Test Setup .................................................................................................... 8

9. Vibration Test Setup .......................................................................................................... 8

10. Test Equipment and Calibration Records ........................................................................... 9

10.1. Customer Test Equipment .................................................................................... 9

10.2. Reliant Labs Calibration Records .......................................................................... 9

11. Functional Test Description ..............................................................................................10

Appendix A – Photographs .......................................................................................................11

Appendix B – HALT Six Degrees of Freedom Random Vibration ..............................................15




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1. Objective Combined Thermal Shock G-Force HALT Test is performed to uncover latent defects in product design, component selection, and/or manufacturing that would not otherwise be found through conventional qualification methods. The process subjects the test sample to a combination of temperature and vibration to precipitate inherent defects.

2. Scope Run the Level 1 combined environment profile on a functional HiQ Solar TrueString 480V Inverter (HiQ Solar TS480-8k).

3. Acronyms and Definitions

H.A.L.T. – Highly accelerated life test

UUT – Unit under test

Grms – Gravity Root Means Squared.

4. Executive Summary

The HiQ Solar TS480-8k sample remained operational and passed during the Level 1 combined temperature and vibration profile.




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5. Combined Environment Profile

Level 1 - Combined Thermal Shock G-Force HALT Profile:

Lower Set Point: -40°C

Upper Set Point: +65°C

Ramp Rate: 10°C per minute

Dwell Time at each extreme: 10 minutes

Cycle Length – 41 minutes

Total Cycles: 5

Test Duration: 3.4 hours

U.U.T.s – Functional

Samples per Test: 1 unit

Figure 1 Combined Environment Test Profile - Level 1

-50

-40

-30

-20

-10

0

10

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30

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50

60

70

80

12

:00

AM

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:08

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:16

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:25

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:41

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:58

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1:0

6 A

M

1:1

5 A

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8 A

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8 A

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Tem

pera

ture

(C

) / V

ibra

tio

n (G

rms)

Time

Combined Temperature and Vibration Profile - Level 1

Temp Setpoint Vibe Setpoint




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6. Test Results - Level 1

The UUT was exposed to 5 rapid temperature cycles from -40°C to +65°C combined with vibration. The vibration level was set to a constant 25 Grms. The dwell time at each

temperature extreme was 10 minutes and the thermal transition rate was set to 10C per minute. The UUT was monitored for functionality throughout the combined environment process.

Table 1: Combined Environment Results

Cycle

Chamber Set point

(C)

Chamber Set point (Grms)

Pass/Fail

Comments

0 +20 0 Pass Test Date: 02/12/2015 Test Sample: SN_2722

1 Transition 25 Pass

1 -40 25 Pass


1 +65 25 Pass

1/2 Transition 25 Pass

2 -40 25 Pass


2 +65 25 Pass


3 -40 25 Pass


3 +65 25 Pass


4 -40 25 Pass


4 +65 25 Pass


5 -40 25 Pass


5 +65 25 Pass


+20 0 Pass




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Figure 2 Combined Environment Chart

-50

-40

-30

-20

-10

0

10

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30

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3 A

M

9:5

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1:0

3 P

M

1:1

2 P

M

Tem

pera

ture

(C

) / V

ibra

tio

n (G

rms)

Time

Combined Temperature and Vibration Chamber Data - Level 1

Temp Setpoint Temp Control Temp Air Vibe Setpoint Vibe Table (input)




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7. Products Tested

Table 2: Product Identification

Description Model Number Revision Serial Number HiQ Solar TrueString 480V String Inverter HiQ TS480-8k - 2722

8. Temperature Test Setup

Airflow from the chamber was directed onto the UUT using 4” aluminum ducting. This allowed for better temperature stabilization during the thermal cycling process. Pictures illustrating the temperature test setup are located in Appendix A.

9. Vibration Test Setup

The UUT was mounted to the vibration table using two 16”L x 2”W x 1”H sections of aluminum channel. The aluminum channel were bolted to the vibration table at four locations using 3/8” - 16 threaded steel rod. Pictures illustrating the fixture setup are located in Appendix A.




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10. Test Equipment and Calibration Records

10.1. Customer Test Equipment

Functional test equipment provided by the customer and used to conduct the H.A.L.T. testing is detailed below. The model number and serial number have been documented to aid in the reproducibility and repeatability of test results.

Table 3: Customer Test Equipment

Description Manufacturer Model Number Quantity AC Transformer Temco TT1292 1

DC Power Supply Main Wall S-350-36 16

Gateway HiQ Solar GTWY1-Rev A 1

10.2. Reliant Labs Calibration Records

Equipment used to conduct the testing is detailed below. All test equipment that requires periodic calibration was in current calibration at time of test. The calibration certifications are traceable to the National Institute of Standards and Technology (NIST).

Table 4: Reliant Labs Calibration Records – Lab 5

Description Manufacturer Model Number Serial

Number Calibration

Due HALT Chamber Qualmark Typhoon 3.0 30T11090903 08/06/2015

Thermocouples Omega TT-T-30-SLE ROHS NA NA

Accelerometer Control PCB 300-0221 P14187 07/23/2015




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11. Functional Test Description

During testing the UUT was continually monitored for functionality.

Test equipment used to monitor the UUT was set up on a bench outside the H.A.L.T. chamber. Cables, wires, and power cords were fed through the chamber access port. Before running the H.A.L.T., the following modifications were made to the UUT:

Functional test cables were modified to reach outside the chamber.

During the test process, any abnormalities are considered possible failure modes until they can be determined otherwise. To establish clear failure characterization the list below details acceptable specifications and/or unit functionality.

Monitored LED status and current draw throughout the test.

The following was monitored on the communications Gateway:

System health.

Power output.




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Appendix A – Photographs

Figure A.1. Temperature & Vibration Test Setup




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Figure A.2. Chamber Control Thermocouple Location




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Figure A.3. Test Equipment Setup




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Figure A.4. Chamber Lab Setup




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Appendix B – HALT Six Degrees of Freedom Random Vibration

HALT vibration systems produce energy in all six axis simultaneously (x, y, z, pitch, roll and yaw). The frequency output is broadband from 2 Hz to 5 KHz.

Figure 3 Tri Axial Accelerometer Figure 4 – X, Y, Z, Pitch, Roll & Yaw

Pneumatic or repetitive shock 6DOF vibration HALT chambers produce a continuously varying pseudo-random broad spectrum vibration. The vibration is controlled from a single accelerometer mounted at the center underneath the vibration table. The root mean square (RMS) value of this signal can be calculated by squaring the magnitude of the signal at every frequency, finding the average (mean) value of the squared magnitude, and then taking the square root of the average value. The resulting number is the Grms.

X

Y

Z

X

Y




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Figure B.1 Location of Accelerometers 2-4

Accelerometer 2 Z-axis

Accelerometer 3 X-axis

Accelerometer 4 Y-axis




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Figure B.2 Location of Accelerometer 5-6

Accelerometer 5 Z-axis

Accelerometer 6 X-axis




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PSD Vibration Plot - 25 Grms 2 Hz – 2.5 kHz

Spectrum Analyzer Channel Assignment Channel Axis Location or Description

1 Z Mounted underneath the vibration table at center.

2 Z Front - Mounted on the Z axis

3 X Front - Mounted on the X axis

4 Y Front - Mounted on the Y axis

5 Z Back - Mounted on the Z axis

6 Z Back - Mounted on the X axis

Note: The X-axis runs through the chamber doors, the Y-axis runs from the access portal to air plenum, and the Z-axis is vertical to the vibration table.

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

0 500 1000 1500 2000 2500

Grm

s2

/Hz

Frequency (Hz)

Power Spectral Density

Channel 1 (16.9 Grms) Channel 2 (11.07 Grms) Channel 3 (6.54 Grms)





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PSD Vibration Plot - 25 Grms 2 Hz – 10 kHz

Spectrum Analyzer Channel Assignment Channel Axis Location or Description

1 Z Mounted underneath the vibration table at center.

2 Z Front - Mounted on the Z axis

3 X Front - Mounted on the X axis

4 Y Front - Mounted on the Y axis

5 Z Back - Mounted on the Z axis

6 Z Back - Mounted on the X axis

Note: The X-axis runs through the chamber doors, the Y-axis runs from the access portal to air plenum, and the Z-axis is vertical to the vibration table.

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Grm

s2

/Hz

Frequency (Hz)

Power Spectral Density

