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factory acceptance test

What Is SCADA System Factory Acceptance Testing (FAT) and Why Is It Important?

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The purpose of Factory Acceptance Testing (FAT) is to demonstrate the hardware quality, system configuration, and specification compliance of the SCADA system prior to shipping to the solar PV project site.


In short, it ensures that the SCADA system works the way it's supposed to and meets customer requirements.


During the FAT, tests are performed to verify the correct implementation of the design of the entire system, including the HMI, associated network infrastructure, controllers, and all associated applications.


1. When does the FAT occur in the project lifecycle for SCADA configuration and deployment?

The FAT takes place before the SCADA rack ships to the solar PV project site. It is easier for the SCADA integrator to make adjustments to the system while it is still in-house rather than out in the field. Later, Site Acceptance Testing (SAT) is performed to test the system once it has been installed in the field.


For most projects, the SCADA rack will be housed in the plant substation. At Nor-Cal, we schedule the FAT 30 days prior to the completion of the substation building construction. This provides time to work on any punch list items arising from the FAT while allowing 15 days for shipping.


2. Why is it necessary for customers to witness the FAT?

By witnessing the FAT, the customer can make sure the system is up to their standards and get a look and feel for it prior to implementation at the project site. The FAT also serves a dual purpose providing a quick training session on the function and benefits of the system.


It is up to the customer if they want to review the FAT in person or virtually. The reviewer can be the owner, a consultant hired by the owner, and/or a representative for the EPC building the solar PV site.


3. What does a SCADA system FAT cover?

The SCADA integrator should have a documented procedure for the FAT that is specific to the customer. At Nor-Cal, our typical FAT includes the following sequence of activities:

  • Bill of Material (BOM) verification (ensuring everything that was contracted for is included in the system)
  • Hardware inspection/verifications (ensuring the rack is built properly and all hardware is functioning as it should)
  • Software inspection/verifications
  • Communication and connectivity verifications (ensuring all cabling is connected and labeled properly)
  • HMI functionality verifications (verifying that the HMI screens meet customer requirements)
  • Functional logic verifications (alarms and controls testing)
  • General system functionality verifications

The FAT tests each of the system components included in the project scope. These typically include:

There are other items that aren't tested during the FAT because they either aren't part of the SCADA provider's scope of supply, and/or they are installed onsite. These items are tested and proved later as part of the SAT. They typically include:

  • Customer historian
  • ISP / MPLS
  • Substation RTAC
  • Trackers
  • Inverters
  • MET station and/or soiling station

Logical Testing & Real-Time Data Simulation

A major portion of the FAT is logical testing. This ensures that:

  • Proper alarms are generated based on any type of physical device failure
  • Alarms are properly depicted on the HMI screens
  • The PLC can fulfill required plant control functions

The PLC's (PPC) job is to control plant output to meet specified ISO/utility standards. Since the FAT is done prior to installing the SCADA system onsite, the real-time field device data needed to test the control functionality isn't available. The SCADA integrator must simulate that real-time field data using software.


At Nor-Cal, we have RTDS real-time simulator software that allows us to simulate the exact devices that will be out in the field. The control logic "thinks" it is connected to the device, but it's actually connected to the simulator. This allows us to complete up to 96% of the controls testing prior to shipping the SCADA rack to the site, as opposed to about 90% without the simulator.


The final part of the logical testing includes testing megawatt control, behavior control, frequency control, power factor control, and reactive power control.


4. How do EPCs facilitate FAT? What is their role in the process?

In cases where the SCADA rack is built somewhere else other than the SCADA integrator's facility, the EPC contractor will conduct the FAT and make sure that the integrator has access to the equipment beforehand for programming. The exact steps of the FAT will vary based on the EPC requirements, but in general it should be similar to what is described above.


It is in the EPC contractor's best interest to perform a thorough FAT. As mentioned earlier, it is much easier to make adjustments to the system at the facility than it is in the field. This makes commissioning the system much faster and easier for everyone.


5. Do asset owners have a role in the FAT?

In our experience, site owners are always involved in the FAT. With asset owners, it depends on their role and when they are brought into the project. If the owner brings the asset owner who will manage the plant into the project ahead of time, they will typically want to be involved in the FAT. After all, they will be responsible for taking care of the plant for the site's lifetime which is typically 25 years or more. At Nor-Cal, we have seen asset owner involvement in the FAT grow increasingly common.


Nor-Cal can set you up for success with your solar PV SCADA system.

With over 14GW worth of successfully commissioned solar PV projects to date, we can provide a SCADA system that will meet your requirements and deliver cost efficiency and performance over the long term. Since our SCADA systems are based on open architecture hardware and software, you're not locked into one OEM, and you avoid proprietary data access fees and restrictive service contracts.


Schedule a call with us today.


Abhishek Dabholkar

Written by Abhishek Dabholkar