Technical Specification for Freeze Protective Heating Cable System of Roof Rain Streams and Downpipes
A. General Features
- Heater wire or fabricated heater wire mesh system; It is a system that prevents the freezing of horizontal rain streams and vertical downpipes on the roofs, and ensures that the water formed as a result of the melting of snow and ice accumulated on the roofs is discharged from the connected pipes without any problems.
- In the design and applications of the system, priority should be given to human health, the safety of materials, and the maximum service life, and if any, domestic production should be the reason for preference.
- System materials; should be guaranteed for at least 10 years against design, production and application faults.
- The materials used in the system are expected to be suitable and resistant to weather conditions.
- Snow and ice detector panel and junction boxes must be in the appropriate protection class. The resistance of these materials to harmful ultraviolet rays is important. The standard of the connecting cables must be at least IP-65/66.
- System materials, which should allow maintenance and repair in winter conditions, must be used or can be used in similar applications.
- The system should only be activated in case of icing risk and should provide energy saving and prevent overheating.
- The heating cable system or the fabricated-assembled heating cable mesh system is installed by considering the cross-section and roof areas of horizontal rain streams.
- According to the roof area where water drainage will be provided, a power of at least 300 W/m2 and 350W/m2 should be taken as a basis for 1 m2 area, and the power of 1 meter of heater cable should not exceed 30W/meter linear power for silicon, flora insulated heater cables.
- This upper limit should not exceed 23W/meter for single conductor XLPE insulated heater cables and 28W/meter for double conductors.
- Heating cables used in vertical rainwater downpipes are lowered from the roof to the ground through the pipes in a way that does not cause obstruction. If the downpipes are connected to a manhole below the frost level, the heater cable is extended to below the soil frost level. This type of cables should be two conductors, fed from a single point, armored, fully grounded, and if possible, they should be reinforced with polyamide/aramid polymer rope inside or outside for breaking prevention purposes.
- The cables of the system and the energy cables feeding the system are located in the junction boxes on the roof. Cable connections are not made outside the box or in the open. In addition, all supply cables must be protected with spirals.
- Outdoor thermostat and snow / ice detector parts should be installed in suitable places so that they can detect even the most adverse weather conditions on the roof.
- Heating cables or fabricated heater nets used in the system should be fixed to the rain creek floor without screwing or gluing. Temporary, short-term solutions such as heat, cold and ultraviolet resistant tape, adhesive or silicone are strictly prohibited in the fixing process.
- After the necessary preliminary work, the details of the process are submitted to the approval of the administration and after the approval, the assembly application begins.
- After the installation of the system, the system is tested and delivered to the administration in a usable form.
- Necessary documents, information, maintenance and operating instructions and application projects related to the system are submitted to the administration in Turkish.
B. Heating Cables
- In the heater cable or fabricated heater mesh system; Series resistance resistance cables with a power of 30 w/m, pre- or fabricated termination, produced for snow / ice melting applications are used.
- Products produced in Turkey are preferred according to Turkish laws.
- The resistance wires of the cables must have the following features; metal braided, aluminum foil grounding conductor, silicone or fluoro-polymer inner insulation, halogenated XLPE or outdoor resistant engineering polymers should be used.
- Carcinogenic substances such as PVC should not be used for future generations or due to the weakness of the external environment.
- The cold cable at the end of the system cable must be at least 10 meters long and 1. Quality polyamide must be spiral protected.
- System cables or fabricated heater cable mesh must be under warranty for 10 (ten) years.
- Damages and problems caused by manufacturing and assembly errors must be replaced free of charge within 10 years.
- The commitment related to the scope of warranty is delivered to the administration by the contractor company as a condition of final acceptance of the work at the end of the work.
C. Snow/Ice Detector and Panel
- The snow / ice detector is a part of the system that will only be activated when there is a risk of icing.
- The detector must allow rail mounting within the panel. The detector must be able to operate independently of the sensor parts, thus allowing testing when needed.
- The sensitivity of the humidity sensor part on the detector should be adjustable between 0 and 100. The detector panel should be placed outdoors.
- It should be separate from the snow and ice detector and the temperature sensor, and the outdoor thermostat sensor parts should be placed in a suitable place on the roof to detect the most adverse weather conditions.
- Heating cables should be fed from the panel, and should not be fed directly from the snow / ice detector, regardless of its power. In addition, a suitable power contactor must be used.
- A 30 mA residual current switch with appropriate amperage should be located at the panel input.
- There will be terminals at the inputs and outputs of the panel and, if necessary, a terminal bridge.
- If the roof is multi-piece and the roof heater load is high, the heater cable load can be divided into more than one panel. In this application, instead of more than one snow / ice detector, a control circuit will be installed that allows more than one power contactor to be driven from one detector.
- Automatic control board; ice detector, fuses, contactor, residual current relay and other materials.
- The system has a wide adjustment range and setting options. The detector system will only activate when there is a risk of icing. It saves energy as long as it is not needed. A special relay with roof and floor sensors constantly monitors the status of the system and reflects it on the screen. The thermostat control unit consists of a temperature and humidity sensor.
D. Junction and Attachment Boxes
- The junction boxes of the system should have at least IP-65/66 protection class and be resistant to breakage and impact.
- Supply cable and heater cable must be connected in the box via terminals.
- If there is an energy cable outlet from one junction box to another junction box, special terminals with appropriate cross-sections of the manufacturer of the box should be used. If a row terminal is used in the box, the upper bridge of this terminal must be used.
- The inputs and outputs of the heater and energy cables to the box must be glanded. As an added safety precaution, the sealing of the unions after connections should be supplemented with ultraviolet-resistant, high-temperature silicone.
- Junction boxes will be placed so as not to damage the waterproofing on the roof.