Dubuque Municipal Building - 203 kW flat roof pv system

At SolarDock, we want to be the safest and strongest ballasted racking system on the market, and demonstrate this through our commitment to thorough product testing and evaluation.

In 2003, SolarDock was one of the first ballasted racking systems to be listed by UL, and in 2014 was one of the first low-slope systems to be fully tested under UL 2703. Our ballast calculations were developed by a PE using the results from 150 mph wind tunnel tests and CFD analysis.

SolarDock well surpasses the minimum mechanical load requirements in the proposed UL 2703 standard for solar racking and mounting systems. Tested for mechanical strength by TUV Rheinland, SolarDock successfully withstood the following loads:

  • Downward: 113 lbs/sf (5400 Pa)
  • Upward: 50 lbs/sf (2400 Pa)

What is Mechanical Load Testing?

During testing, weight is attached to the solar racking system in a way that simulates the kinds of forces it will experience during its lifetime. Downward forces are simulated by placing weight on top of the test system. Upward forces are simulated by hanging the system upside down and attaching weight to the bottom.

The tests are typically conducted for 30 minutes, and afterward the racking system is evaluated to see if it remained mechanically sound. The end result is a Mechanical Load Rating that is used during the design phase of the solar project.

Why care about Mechanical Load Ratings?

Solar racking and mounting systems are supposed to hold the solar panels in place, protecting not only your investment in the equipment, but also the property and people around it. Mechanical Load Ratings tell you how much force the racking system can withstand and still be sound.

High winds and large snow storms can place a lot of stress on the system. You’ll want to be sure the solar racking system you choose can withstand that stress over the lifetime of the system.

In tests conducted by TUV Rheinland PTL, SolarDock’s unique pan-based design successfully resisted the spread of fire on a rooftop, earning a Class A Fire Rating for the Fire Resistance Tests required by the UL 1703 & 2703 standards.

What is Fire Resistance Testing?

Fire Resistance Tests are designed to determine what effect the presence of a solar system will have on a roof in the event of a fire. There are two tests required by UL 1703 and the proposed UL 2703 standards, Spread of Flame and Burning Brand. The tests are conducted on a Class A roof deck, with solar modules fully installed.

SolarDock’s first round of fire tests were conducted with Class C PV panels, and earned a Class A rating for the PV system.

Spread of Flame Tests

In this test, the SolarDock test system is placed on the test deck, and flame is applied for 10 minutes. The distance the flame spread during that time is compared to the average spread of flame for the test roof deck without the solar system on it. To earn a Class A rating, the spread of flame needs to be less than 6 feet. Because of the tilt of the system, tests were conducted in three directions, North, South, and East.

⇒ Results: the SolarDock system not only earned a Class A rating, but also reduced the spread of flame by more than 60%.

Burning Brand Tests

In these tests, a piece of metal is super heated and placed on and underneath the test system. The brand is allowed to burn for 10 minutes, after which the impact of the fire on the test roof deck is examined. To earn a Class A rating, an A class brand must be used, no flaming/glowing brands can fall on the test deck, and the test deck cannot experience sustained flaming.

⇒ Results: the pan based, fully enclosed design of the SolarDock system prevented brands from falling onto or burning the test roof deck, earning a Class A rating.

Why care about Fire Ratings?

With several high profile fires in 2014 & 2015, there has been increasing scrutiny of the solar industry?s role in fire safety. California Fire Code, 2012 International Building Code, and International Fire Code already require PV systems to hold a fire rating, and many buildings will require the PV system to be rated Class A in order to meet code.

In addition, companies involved in financing and insuring systems are becoming increasingly concerned about the risk they are taking on when they back large PV systems. Systems that are not fire rated (or hold a low rating) will likely have higher financing rates and larger insurance premiums.

What is the UL 2703 standard?

UL 2703 is an ANSI approved standard that establishes the minimum material, mechanical, electrical, and fire safety requirements for mounting systems and devices used with flat-plate photovoltaic modules.

UL 2703 tests include: Bonding Path Resistance Test • Terminal Torque Test • Fire Performance Test • Accelerated Aging Test • Temperature Cycling Test • Humidity Test • Corrosive Atmosphere Tests • Metallic Coating Thickness Test • Mechanical Loading Test • Bonding Conductor Test • Bonding Strap Pull Test

UL 2703 also covers: Materials used • Installation manual requirements • Labeling specifications

Why is the UL 2703 standard important?

Until the adoption of the UL 2703 standard in January 2015, there was no standardized way to compare the safety claims of mounting systems on the market.

Claiming a product “passed rigorous testing” could mean anything from “we’ve had our in-house engineer look at it” to “we’ve been evaluated and certified by a Nationally Recognized Test Lab”.

Now with UL 2703, customers can be assured that products holding this certification have been tested by a Nationally Recognized Test Lab to industry agreed minimum standards.

What is the difference between UL 2703 tested and UL 2703 certified/listed?

The UL 2703 tests demonstrate the safety characteristics of the product; a full UL 2703 certification/listing involves a comprehensive review of the installation manual, product label, and manufacturing processes.

Completing the full UL 2703 certification demonstrates a deep commitment to safety by the company holding the certificate.

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