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VärmeKabelTeknik Switchpoint heating – Communication

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Switchpoint heating – Communication VärmeKabelTeknik 2

Introduction PROPOSAL FOR A SWITCHPOINT HEATING CABLING SYSTEM

General Requirements

Each heater shall be fitted with a short flexible lead terminating in a 2‐pin plug. A modular wiring system shall be used to distribute power to the heaters. The system shall exhibit a very high degree of reliability and shall be able to fully withstand the hostile environment in which it is installed.

Plug and socket shall be such that

• the two can be easily and quickly mated

• they incorporate a sealing/retention device which, when the two are mated,

a) creates a waterproof seal

b) is unaffected by vibrations from whatever source

c) is capable of showing no evidence of separation when subjected to a static pull load of 50 N

The system shall be designed to operate satisfactorily in temperatures between ‐40°C and +60°C and in locations adjacent to the ends of railway points, which may be water‐logged and contaminated with chemicals. All equipment shall resist water, fuel, oil, lubricating oil, oxalic acid, weed‐killer formulations and de‐icing fluids.

Choice of Cable for Feeding to Control Panel

Cable harnesses, as well as 2‐core, 4‐core, 8‐core and 12 ‐core multicore cables shall have insulating material that is suitable for outdoor use. The sheath of the cables shall be of Polychloreprene (PCP), Polyurethane or other material with good abrasion resistance. The principal moulding material (with the exception of the conductor insulant) shall be Polychloroprene(PCP)/ Polyurethane or equal.

2‐ , 4‐ and 8‐Way Blocks for Strip Heating and Associated Clamp Lock Heaters

The mouldings of the 2‐, 4‐ and 8‐way blocks shall be solid and void free. The compound shall conform to BS 6899 and be of the ordinary‐duty, oil‐resistant, flame‐retardant type (E.M.2).

1.5mm² minimum 2‐way socket‐outlet blocks shall be 2‐pin, anti‐vibration, min. 10A rated and suitable for the plugs moulded on the heater leads of clamp lock heaters.

4‐and 8‐way socket‐outlet blocks shall be 2‐pin, anti‐vibration, minimum 10A rated and suitable for the plugs moulded on the heater leads of strip heaters.

All socket tubes shall be perpendicular to the end of the connectors. The socket outlets shall incorporate a seal arrangement to prevent the ingress of moisture and water.

The mating surfaces of the mouldings shall be smooth, accurate, free from all defects and excess materials in the form of flash etc.

The termination block shall have a multi‐conductor cable integrated with the block or fixed to give protection to at least IP67.

Strip Heaters ‐ Constant Wattage Heater ‐ Series Resistive Elements

All materials and equipment, including heaters and cables, must have a long service life and be able to function satisfactorily in the arduous environment in which they will be required to operate. Hazards will include severe and continuous vibration due to rail traffic, immersion in water and snow, contact with ice, weed killer formulations, diesel oils, lubrication oils, oxalic acid and de‐icing fluid.

Strip heaters shall be suitable for operation at up to 250V AC ± 10%, 50Hz, 2‐wire unearthed power supply. The power rating of the constant wattage or fixed heaters shall be 200 W/m ±3%.

Heaters are to be in standard lengths in accordance with drawing ±2%. Combinations of these standard lengths are used to heat point ends depending on the type of points involved.

The cross‐section dimensions of the heaters shall be a maximum of 16 mm x 9 mm.

The heaters shall be capable of being shaped by cold bending to a set of up to 90° ; the bending radius shall be limited to not less than 5 times the section dimension of the heater. The heaters' performance shall not in any way be affected by the shaping process.

The heaters shall be able to operate in ”free air”, totally or partially, without this affecting the length of their service life The heater element and its insulant shall be totally enclosed by a continuous sheath. The heater sheath material shall be Incoloy or Stainless Steel, Grade 321 to BS 970, Part 1, or an equivalent grade of Stainless Steel. Copper‐Nickel sheet on Incoloy. Self‐limiting elements and parallel constant wattage heaters shall have an outer jacket of FEP or better and must be double insulated.


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Each heater assembly shall identify the manufacturer, the batch and year of production. This information shall remain legible throughout the life of the assembly.

Strip heaters are secured to the rail by means of channels and rail clips.

Channels shall be of metal, not galvanized, compatible with the rail, conforming to SS 2333 or equal.

The heater sheath material shall be compatible with the rail clip material which is in contact with the channel.

Double‐Insulated Self‐regulating Strip Heaters,

Constant Wattage Heaters and Parallel Constant Wattage Heaters

All materials and equipment, including heaters and cables, shall be capable of ensuring a long service life and satisfactory operation in the arduous environment in which they will be required to operate. Hazards will include severe and continuous vibration due to rail traffic, immersion in water and snow, contact with ice, weed killer formulations, diesel oil, lubrication oils, oxalic acid and de‐icing fluid.

The heaters shall be suitable for operation at 110‐240V AC ±10% 50Hz, 2‐wire unearthed power supply. Maximum 110V AC ±10% 50Hz unless double insulated. The power rating of the heaters shall be greater than 100W/m at ‐10°C.

If no soft start is installed, the heater inrush current shall not exceed 3 times the steady state current and shall decay to within 5% of steady state current within 2 minutes.

The heaters, when installed on a point end, shall provide sufficient power to give a level of protection down to ‐ 20°C ambient temperature.

Heaters shall be supplied to the required length in the range 1 ‐ 20 metres. The cross‐section area of the strip shall not exceed 16 mm x 9 mm at any point along its length from the cable connection point to the end of the heater.

The heaters shall be capable of being shaped by cold bending to a set of up to 90° ; the bending radius shall be limited to not less than 5 times the section dimension of the heater. The heaters' performance shall not in any way be affected by the shaping process.

The heaters shall be able to operate in ”free air”, totally or partially without this affecting the length of its service life.

The heater element shall be totally enclosed by a continuous sheath. The heater sheath shall be of a fully electrically insulating material to a minimum of 600V A.C. & 1000V D.C. When installed, the heaters shall be mechanically protected by a channel of stainless steel, SS 2333 or equal.

Each heater shall be provided complete with a 2‐core lead. The lead shall be provided complete with a moulded‐on polyurethane or rubber 2‐pin 10A (or greater) rated anti‐vibration plug in accordance with the requirements stated in Section 7.

The connection arrangement for the heater lead to the element shall have the following properties:

• Provide satisfactory electrical connections and provide such connections with adequate mechanical protection.

• Provide adequate insulation of the electrical connection.

• Provide for satisfactory mechanical security of the lead in such a manner that if a force of 5N is applied to the lead, no strain is exerted on the electrical connection.

• The connection housing shall be filled with an insulating compound to prevent the entry of moisture and the risk of condensation.

The complete heater assembly, including the sheath, cable and electrical connections, shall be protected to classification IP67 in accordance with BS EN 650529.

Strip Heater Rail Clips

The rail clips shall be designed to secure electric strip heaters onto the rail points at an adequate pressure to ensure that optimum heat transfer is achieved.

The material of all the components comprising the rail clips shall be non‐deteriorating, have a long life and function satisfactorily in the arduous environment in which they will be required to operate. Hazards will include severe and continuous vibration due to rail traffic, immersion in water and snow, contact with ice, weed killer formulations, diesel oils, lubrication oils, oxalic acid and de‐icing fluids.

The range of rail clips required for each type of rail is detailed below:

Flat Bottom Rail. BS 11 Section No 113A

a) Stock‐rail heater clip b) Switch‐rail heater clip c) Stock‐ or switch‐rail heater connection clip



Bullhead Rail. BS 11 Section No 95 RHB

a) Stock‐ or switch‐rail heater clip b) Switch‐rail heater clip (toe) c) Stock‐ or switch‐rail heater connection clip

Flat Bottom Rail. UIC. 54A (Switched Diamonds Only)

a) Stock‐rail heater clip b) Stock‐rail heater connection clip

Flat Bottom Rail. UIC. 54B

a) Switch‐rail heater clip b) Switch‐rail heater connection clip

The rail clips shall be suitable for the retention of the channels.

The rail clips and channels shall ensure that good thermal contact is made between the heater and the rail. It shall also permit the expansion and contraction of the heater and the rail due to thermal effects.

Channels for Strip Heaters

Channels shall conform to SS 2333 or equal. Channels shall be shaped so that they bring the heating element as close as possible to the rail surface. The thickness of the channel walls must be minimum 1.0mm in order for the channels to have good stability.

4‐way connecting blocks are designed in such a way that the four terminal blocks go between two sleepers.

Velox heating elements have short connection cables with a cold tail of 20cm, the heated part depending on the length of the switch rail.

As a standard, the cables for the stock‐rail elements are 0,5 – 0,7m longer than the ones for the switch‐rail elements. It is important that these elements should be 0.5 – 0.7m longer as this will help the switch rail's two‐end heating situation.

In order to get increased heat for the stretcher bars there may be used stretcher bar heaters or – if extra heat input is needed due to temperature, wind etc. – a shorter element can be fixed to the inside of the stock rail. These elements are connected at the end of the stock rail by means of a female cord set.

Before placing the heating elements, the rail must be cleaned. This can be easily done by hand with a steel brush, or with a brush fitted to a drill.

Installation

Planning the switchpoint system.

There are many types of point, various suppliers or manufacturers of points, and different lengths of points. This makes some individual adaptation of the heating system to the switches in question necessary.

In England there is a standard range of switches. Experience shows that they have been equipped with lengths of element as shown in the below table.

Point Type Length of Heater Required (m)

Stock Rail Switch Rail

AV 4.26 3.91

BV 4.61 4.26

CV 5.32 4.97

DV 6.39 6.04

EV 8.16 7.81

FV 9.94 9.59

SGV 11.75 (6 + 5.75) 11.40 ( 6 + 5.40

GV 13.85 (6 + 7.85) 13.50 (6 + 7.50

HV 17.29 (8 + 9.29) 17.04 (8 + 9.04The next table shows standard elements that are a close match.

Point Type Heaters & Lengths

Required II

AV 4 x 4m 2 x 4 + 2x5m

BV 4 x 5m 2 x 5 + 2x6m

CV 4 x 5m 2 x 5.5 + 2x6.5m

DV 4 x 6m 2 x 6 + 2x7m

EV 8 x 4m 2 x 8 + 2x9m

FV 8 x 5m 2x10 + 2x11m

SGV 8 x 6m 2x12 + 2x13m

GV 4 x 4m & 8 x 5m 2x14 + 2x15m

HV 12 x 6m 2x18 + 2x19mIt is important that the switch rail should have the correct length. The stock rail shall be at least 0.5m longer, i.e. passing the toe end of the switch rail with 0.5m or more. It is easy to cut the Velox cables to the correct lengths.


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Find the Correct Clip for Your Rail Profile

It has proved difficult to find a clip that can be installed everywhere. Normally, the foot of the stock rail is the same size, 12mm approximately, regardless of the profile of the switch rail.

We usually heat the whole moving part of the switch. This can vary from 4m up to as long as 90m for high‐speed switches. The most common sizes for Railway switch rail are in the interval 10‐14m. The switch lengths of the Metro and regional trains, light rail, are shorter, 4‐6m.

For larger switches, 8m and above, the thickness of the switch rails is either 16‐18mm, 18‐20mm or 20‐22mm. We have therefore made 4 sizes of switch‐rail clips, as a standard. The cut‐out section in the rail of some switches serves to make the switch rail more flexible.

You will find drawings of clips in the Clips Section of this Catalogue.

Before installing, make sure you clean the surface of the rail using a brush or the like. At the toe end, cleaning may be difficult due to limited space, but try your best. Heat transfer is improved when the surface is clean.


System management / Yearly maintenance manual

The Velox Megapoint system is designed to give trouble free service for a design life of 20 years. All components within the system have been chosen from well known manufacturers and individually tested before use. During this time, it is possible that there will be software updates. These will be available from Velox.

We recommend a visual inspection of the system every year. The equipment should first be made safe by isolating the incoming supply before inspection. The following should be checked:

• Lock/handle mechanism,

• Door seals,

• Water/dust ingress,

• Cables securely in place,

• Earth bond in good condition,

• Heat damage,

• No weather station damage (if weather station fitted).

• A manual bypass switch is provided in the cabinet to switch on the point heating locally for test.

• If back‐up battery is fitted this should then be examinated for physical as well as electrical damage. Battery components should be inspected every year.

Battery

The weather station, if installed, has a 9V lithium battery. This battery shall be disposed of in accordance with regulations in force at the time of disposal. Replacement batteries can be bought from us or RS Components or some such supplier. You can also use a standard 9V battery, but be aware of the shorter life of such a battery.

If battery back‐up is used for a computer in the cubicle, this battery should be disposed of in accordance with the regulations in force at the time of disposal. Replacement batteries can be supplied by us or RS Components or some such supplier.

In addition, the system should be remotely tested twice a year. GSM/GPRS access to the system is by MCdialog VNC protocols. During this test, any alarms should be noted and the heating should also be set to operate. The current levels can be monitored to ensure that all heating elements are operational. After the test, the controller settings should be returned to their original state. If the heating elements cause tripping of the ELCB, the elements should be replaced.

The Velox Megapoint utilises temperature sensors to determine when the point heating should be switched on or off.

Test Procedure

1. First, put the cubicle together. 2. If a weather station (option) is to be included,

mount the weather‐station mast. 3. Mount the antenna directly in the cubicle roof. 4. Install the transformer, if one is to be included. 5. Fit the MegaPoint panel. 6. Fit a DIN rail for computer and modem (and

weather station, if this is an option). 7. Connect computer and modem (and weather

station, if any) to the MegaPoint panel. 8. Connect 8‐core cable for heating cable to the

respective terminal blocks. b) Heater or equal load should be applied.

9. Connect the temperature sensors to the respective terminal blocks.

10. Connect the incoming power supply. 11. Put the main switch to ON. 12. Make sure the earth leakage circuit breakers are

switched on (turned upwards). 13. Make sure the circuit breakers are switched on

(turned upwards). 14. Make sure the test switches are in the "Automatic"

position (turned upwards). 15. If all connections have been correctly made, the

modem pilot light should flash or have a fixed light, depending on the model.

16. Start the computer. 17. The lights on the triacs should now begin to flash. If

the ambient temperature is below 3 degrees centigrade, the lights will, after a while, change to fixed red. At temperatures above 3 degrees centigrade, the lights will instead go off.

18. In that case, you can either use MCdialogue to go in and temporarily increase the desired value for the installation

19. or do a manual test with the help of the test switches.

20. To test manually, put the test switch in the test position (turned downwards) and test each channel individually. This will also serve as a check of which point, and which cable, is connected to each particular channel.

21. After the manual test, be sure to put the test switches back in the "Automatic" position (turned upwards).

22. Fill in the form – test report. 23. Sign the test report located on the transparent

protection cover


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Telephone: +46‐301‐418 40 – Email: [email protected] – Homepage: www.vkts.se

Industrihuset Södra Hedensbyn 43

S‐430 64 HÄLLINGSJÖ S‐931 91 SKELLEFTEÅ

Sweden Sweden

Fax: +46‐301‐418 70 Fax: +46‐910‐881 33

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