F1202 TRACE HEATING. Road & Ramp

Transcription

1 Trace Heating Specialists Road & Ramp

2 ROAD & RAMP HEATING ESH Trace Heating Ltd provide a comprehensive range of products to prevent the settlement of snow and formation of ice on roads, ramps and stairs. The two main protection systems utilised by ESH are: Parallel Circuit Constant Wattage Parallel Circuit Self Limiting The parallel circuit heating systems are CUT-TO-LENGTH to allow on-site flexibility and no wastage. The use of parallel circuit heating allows flexibility of the system to suit application design requirements and is not restricted by size and shape of the surface. The application of the heating system can be modified on-site to enable full and uniformed coverage across the heated surface due to any design modifications or site restrictions etc. JBP 240V SUPPLY ETO (BY OTHERS) JBP HEATING CABLE SENSOR CABLE (in conduit) INTERCONNECTING CABLE (BY OTHERS) IF REQUIRED CABLE TIES/STRIP ETOG SENSOR Page 1 of 7

3 SYSTEM TYPE - PREVENTION [RECOMMENDED] To prevent snow settlement and ice formation at a constant minimum ambient of -15ºC a system loading of approximately 180 watts per m 2 is required. Utilising cable rated at 30w/m at 150mm spacing equivalent to approximately 7m of heating tape per m²spacing allows excellent uniformity of the system across the surface to be heated. Even distribution of the heating system gives better thermal conductivity which not only ensures that no areas of the surface are liable to cold spots but does not stress the system which decreases the chance of product failure due to over stress SYSTEM TYPE MELT OUT To enable the system to MELT-OUT snow build-up a system loading of approximately 300 watts per m 2 would be required. NOTE: this would only be a requirement if the system was manually shut-down enabling the build up of snow and ice, and is of course a function of snow depth. The extra energy is necessary to cover the latent heat required to convert snow or ice to water. Utilising cable rated at 40w/m at 125mm spacing equivalent to approximately 8m of heating tape per m² spacing allows excellent uniformity of the system across the surface to be heated. Page 2 of 7

4 PARALLEL CIRCUIT CONSTANT WATTAGE Bus-Wire Conductors Insulation Soldered Joint Heating Element Outer Sheath Over Braid Over Jacket Parallel circuit heating tape is designed to be cut from reel lengths and site terminated to suit application. The heating tape consists of a number of short heating zones, each connected across a pair of continuous bus-wire conductors. Each complete heating zone will give its full rated design output with circuit voltage applied to the bus-wire conductors. System continuity can tested to ensure that full system output is fully functional. CONSTRUCTION The heating tape has a core comprising two bus-wire conductors contained within an extruded silicone rubber sheath. The sheath is notched on alternate sides at predetermined intervals to expose a short section of bus-wire conductor. Nichrome resistance wire is wrapped at regular spacing around the core as a continuous conductor, making contact with the bus-wires at the exposed points. After completion of the heater conductor wrapping, a high temperature soldered joint is made at each contact point ensuring that a number of conductor strands are securely bonded to the bus-wires. An extruded outer sheath of silicone rubber is then extruded over the core and heater element to complete the internal heater tape assembly. The heating cable is fitted with an earth protection braid and over-jacketed with an extruded silicone rubber sheathing. SPECIFICATION Conductors Copper stranded flexible 30/0.25mm (1.5mm²). Core Silicone rubber. Heater element Nickel/chrome 80/20 Solder High melting point 296 C. Outer Sheath Silicone rubber. Width 12.0mm. Thickness 7.0mm Heater zone 0.5 or 1m according to design output Braid Plated copper Temperature Min. 60 C Max. 200 C Standard To BS 6351 Grade 2.1. Min Bend Radius 50mm ELECTRICAL Heater Zone Heater Zone Insulated Bus-wire end Rated Voltage Rated Voltage 220V/240V or 110V/120V AC/DC. Heater Zone (according to design) 0.5/1.0m. A 30mA trip Residual Current Circuit Device (RCCB) or Earth Leakage Circuit Breaker (ELCB) is recommended for use with heating tapes. Page 3 of 7

5 PARALLEL CIRCUIT SELF LIMITING Bus-Wire Conductors Semi-conductive Self Limiting Core Insulation Multi Strand Earth Lead Foil Earth Screen SELF REGULATING HEATING TAPE FOR FROST PROTECTION AND TEMPERATURE MAINTAINING A parallel resistance, cut to length on site self regulating heating tape cable designed for frost protection, process pipework maintaining and hot water temperature maintaining. Self Limiting heating tape adjusts heat output to equal the heat loss. As temperature falls due to decreases in external or internal temperature, output increases. As temperature increases as a result of increasing external or internal temperature so output decreases. CONSTRUCTION The heating tape has a core comprising two bus-wire conductors contained within an extruded semi-conductive self limiting heater core with an outer insulating polyolefin sheath. The tape has an earth protection screen in the form of a Foil Jacket covering a multi strand earth lead. The tape is finished with a further protective thermoplastic outer sheath over the earth screen. Over Jacket (OJ) SPECIFICATION Conductors Copper stranded flexible Thickness 3.2 mm 1.23mm². Braid Foil jacket with multi strand Earth lead Core Semi-conductive Polymer. Over sheath Thermo-plastic elastomer Outer Sheath Polyolefin. Weight 6kg/100m unbraided Width 10.1mm. 7.8kg/100m braided Circuit Breaker type C to EN V Type 15A 20A 30A 40A FBT FBT FBT Table shows circuit breaker size for circuit length (m) for start up at 5ºC Page 4 of 7

6 INSTALLATION Heating tape is laid in longitudinal runs either flat or on edge and secured to the reinforced mesh using cable ties at maximum 600mm intervals. The reinforced mesh be securely fitted and at the correct depth to allow the heating system to be positioned at approx 50mm below the surface of the concrete 600mm Max fixing 150mm Spacing 75mm from edge of heated area The heating tape is laid on edge through bends. Heating tape should be spaced approximately 75mm from the ramp edges. Do not lay heating over expansion joints. Consideration should be taken to allow for 1-2m of extra heating system to enter covered areas to eliminate any snow or ice formation due to snow or water carried in on vehicles or by foot traffic. Ensure that maximum circuit length of the heating cable is not exceeded. Pre-punched fixing strip should be used if there is no steel mesh reinforcement. Ensure that all ends are protected from moisture ingress at all times. During and following installation ensure that the cable is not subjected to pedestrian or vehicular traffic. Page 5 of 7

7 TESTING Test all heating cable: Prior to installation Following Installation During Concrete Pouring Following Pouring Depending on the type of heating cable installed, the following tests must be carried out and recorded. IMPORTANT All electrical testing and system checking should be carried out by an electrician or other competent person(s). Drawings/Sketches/Photos Should be taken of the installation All tests should be carried out at every stage of the installation All results should be recorded and signed-off at every stage of the installation CONSTANT WATTAGE - Maintenance The system will operate automatically via the thermostatic or temperature control set point. No maintenance of the system is required but it is recommended that the system is checked for operational and electrical integrity periodically or prior to the winter. With electrical supply disconnected the electrical resistance of the trace heating section can be measured by Ohms law i.e V 2 = Total Watts R Loading, in watts can be verified by checking the values on the acceptance certificate. Insulation Resistance should be tested using a 2500Vdc tester and should record a resistance reading of <20MΩ to ensure that there is no damage to the heating cable. SELF LIMITING - Maintenance The system will operate automatically via the thermostatic or temperature control set point. No maintenance of the system is required but it is recommended that the system is checked for operational and electrical integrity periodically or prior to the winter. With electrical supply disconnected Insulation Resistance should be tested using a 2500Vdc tester and should record a resistance reading of <20MΩ to ensure that there is no damage to the heating cable. Page 6 of 7

8 SYSTEM CONTROL The system may be controlled via an air sensing thermostat set to 3/5ºC. This will switch on the heating regardless of whether moisture or precipitation is present. For efficient operation a Type ETO-1550 Thermostat with moisture detection and temperature sensor Type ETOG- 55 Ground Sensor should be used to ensure that: The heating system will only be energised when moisture/precipitation is present at low temperature. TYPE ETO 1550 ETO-1550 is a thermostat for economical control of snow-melting systems in outdoor areas, gutters and down pipes. Cold temperatures do not necessarily create ice unless moisture is present. The ETO detects both the outdoor temperature and moisture, and the snow-melting system will normally only be energised when snow or ice occur. ETO is used for control of electric heating cables as well as other heat sources. SPECIFICATION Supply voltage 230 VAC ±10%, Hz Built-in transformer 24 VAC, 6 VA 3 output relays (volt-free contact) 10A, 10A, 16A On/off differential 0.3 C Temperature range 0/+5 C Scale adjustment potentiometer for sensor calibration Built-in timer for manual snow melting 1-6 hours Detection mode MOIST CONTROL: - Position ON Moisture and temperature - Position OFF only temperature Ambient temperature 0/+50 C Housing/incl cover IP 20 / IP 21 Weight 495 g Dimensions H/W/D 90/156/45 mm Page 7 of 7