Automated Test Equipment for Data Center Air Conditioners

A Custom-built fully automated, LabVIEW-powered PC-based test system for Data Center Air Conditioner testing.

The SCR Make PC-Based Test Panel for Data Center Air Conditioner Testing is an integrated, software-driven solution engineered to perform comprehensive validation of air conditioning units.

This testing equipment is designed to automate and streamline the complete performance and safety validation of datacenter AC units with precision and adaptability in mind, this test bench employs LabVIEW-based software and a Siemens PLC module to automate sequential testing workflows.

Our Journey

Since 1975, SCR Elektroniks has been designing and manufacturing specialized electrical test equipment for industries that demand precision and reliability. When ‘Vertiv Energy’ approached us with their challenge of testing precision air conditioning units for data centres, we knew this project would push the boundaries of what’s possible in automated testing.

The result!!!! a fully automated, LabVIEW-powered PC-based test system that revolutionized their quality assurance process

The Challenge We Solved

Data center air conditioners aren’t your typical HVAC units. They operate 24/7 in mission-critical environments where even a few minutes of downtime can cost thousands of dollars. Vertiv needed a way to thoroughly test these units without the inconsistencies and time delays of manual testing.

Their requirements were demanding:

Complete electrical safety verification to international standards
Functional testing under real-world conditions
Consistent, repeatable results with full documentation
Faster testing without compromising thoroughness
Detailed certification for every unit tested

Manual testing was taking over 2 hours per unit, with significant variations between operators. They needed something better.

This SCR Make high-performance test panel is designed considering three core principles: Modularity , Safety without comprimise & Real World Reliability.

The Heart of the System: Our LabVIEW Software

After decades of building test equipment, we’ve learned that great hardware means nothing without equally great software. Our LabVIEW-based control system is the result of years of refinement and real-world feedback. The operator sees everything at a glance – system status, test progress, and real-time measurements. We designed the interface based on feedback from actual production operators, not what looks good in a dem

Full PC-Based Operation:
• No manual override; test sequences executed via LabVIEW
• Customizable test flow by AC model number or test type
• Auto-sequencing with failure-based termination logic
Multi-Level Access Control: Ensures the right people have the right access. Role-based permissions enhance security and audit compliance.
Real-Time Data Visualization: Live performance metrics and color-coded status indicator system improves oversight.
Data Integrity: Sequential documentation with timestamps for every test cycle supports compliance documentation.
Emergency Stop Integration: Accessible across all screens.
Modularity: Every component can be upgraded or modified without rebuilding the entire system.

Controlled Interface: PC-based operation via LabVIEW and Siemens PLC
Input Voltage : 3Phase, 415V ±10%, 50Hz
Output Supply : Single Phase, 240V, 35A AC
Test Supported :
- Earth Bond Test (6–10A; Resistance ≤ 0.1Ω)
- HV Test (0–6kV AC/DC) Trip current settable: 1–40mA AC / 1– 10mA DC)
- Insulation Resistance Test (500V DC; pass/fail logic)
- Earth Leakage Test (Limit: 1–15mA, cumulative monitoring)
- Run Tests (Fan RPM, dual pressure transducers, valve control)
Hardware Support:
- PC with Windows 11 & MS Office
- Siemens PLC + TC Module
- Yokogawa Clamp-On CTs (6x), Pressure Transducers (6x)
- HV Tester (GPT-9803), Barcode Scanner, Printer, UPS for PC
- Modbus converter (as per design), Bluetooth module
- Powder-coated MS trolley panel with built-in PC mount

Control System

User Management:
We've seen too many systems where security is an afterthought. Our multi-level access control ensures the right people have the right access:
-Operators can run tests and view results
-Supervisors can modify test parameters and access reports
-Administrators control user accounts and system settings
-Service technicians have calibration and maintenance access
All actions are recorded with precise timestamps and associated user IDs.
Test Recipe Management :
Different air conditioner models need different test parameters. Our recipe system makes this simple:
-Each model gets its own validated test recipe with pre-set limits and sequences.
-Operators just select the model - the system handles the rest.
- No more manual parameter entry, no more typographical error. We include version control too. Whenever test requirements are modified, the system provides a clear audit trail detailing what changed and when
Siemens PLC Integration:
A Siemens S7-1200 PLC handles all real-time control functions. If the PC fails, the PLC can safely shut down the test and protect the equipment.
The PLC manages:
- 32 digital inputs for status monitoring
-16 digital outputs for control functions
-8 analog inputs for sensor data
-4 analog outputs for control signals
-High-speed counters for RPM measurement
Communication Network :
Everything connects via Modbus - a proven industrial protocol that's been reliable for decades. This makes it easy to add new instruments or replace existing ones without major system changes.

Testing Modules

Test Name	Parameters & Description
Earth Bond Test	6–10A AC current; resistance limit ≤ 0.1Ω; test result shown on PC
HV Test	GW-Instek GPT-9803 source; 0–6kV AC/DC with ramp-up/down; trip current (AC: 1–40mA / DC: 1–10mA)
Insulation Resistance	500V DC in OFF condition; If the resistance is less than the set value ‘Fail’ indications will be given and test will be terminated.
Earth Leakage Test	Conducted during Run test; current range: 1–15mA; If the current is more than the set value. Fail Indication will be given & Test will be terminated.
Performance (RUN) Tests	Sequential testing with RPM sensing, dual pressure transducers, valve actuation. Operational Performance Tests Earth Leakage Current: Live monitoring under load conditions Compressor Performance: Startup, steady-state, and cycle evaluation Fan System Checks: RPM, airflow, noise, and vibration diagnostics Refrigeration Analysis: Pressure decay, charge verification, temperature mapping Control System Validation: Alarm accuracy, interface checks, communication testing

Vertiv’s comment

“Thesystem has completely transformed our testing process. What used to take 2+hours now takes 30 minutes, and the results are far more consistent than weever achieved manually.”

The numbers speak for themselves:

75% reduction in test time
99.5% test repeatability (vs. significant variation with manual testing)
Zero safety incidents since installation
100% documentation compliance for audits

Overall efficiency improvement: 300%
Customer complaints: Reduced by 60%
Labor cost per test: Reduced by 70%
Rework costs: Reduced by 50%
Warranty claims: Reduced by 40%
ROI achieved in 18 months

After 18 months of operation at Vertiv, our metrics based on Productivity, Quality & Costing

Metric	Before	After
Test Time per Unit	2 hours	30 minutes
Setup Time	15 minutes	2 minutes
Report Generation	1 Hour min	Instant
Documentation	80% complete	100% complete
First-Pass Yield	85%	96%
Safety Incidents	Several reported	Zero
Test Repeatability	±2%	±0.1%