Purchase Specification
for a
Solar Engine Power Supply
for Airfield Lighting
Overview
This specification is for a solarengine power supply for airfield lighting applications, herein referred to as the “solar engine”.
The solar engineshall provideconstant-current power to LED-based signs, windcones, elevated runway guard lights (ERGLs), and other airfield lighting components.
Each solar engineshall consist of or be capable of:
- Monocrystalline solar panel with adjustable angle
- One or two premium VRLA (Valve-Regulated Lead Acid) AGM batteries
- Microprocessor-based control electronics
- Dual configurable LED driver channel outputs
- Dusk-to-Dawn operation or on-demand activation via wireless control
- Onboard LED status indicators
- Onboard pushbutton for group assignment
- USB programming
- Two mounting legs with frangible couplings
1.0 Mechanical Specifications
The solar engineshall be a single enclosure incorporating a hinged solar panel, batteries, control electronics, wireless modules, antenna, LED power supply harnesses and mounts.
The solar engine shall be painted aviation yellow RAL 1006.
The installed weight of asolar engine with one battery shall be approximately 60kg (132 lbs.).
The installed dimensions of an solar engine shall be 759 H x 1089 W x 441 D mm / 29.9 H x 42.9 W x 17.4 D inches (with wireless antenna and panel inclined at maximum tilt angle to produce maximum vertical height).
The solar engine’s mechanical enclosure shall be5052 aluminum and powder-coated for resistance to wear and corrosion with stainless steel hardware throughout.
The solar engine’s interior shall be accessed by undoing two thumbscrews and tilting the hinged solar panel upwards. The solar panel shall be held in place by a gas spring for ease of installation and maintenance.
The solar engine enclosure shall incorporate screened venting to allow air flow through the interior without compromising its resistance to rain and spray or insect ingress.
1.1 Mounting
The solar engine shall be mounted on two legs with frangible couplings and 2.5"-8 NPT (tapered) floor flanges
A tether kit shall be available as an option to anchor the solar engine to the ground.
1.2 Solar enginePower Supply Capabilities
The solar engine shall be capable of providing programmable drive current on each of the two independent output channels.
Each of the two channels shall be capable of providing constant current output between 0.3 and 1.4 amps with a supportable output voltage between 18 and 38 volts DC and with a duty cycle from 5% to 100%.
The solar engineshall be able to operate from dusk until dawn in “autonomous” mode whereby the output channels provide current to the LED loads during the night.
If enabled for wireless control, the solar engine shall also be capable of responding to on-demand wireless control at any time of day or night.
When operated wirelessly, the solar engine shall be capable of multiple LED output currents (corresponding with multiple load intensities).
The solar engineshall use solar panel output as the means to determine whether it is day or night.
2.0 Subsystem Specifications
2.1 Solar Panel
The solar engine shall use a premium monocrystalline 95-watt solar panel rated for 17.5 volts and 5.45 amps at the maximum power point. The solar panel shall conform to Type 61215 IEC and shall have a minimum output of 90% at 10 years of service life.
To adjust the solar panel angle, the complete solar engine is rotated. The solar panel can be set for 15, 35 or 55 degrees above horizontal, depending on the latitude of the solar engine’s location.
The solar engine shall employ MPPT (Maximum Power Point Tracking) to derive the maximum amount of available power from the solar panel.
2.2 Battery
The solar engine shall use as default one sealed VRLA (lead-acid) 12 volt Group 27 AGMbattery, with an option for a second identical battery.
An individual battery shall have a capacity of 105Ah at C/100 discharge rate.
The positive battery cables shall be fused for 10 amps maximum current.
The battery shall be secured in place to prevent movement.
On-board battery status shall be available to users via status LEDs.
The solar engine’s operation and depth of battery cycling while in autonomous mode shall be designed for a five-year battery life.
The solar engine shall be configured to provide a minimum of seven days of autonomy to ensure long battery life.
The solar engine shall apply temperature-compensated battery charging based on a temperature sensor inside the enclosure.
The batteries shall be replaceable and recyclable.
The manufacturer shall offer complete battery replacement kits and kits containing the required tools to perform the replacement.
2.3 Electronics
The solar engine’s control system shall offer:
- Automatic light control dynamically reduces output currents in response to unusually low amounts of sunlight to ensure continued autonomous operation
- Direct and float battery charging modes when charging via the solar panels
- Low-voltage disconnect (LVD) to prevent over-discharge of the battery system
- Maximum Power Point Tracking (MPPT) for matching the optimal solar panel and battery charge operating points
- A constant current drive to the output LEDs for consistent brightness and chromaticity during changing battery voltage
- Integrated circuit protection
The solar engineshall maintain an internal datalog that can be retrieved via a USB data connection.
The solar engineshall be capable of receiving firmware upgrades.
2.4 Wireless
The solar engine shall use the 900 MHz ISM band with FHSS (Frequency Hopping Spread Spectrum) and 256-bit AES encryption. The solar engine shall be capable of responding to wireless control up to 4km from the control device.
The solar engine will operate only in “receive” mode.
The external removable antenna shall be omnidirectional, 1/2 wave dipole, and 50-ohms impedance.
2.5 Electrical
The solar engine shall provide current to external LED loads using a 6-conductor weatherproof cable that is 6.7m / 22 feet in length. The load cable shall be able to exit the solar engine either via a side conduit or down through a mounting leg.
The solar panel frame, solar panel negative terminal, battery negative terminal, chassis and ground lug shall all be electrically connected together and grounded.
3.0 Operation
The solar engine shall be configurable as either dusk-to-dawn, 24 x 7 or wireless on-demand depending on the nature of the device being powered and the availability of the wireless control option.
The control module shall have a pushbutton that allows assignment of the solar engine to one airfield group from 1 to 8. The solar engine will only respond to control signals directed at its particular group number of which it is a member.
The solar engine shall be programmable via a USB connection to a PC with Windows operating system.
Depending on the programmed configuration, wireless on-demand control can activate either a 15-minute operating duration, or a pre-determined maximum time-out period for emergency events.
The solar engine’s control module shall offer diagnostic feedback indicators for battery status, system status, battery reverse polarity, and solar panel reverse polarity.
4.0 Environmental Specifications
The solar engine shall meet the following temperature requirements:
Operating:-30 °C to +50 °C (-22 °F to +122 °F)
Storage:-40 °C to +80 °C (-40 °F to +176 °F)
The solar engine, with its solar panel tilted for maximum angle relative to the ground, shall be capable of withstanding wind velocities up to 480 kph (300 mph) without damage.
Frangible couplings shall be FAA approved and meet the requirements for FAA frangibility including wind and mechanical loading.
The solar engine’s electronics shall have ingress protection IP66 against dust and jets of water.
The solar engine shall operate normally in humidity ranges from 0% to 100%
5.0 Approvals
The non-wireless and wireless solar enginevariants shall possess approval and/or certification of the following:
- WEEE and RoHS compliant
- Industry Canada ICES approved
- FCC approved
In addition:
- Non-wireless solar engine shall be CE compliant
6.0 Quality Assurance
The solar engine shall be manufactured in an ISO-9001 certified environment.
Excluding the batteries, the solar engine, including solar panel, electronics, mechanicals and associated components, shall be warrantied for a minimum of three years. The batteries shall be warrantied for 1 year.
7.0 Simulation Tools
Vendor must provide solar simulation tools for the solar engineto allow accurate country-wide visual simulation mapping of load performance versus intensity settings, usage, autonomy requirements, depth of battery discharge and all other common parameters of solar simulation.
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