HEAT DETECTORS FOR USE IN FIRE ALARM IS : 2175-1988

Indian Standard
SPECIFICATION FOR HEAT SENSITIVE FIRE DETECTORS FOR USE IN AUTOMATIC FIRE ALARM SYSTEM

IS : 2175-1988

(Reaffirmed 2000)

REAFFIRMED 2010

1. SCOPE

1.1

This standard covers the general requirements, test methods and performance requirements for heat sensitive (point) detectors for use in automatic fire alarm system.

2. TERMINOLOGY

2.0

For the purpose of this standard, the following definitions shall apply.

2.1

Control and Indicating Equipments—Unit(s) containing the controls, relays, switches and associated circuits necessary to:

1. provide power,
2. receive signals from alarm indicating (activation devices) and transmit them to the fire alarm devices and control for automatic fire protection equipment, and
3. electrically supervise the system circuitry.

2.2

Detachable Detector—A detector designed to be easily removed from its normal operating position for maintenance and servicing purposes.

2.3

Fixed Temperature Heat Sensitive Detector—A detector designed to operate when the temperature of detector exceeds a predetermined value.

2.4

Line Detector—A linear form of detector in which the detection process may take place anywhere along its length.

2.5

Non-Detachable Detector—A detector not designed to be easily removed from its normal operating position for maintenance and servicing purposes.

2.6

Non-Resettable (Non-Restorable) Detector—A detector which after response requires the renewal of component or components to restore it to its normal state of readiness to detect.

2.7

Point (Spot) Type Detector—A detector in which the sensing element is essentially of a compact area.

2.8

Rate of Temperature Rise-cum-Fixed Temperature Heat Sensitive Detector—A detector designed to operate within a given time:

1. when the rate of temperature rise at the detector exceeds a predetermined value regardless of the actual temperature, and
2. when the temperature at the detector exceeds a predetermined value.

2.9

Resettable (Restorable) Detector—A detector which after response and on cessation of the conditions that caused the response, may be restored from its alarm state to its normal state of readiness to detect without the renewal of any components.

3. TYPES AND GRADES

3.1

Heat sensitive detectors (both resettable and non-resettable) covered in this standard are of the following types:

1. Fixed temperature detector, and
2. Rate of temperature rise-cum-fixed temperature detector.

3.1.1

Each of the above detectors are subdivided into three grades based on the response time (see 5.2) as Grades 1, 2 and 3.

4. GENERAL REQUIREMENTS

4.1

The detector shall be provided with means for mounting (on ceiling/wall) securely and independent of any support from the attached wiring. The heat sensitive element(s) shall not be closer than 15 mm of the detector.

4.2

Plastic, if used, shall not start softening, deforming or melting at a temperature lower than 95°C

5. PERFORMANCE TEST AND CRITERIA FOR CONFORMITY

5.1

A sample of required number of detectors (see Tables 1 and 2) of each design selected randomly from production of not less than 200 detectors, shall be used for testing and shall be numbered. The test (one or more) shall be carried out in the order given in test schedule by the methods mentioned in Tables 1 and 2 and shall conform to the requirements given in 5.2 to 5.9. The detectors shall pass all the tests. All the tests are type tests which cover the production up to 10 000 numbers.

5.2

Directional Dependence and Response Time—Detector number mentioned in Table 1 or 2 (as applicable) shall be tested for these properties according to the method given in Appendix A and shall conform to the response time requirements for the three grades as given in Table 3 and in 5.2.1 (as applicable) in all orientations.

5.2.1

In case of ‘rate of temperature rise-cum-fixed temperature’ type detectors, the following requirement shall also apply additionally.

5.2.1.1

At rates of rise of air temperature less than l°C/min, the detector when tested according to the method given in Appendix A, shall be required to operate at an air temperature of not less than 58°C, and for Grades 1, 2 and 3 at not more than 65, 73 and 81°C, respectively.

5.3

Vibration—The detectors (see Table 1 or 2 as applicable for numbering and rate of temperature rise) shall be tested in the manner described in Appendix B and shall comply with its requirements.

5.4

Corrosion—The detectors (see Table 1 or 2 as applicable for numbering and rate of temperature rise) shall be tested in the manner described in Appendix C. They shall be deemed to comply with the test if:

1. For Four Days Corrosion—The response time of each detector remains within the

TABLE 1 TESTING SCHEME FOR RESETTABLE DETECTORS (Clauses 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 5.10, 5.11, A-3.1, B-1.1 and D-1.1)
Test Procedure		Detector Number										Rate of Rise (°C/min)							Remarks
Clause	Test	1	2	3	4	5	6	7	8	9	10	1	3	5	10	20	30	0.2
5.2, A-2	Directional dependence	1													x				8 orientations Two tests at each rate : one with most favourable orientation, other with least favourable orientation. With least favourable orientation
5.2, A-3	Time of response	1	2								x x	x x	x x	x	x x	x x	0* 0*
5.2. A-3	Response before test			3	4	5	6	7	8	9	10		x			x
5.3	Vibration			3	4
5.4	Corrosion, 4 days Corrosion, 16 days Corrosion, Salt spray				4			7	8	9	10
5.5	Shock					5	6
5.6	Low temperature	1	2												x
5.7	High temperature		2											x		x
5.8	Supply voltage variation		2
5.9	Insulation resistance	1																	Tests at both rates at upper and lower limits of supply voltage Measurement of resistance only With     least    favourable orientation
5.10	Humidity	1
5.11	Ageing (applicable to fusible link type only)	1											x
A-3	Response after test	1		3		5		7	8	9	10			x
			2		4		6		8		10
*Only for dercctors subject to testing under 5.2.1 and 5.2.2.

2.  

TABLE 2 TESTING SCHEME FOR NON-RESETTABLE DETECTORS (Each detector or element for one of the test only) (Clauses 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 5.10, 5.11, A-3.1, B-1.1 and D-1.1)
Test Procedure		Element or Detectors Number	Rate of Rise (°C/Min)							Remarks
Clause	Test	1 to 8	1	3	5	10	20	30	<0.2
5.2, A-2	Directional dependence	1 to 8				x				8 orientations
5.2, A-3	Time of response	9 to 22 23 to 36	x x	x     x	x x	x x	x x	x x	0* 0*	Two tests at each rate : one with most favourable orientation, other with least favourable orientation
5.3	Vibration	37 to 38
5.4	Corrosion, 4 days Corrosion, 16 days Corrosion, Salt spray	39 to 40 41 to 42          38
5.5	Shock	43 to 44
5.6	Low temperature	45 to 46
5.7	High temperature	47			x
5.8	Supply voltage variation	48 to 51		x		x
5.9	Insulation resistance	52								Measurement of resistance only
5.10	Humidity	53		x
5.11	Ageing (applicable to fusible link detectors only)	54		x
A-3	Response after test	37, 39, 41, 43, 45 38, 40, 42, 44, 46		x x						With least favourable orientation
*Only for detectors subject to testing under 5.2.1 and 5.2.2.

3.  

TABLE 3 ACCEPTANCE LIMITS FOR RESPONSE TIME (Clause 5.2)
Rate of Rise of Air Temperature	Lower Limit of Response Time for All Response Grades		Upper Limit of Response Time for
			Response Grade 1		Response Grade 2		Response Grade 3
D°C/min	min	s	min	s	min	s	min	s
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)
1	30	0	37	20	45	40	54	0
3	08	13	12	40	15	40	18	40
5	04	09	7	44	9	40	11	36
10		30	4	02	5	10	6	18
20		22-5	2	11	2	55	3	37
30		15	1	34	2	8	2	42

d.  limits of its grade with an additional tolerance of ± 15 percent or 10 whichever is greater.

5. For Sixteen Days Corrosion—(Sulphur dioxide and salt spray)
1. Each detector gives an immediate continuous fault signal on connection to its C & I equipment, or
2. Each detector gives an alarm signal in time which does not exceed the upper limits of response grade 3.

5.5

Shock—The detector (see Table 1 and 2, as applicable for number and rate of temperature rise) shall be tested in the manner described in Appendix D. They shall be deemed to comply with the test if:

1. no alarm is given when they are subjected to the specified shock; and
2. any change in response time of the detectors after the test when compared with the response time obtained before the test does not exceed 15 percent or 10 s, whichever is greater.

5.6

Low Temperature—Response time of detectors (see Table 1 or 2, as applicable for numbering) shall be put inside a suitable chamber/tunnel/enclosure and connected to its control and indicating equipment. Air temperature in the chamber shall then be reduced to a minimum of 0 ± 1°C at a rate not exceeding l°C/min. The detector shall be kept in the condition of minimum temperature for 1 h to allow its temperature to stabilize. After 1 h stabilization, the detector shall be taken out and kept at a temperature of 27 ± 3°C for 5 to 6 h and then response times measured (see Appendix A), one at 3°C/min rate of temperature rise and the other at 20°C/min rate of temperature rise using least favourable orientation. Detectors shall be deemed to comply with this test if:

1. no alarm is initiated during the test, and
2. any change in response time of the detectors measured after the test when compared with the response time obtained before the test does not exceed 15 percent or 10 s, whichever is greater.

5.7

High Temperature—The detector (see Table 1 or 2, as applicable for numbering/rate of temperature rise) shall be mounted in the tunnel in its normal operating condition with its normal fastenings. Keeping the detector energized and disconnected from control and indicating equipment, temperature of air flow in the tunnel shall be raised to 50°C at a rate not exceeding 1°C/min. The temperature at this level shall be maintained for 1 h. The detector shall then be energized and the response time shall be measured (see Appendix A) at 5°C/min rate of temperature rise using the least favourable orientation. The detector shall respond within a time not exceeding 11 min and 36 s for Grade 3, 9 min and 40 s for Grade 2, and 7 min and 44 s for Grade 1.

5.8

Supply Voltage Variation—The detector (see Table 1 or 2, as applicable for numbering/rate of temperature rise) shall be tested and response times measured as described in Appendix E. They shall be deemed to comply with this test if, as a result of supply variation, when compared with the response time obtained before and after the test does not exceed 15 percent or 10 s, whichever is greater and shall not give false alarm during the test.

5.9

Insulation Resistance—The detector (see Table 1 or 2, as applicable) shall be mounted in its normal operating condition with its normal area fastening on a metal plate of at least 2 mm thickness and having surface area at least 5 times the mounting surface of the detector. With the plate shorted to ground terminal of the voltage source, voltage shall be applied between the plate and the terminals of the detector which are inter-connected. In 5 s, voltage shall be applied to a maximum of 500± 10 volts DC. The maximum voltage shall remain applied for one minute. Insulation resistance shall then be determined. Thereafter, it shall be subjected to a temperature of 43 ± 2°C and relative humidity of 90 ± 3 percent for 10 days. After conditioning, the detector shall be kept at room condition for one hour. The insulation resistance shall be measured again. The detector shall be deemed to comply with the test if the resistance in first measurement before the exposure is not less than 10 M? and in second measurement after the exposure is not less than 1 MΩ, and the detector shall not give a false alarm during the test.

5.10

Humidity—The detector (see Table 1 or 2, as applicable) shall be kept inside a suitable humidity climatic chamber and connected to its control and indicating equipment. Following climatic conditions shall be created inside the test chambers:

Temperature	:	30 ± 2°C
RH	:	80 ± 5 percent
Duration of exposure	:	7 days

The detector shall be transferred to tunnel within 1 hour of removal from the chamber and its response time measured according to Appendix A. The time measured after the exposure and before shall not differ by a factor greater than 16 and the detector shall not give false alarm during the test.

5.11

Ageing (Applicable to Fusible Alloy Link Type)—The detector (see Table 1 or 2, as applicable) shall be placed in a suitable temperature oven and exposed for a period of 90 days to an ambient air temperature which is 15°C below the rated operating temperature of the detector but not less than 50°C. Following the exposure, the detector shall be allowed to cool for not less than 5 hours. After cooling, the detector operating temperature shall be ascertained according to Appendix A. The detector shall operate within a temperature rangeT ± (0.035 T + 062) °C.

Note—T°C is rated operating temperature.

6. INFORMATION

6.1

Sufficient information shall be given with the detectors to facilitate their correct application. Such information shall include broad details of general and technical features of the detector, correct monitoring position, reference to owners manual, operation of test feature (if provided), maintenance instructions, required electrical interface with the control and indicating equipment which may take the form either of the values of current, voltage, etc, and their allowable tolerances or a restriction of the detector to be used only in conjunction with specified control and indicating equipment, etc.

7. MARKING

7.1

Each detector shall be legibly and indelibly marked with the following:

1. Manufacturers name or trade-mark;
2. Type and description of detector and number;
3. Year of manufacture;
4. Grading of detector which shall be clearly indicated either by the colours as mentioned below, or by other suitable means;
1. Grade 1 : green
2. Grade 2 : yellow
3. Grade 3 : red; and
5. Whether provided with fusible link.

7.2

Each detector may also be marked with the Standard Mark.

Note—The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Act 1986 and the Rules and Regulations made thereunder. The Standard Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well defined system of inspection, testing and quality control which is devised and supervised by BIS and operated by the producer. Standard marked products are also continuously checked by BIS for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of the Standard Mark may be granted to manufacturers or producers may be obtained from the Bureau of Indian Standards.

APPENDIX A
METHOD OF TEST FOR TIME OF RESPONSE AND DIRECTIONAL DEPENDENCE (Clauses 5.2, 5.2. 1.1, 5.6, 5.7, 5.10, 5.11 and Tables 1 and 2)

A-1. APPARATUS

A-1.1

The response time and directional dependence shall be measured in a wind tunnel specified in Fig. 6 of IS : 9972–1981*. The air velocity in the tunnel shall be 0.8 ± 0.1 m/s and the air temperature shall be 28°C.

*Specification for automatic sprinkler heads.

A-1.2

The detector shall be mounted in its normal operating position on a board forming part of the ceiling of the working section of the tunnel so that it is symmetrically disposed with respect to the side walls of the tunnel, possibly in least favourable mounting position. The air temperature shall be measured by suitable thermocouple (copper-constantan wire not exceeding 025 mm in diameter, junction consisting of a half twist with tightly tinned joint). The temperature measuring device shall be approximate, at the same distance from the ceiling of the wind tunnel as the sensitive element of the detector and approximately 230 mm from the sensitive element against the flow of air in a horizontal direction. Before the test, the temperature of the air stream and the detector shall stabilized at 28°C. The temperature control of the tunnel shall be such that the temperature may be varied at 1, 3, 5, 10, 20 and 30°C/min with air temperature within the tunnel being at all times within ± 3°C of that required by the set rate of change of temperature, and also such that the temperature can be raised from 52°C at a rate not exceeding 0.2°C/min to a temperature of 83°C.

A-2. DETERMINATION OF DIRECTIONAL DEPENDENCE

A-2.1

The detector(s) shall be connected to its control and indicating equipment and tested in an air stream having a constant mass flow, equivalent to a velocity of 08 ± 0.1 m/s at 28°C and with a uniform rate of rise of air temperature of 10°C/min. Eight such tests shall be made, the detector being rotated about a vertical axis by 45° between successive tests so that the tests are made with eight different orientations.

A-2.2

The least favourable and most favourable orientations giving the greatest and the least time delays, respectively, between the initiation of the temperature rise and the operation of the detector shall be recorded.

A-3. TIME OF RESPONSE MEASUREMENT

A-3.1

The detectors, the response times of which are to be measured as mentioned in Tables 1 and 2, shall be connected to the indicating equipment and shall be tested in an air stream having a constant mass flow equivalent to a velocity of 0.8 ± 0.1 m/s at 28°C and having uniform rates of rise of air temperature 1, 3, 5, 10, 20 and 30°C/min (as applicable). The scheme of tests for various detectors is given in Tables 1 and 2. The time interval between the initiation of temperature rise and the operation of detector shall be recorded to an accuracy of 0.5 s and shall be designated as the time of response.

A-4. FIXED TEMPERATURE OPERATION

A-4.1

Two detectors shall be tested as in A-3 with a rate of rise of air temperature not exceeding l°C/min until the air temperature reaches 50°C and thereafter with a rate of rise of air temperature not exceeding 0.2°C/min. One of the detectors shall be in less favourable and the other in most favourable orientation. The air temperature at the operation of the detectors shall be recorded.

APPENDIX B
VIBRATION TEST (Clause 5.3 and Tables 1 and 2)

B-1. PROCEDURE

B-1.1

The detector (see Table 1 or 2, as applicable for numbering/rate of temperature rise), connected to its indicating equipment, shall be mounted in its correct operating position and response time (see Appendix A) shall be noted and then the detector shall be put on a vibration table. The test shall then be subjected to a vertical vibration of amplitude 0.1 mm for a period of 5 minutes at each of the following frequencies:

10, 15, 20, 25, 30, 35, 40, 45, and 50 c/s.

B-1.2

The operation of the detector or resonance of any component shall be noted. If resonance occurs, the detector shall be vibrated at the resonant frequency for a period of one hour. If no resonance occurs, the detector shall be vibrated at 50 c/s for one hour.

B-1.3

No fault or alarm warning shall be indicated and no mechanical defect (including the breakage/displacement of sensitivity seal, if provided) shall be visible during or after the tests as in B-1.1 and B-1.2. The time of response of two detectors shall be determined after the test. The change in response, before and after the test shall not exceed 15 percent or 10 s, whichever is greater.

APPENDIX C
CORROSION TEST (Clause 5.4 and Tables 1 and 2)

C-1. PROCEDURE

C-1.1

At least 15 cm of connection wires/cables prescribed by the manufacturer shall be connected to each detector or socket. When specific types of wires/cables are not prescribed for connection, a 138 mm diameter (or nearest equivalent) single copper wire, untinned, shall be used for connection leads in this test. The lowest point of the detector shall be between 25 and 50 mm above the liquid surface. A guard shall be provided to prevent drops of liquid from falling into the upper surface of the detector.

C-1.2

The detector (see Table 1 or 2 as applicable for numbering) shall be subjected to a corrosion atmosphere of Sulphur dioxide saturated with water vapor and maintained at temperature of 45 ± 3°C. The apparatus shall consist of a 5 litre glass beaker fitted with a cover, an electric heater, and a thermostat which can be set at 45 ± 3°C and copper tubing for flow of cool water round the beaker.

The thermostat shall be placed 140 mm above the bottom of the beaker. A hole is to be provided in the lid for the insertion of the thermometer. The corrosion atmosphere shall be produced by placing in beaker, a solution containing 20 g of sodium thiosulphate (Na₂S₂O₈.5H₂O) in 500 ml of water. The detector shall then be suspended in beaker and 10 ml of acid consisting of 156 ml of normal sulphuric acid (H₂SO₄) per litre of aqueous solution shall be added twice daily. During the test, the temperature near the detector shall be maintained at 45 ± 3°C by the heater and the thermostat and water flow in cooling coil shall be so regulated that the temperature at the outlet does not exceed 30°C. Where a test is intended to last for more than 8 days, the detector shall be removed after 8 days and the beaker emptied and cleared. A further 20 g of sodium thiosulphate in 500 ml of water shall be put in the beaker, the detector replaced and the corrosive atmosphere produced and maintained as before for a period of 8 days again.

C-1.2.1

The first pair of detectors shall be mounted in the beaker and exposed to corrosive atmosphere for a period of four days. Sixteen days exposure shall be given to the third detector. After prescribed exposures, the detectors shall be removed and allowed to dry for seven days, in normal room environment without disturbing the connections and the response time of detectors shall be measured as in Appendix A.

C-1.3

Salt Droplet Test—This test shall be conducted on the fourth detector. The detector shall be suspended with its lower edge 5 to 75 cm above the surface of water in a large dish and the whole shall be enclosed by a box-like cover. Once daily for a total period of 16 days the detector shall be removed, sprayed over its whole surface by a spray of sea water of the following composition and replaced under this cover;

Sodium chloride, g/l	23
Sodium sulphate, g/l	8.9
Magnesium chloride, g/l	9.8
Calcium chloride, g/l	1.2

The temperature throughout the test shall be maintained at 27 ± 2°C. After 16 days, the detector shall be removed and allowed to dry. It shall then be connected to its normal indicating equipment using the corroded lead and the response time shall be measured as in Appendix A.

APPENDIX D
SHOCK TEST (Clause 5.5)

D-1. PROCEDURE

D-1.1

The response time of the detector (see Table 1 or 2, as applicable for numbering/rate of temperature rise for test) shall be determined. A detector incorporating electrical contacts shall be mounted on a piece of 10 × 5 cm hardwood resting on edge on solid supports spaced 1 m apart. The test shall be made with the detector in the following two positions:

1. At the midpoint on the horizontal under side, and
2. At the midpoint on the vertical side.

D-1.2

A metal block of 35 kg mass shall be dropped on to the midpoint of the 10 x 5 cm timber from a height of 30 cm above the top horizontal surface of the timber. The detector shall be connected in circuit corresponding to its normal operation during the test and shall not operate as a result of shock.

D-1.3

After the test, the time of response of the detectors shall be determined (see Appendix A) :

APPENDIX E
SUPPLY VOLTAGE VARIATION TEST (Clause 5.8)

E-1. PROCEDURE

E-1.1

When upper and lower limits of supply voltage are prescribed, detector(s) shall be tested at both the limits. At upper limit, two tests shall be carried out and similarly two tests shall be conducted at the lower limit. When one nominal value of supply voltage is prescribed, two tests shall be carried out with voltage to control and indicating equipment reduced as 85 percent of nominal value (to be treated to lower limit) and further two tests with voltage increased to 110 percent of the nominal value and the response time measured (see Appendix A). In each pair of tests, one test shall consist of the measurement of response time with a rate of rise of 3°C/min and the other with a rate of rise of 20°C/min. The response times shall be recorded. For resettable detectors, the same detector shall be used for all the tests of E-1.1. For non-resettable detectors, a separate detector or detector element shall be used for each of the tests of E-1.1.

NFPA 72 - Heat Detection

Heat detectors work by detecting a temperature change or a high temperature limit. There are several types of heat detectors, including fixed-temperature, elevation rate, and combination detectors that use both types of sensing.

👉🏻Fixed-temperature heat detectors operate by activating an alarm when a predetermined temperature limit is reached. For example, a heat detector can be configured to trigger an alarm when the temperature in a room reaches 57 °C (135 °F).

👉🏻Rate of increase heat detectors operate by detecting rapid temperature increases. These detectors will activate an alarm if the temperature rises too quickly, even if the temperature does not reach a predetermined limit. For example, a rate of increase detector can be activated if the temperature in a room rises by 15 °F (8 °C) in a minute.

👉🏻Combined heat detectors use fixed temperature and rate of rise sensors to provide more comprehensive fire detection. These detectors are often used in areas where fires can develop rapidly, such as kitchens and boiler rooms.

Heat detectors use different technologies to detect temperature, including thermocouples, thermistors, and infrared sensors.

👉🏻Thermocouples and thermistors work by measuring changes in electrical resistance that occur as the temperature changes. Infrared sensors detect changes in infrared radiation emitted by objects as they heat.

Once a heat detector detects a temperature change or a high temperature threshold, it will activate an alarm or alert system, such as a strobe light or voice alarm, to alert occupants of the potential fire risk.

Benefits of choosing XLPE cable for Fire

Today, we all know the vast range of cables. LT Power Cable, Fire Survival Cable, Submersible flat cable and much more. The names can vary but almost all of these cables have one thing in common. A Conducting metal, an insulation material, and a sheath.

XLPE or better known “Cross-linked Polyethylene” have the feature of excellent insulation.

Basically, it is polyethylene. Polyethylene has crosslink’s which join the individual polymer chains together. Polythene has several applications in the modern world.

However, it has a low melting point.

This low melting point is covered by the cross-linking polymer chains. The cross linking’s helps in increasing the melting point. This and other cross-linked synthetic materials, of which EPR (ethylene propylene rubber) is a notable example, are being increasingly used as cable insulants for a wide range of voltages.

XLPE has many qualities which make it extremely useful for cable insulation. It is flexible permitting smaller bending radius for the cables. It is light weight and water proof. It is also tough which minimizes the need for armoring.

Cross-linking is the effect produced in the vulcanization of rubber and for materials like XLPE the cross-linking process is often described as ‘vulcan- ization’ or ‘curing’. Small amounts of chemical additives to the polymer enable the molecular chains to be cross-linked into a lattice formation by appropriate treatment after extrusion.

It is easier to handle and store compared to cables with paper insulation or lead insulation.

XLPE is considered to be the material of choice due to its ease of processing and handling, although paper / oil systems have a much longer history of usage and much more information on reliability exists.

Benefits of XLPE Cables

1. Electrical and Physical Properties

XLPE cable is known for providing an excellent electrical & physical property. It makes these cables best to use in transmission & distribution lines.

2. It can carry large current

Electricity travels in cables & wires. XLPE cables provide better thermal and aging property.

These special properties make any cable to carry currents under different temperature for long period of time.

3. Ease of Installation

Besides having the ability to stand under different temperature. It is very easy to install too.

As these cables are flexible and light in weight.

4. No need to stress over height and maintenance

Better insulation, better conductive metal provides these types of cable durable and flexible.

Now, it is easy to install these cables anywhere without stressing over height & route issues.

These type of cables do not possess oil, so it needs low maintenance.

5. No Need of Metallic Sheath

Sheath protects cables from external and internal forces at times.

However, In the case of XLPE cables, you need not worry about any metallic sheath or protection.

6. Excellent Protection

An XLPE cable gives an excellent mechanical, electrical, waterproof and radiation resistance.

It is best to use the XLPE insulated cables for electrical connection in line, lead wire of the motor, signal control line, locomotive wire, mining environmental protection cable, subway with shipping, nuclear power laying cable, firing X – ray high voltage line, TV high-voltage wire, and power transmission.

BS 5467 specifies construction and requirements for XLPE and EPR-insulated wire-armoured cables for voltages up to 3.3kV. The construction is basically similar to that of PVC cables to BS 6346, except for the difference in insulant. Because of the increased toughness of XLPE the thicknesses of insulation are slightly reduced compared with PVC.

The standard also covers cables with HEPR (hard ethylene propylene rubber) insulation, but XLPE is the material most commonly used. From 3.8kV up to 33kV, XLPE and EPR insulated cables are covered by BS 6622 which specifies construction, dimensions and requirements.

Conclusion:

Be sure to choose quality products, as choosing quality wires can help in the continuous flow of electricity.

·        Higher Current Rating.

·        High Short Circuit Rating.

·        Longer Service life.

·        For a short time it can withstand maximum 130°C and is favourable to endure short Circuit stresses.

·        It is less sensitive to the setting of the network protection.

·        Because of the thermosetting process taking place due the effect of cross linking, the crack resistance is increased.

·        Due to the chemical cross-linking internal stresses are reduced. Consequently the material is less sensitive during manufacturing process to the setting of the cooling gradient.

·        The thermal resistivity of cross linked material is favorably low, compared to the thermoplastic material.

·        The low dielectric loss is significant advantage.

·        The excellent mechanical features of the insulation improve the protection against external effects.

·        The resistance of the XLPE to acids, alkalies is outstanding and is often compensating the adverse environmental influences.

My recommendation, your application is Low / High always approve XLPE Cable in place of PVC.

Exit Route as on OSHA

OSHA’s Means of Egress Requirements, 1910 Subpart E

Do your employees know how to escape in an emergency? Do you have enough exits for prompt evacuation? Have your exit routes, discharges and accesses been properly designed and constructed?

The Occupational Safety and Health Administration’s (OSHA’s) emergency evacuation requirements are contained under Subpart E of the General Industry Standards, 29 Code of Federal Regulation (CFR) Part 1910.

Under the umbrella of Subpart E, employers will find OSHA’s requirements for exit routes, as well as their standards for both emergency action and fire prevention plans. In addition to OSHA’s emergency egress requirements, employers must be cognizant of the emergency egress requirements of their local fire department. Local fire departments and Fire Marshals will typically be enforcing the emergency evacuation requirements of the National Fire Protection Association (NFPA). The local Fire Marshal or fire department inspector is considered to be the local Authority Having Jurisdiction (AHJ). And as noted below, OSHA recognizes compliance with the NFPA’s egress guidelines as meeting OSHA’s standards.

OSHA breaks down their exit route requirements within Subpart E as follows:

• Compliance with Alternate Exit-Route Codes (1910.35),
• Design and Construction Requirements for Exit Routes (1910.36), and
• Maintenance, Safeguards, and Operational Features for Exit Routes (1910.37).

In addition, under 1910.34, OSHA provides definitions related to egress. It’s here that the scope of the Subpart E is called out under 1910.34(a), where it states that every employer within general industry is covered by the requirements, with the exception of mobile workplaces such as vehicles or vessels.

Alternate Exit-Route Codes

OSHA recognizes some employers may be following the emergency evacuation requirements of other regulatory agencies. It acknowledges and accepts this under 1910.35 where it states, “OSHA will deem an employer demonstrating compliance with the exit-route provisions of NFPA 101, Life Safety Code, 2009 edition, or the exit-route provisions of the International Fire Code, 2009 edition, to be in compliance with the corresponding requirements in 1910.34, 1910.36, and 1910.37.” Both the NFPA 101: Life Safety Code® and the International Fire Code were last updated in 2015.

Design and Construction Requirements for Exit Routes, 1910.36

A couple key definitions are important to understand prior to reviewing OSHA’s emergency egress design and construction requirements. These definitions are found in 1910.34:

• Exit – means that portion of an exit route that is generally separated from other areas to provide a protected way of travel to the exit discharge. An example of an exit is a two-hour fire resistance-rated enclosed stairway that leads from the fifth floor of an office building to the outside of the building.
• Exit Access – means that portion of an exit route that leads to an exit. An example of an exit access is a corridor on the fifth floor of an office building that leads to a two-hour fire resistance- rated enclosed stairway (the Exit).
• Exit Discharge – means the part of the exit route that leads directly outside or to a street, walkway, refuge area, public way, or open space with access to the outside. An example of an exit discharge is a door at the bottom of a two-hour fire resistance-rated enclosed stairway that discharges to a place of safety outside the building.
• Exit Route – means a continuous and unobstructed path of exit travel from any point within a workplace to a place of safety (including refuge areas). An exit route consists of three parts: The exit access; the exit; and, the exit discharge. (An exit route includes all vertical and horizontal areas along the route.)
• High Hazard Area – means an area inside a workplace in which operations include high hazard materials, processes, or contents.
• Occupant Load – means the total number of persons that may occupy a workplace or portion of a workplace at any one time. The occupant load of a workplace is calculated by dividing the gross floor area of the workplace or portion of the workplace by the occupant load factor for that particular type of workplace occupancy. Information regarding the "Occupant load" is located in NFPA 101-2015, Life Safety Code, and in IFC-2015, International Fire Code.

Under 1910.36, OSHA covers the basic design and construction requirements for exit routes and offers additional details in the following areas:

• Number of exit routes needed
• Exit discharge requirements
• Locking considerations for exit doors
• Design requirements for exit doors
• Capacity and size requirements for exit routes
• Considerations for outdoor exit routes

Exit routes must be a permanent part of the workplace and exits themselves must be separated by fire resistant materials. In facilities where an exit connects three or fewer stories, the materials used to construct the exit must have a one-hour fire-resistance rating; for four or more stories a two-hour fire- resistance rating is required for exit construction materials.

In addition, openings to an exit are limited to only those from occupied areas of the workplace or into the exit discharge. All openings into an exit must be protected by a self-closing approved fire door that remains closed or automatically closes in an emergency. The fire door, frame and hardware must be listed or approved by a nationally recognized testing laboratory.

At least two exit routes must be available unless the number of employees, size of the building, its occupancy or the arrangement of the workplace is such that all employees would be able to evacuate using a single exit route. Where more than one exit route is present in a workplace, they must be located as far away from each other as possible to prevent all egress routes from being blocked by smoke or fire during an emergency. More than two exit routes must be available if the number of employees, the size of the building, its occupancy, or the arrangement of the workplace is such that all employees would not be able to safely evacuate during an emergency.

As noted in the definition above, the exit discharge must lead to a space with access to the outside. It must also be large enough to accommodate the anticipated number of building occupants likely to use it. And if it contains stairs that continue beyond the level at which the exit discharge is located, it must contain a door, partition or some other effective means to clearly indicate direction of travel leading to the exit discharge.

An exit route door cannot be controlled by any mechanical device that could fail causing the door to lock. Employees must be able to open the exit route door from the inside at all times without the use of keys, tools or special knowledge. The only exception to this would be exit route doors in correctional or mental health facilities. In those types of high security settings, supervisory personnel must be on duty at all times to ensure the facilities emergency egress plan can be safely implemented should the need arise.

In addition, exit route doors must be side-hinged. And if the room that the exit door is servicing is designed to be occupied by more than 50 people or is considered a high hazard area, the side-hinged door must swing out in the direction of egress travel.

Exit routes must support the maximum permitted occupant load for each floor served and the capacity of the exit route cannot decrease in the direction of travel toward the exit discharge. The ceiling of an exit route must be at least seven feet six inches high with any projection down from the ceiling not reaching less than six feet eight inches from the floor.

An exit access must be at least 28 inches wide at all points. And where there is only one exit access leading to an exit or exit discharge, the width of the exit and exit discharge must be at least equal to the width of the exit access. The width of an exit route must be sufficient to accommodate the maximum load capacity of each floor served by the route. Objects that project in must not reduce the width of the exit route to less than the minimum width required for the exit routes.

If an outdoor exit route is used, it must:

• Have guardrails to protect unenclosed sides if a fall hazard exits;
• Have a covering if snow or ice is likely to accumulate along the exit route;
• Have a reasonably straight design with smooth, solid and level walkways, and
• Not have a dead-end longer than 20 feet.

Maintenance, Safeguards, and Operational Features for Exit Routes 1910.37

During new construction, as well as facility repairs and alterations, employees cannot occupy a workplace until exit routes are in place and accessible. And during construction, repairs or alterations, employees must not be exposed to the hazards of flammable or explosive substances or equipment that are beyond the normal permissible conditions in the workplace, or that would impede egress.

Exit routes must be arranged so that employees will not have to travel toward a high hazard area, unless the path of travel is protected from the area by partitions or physical barriers. The exit routes must be free and unobstructed, and if they’re not “substantially level” (1910.37(a)(3)) stairs or a ramp must be provided. Also, exit routes must be kept free of explosive or highly flammable furnishings and the safeguards designed to protect employees during an emergency, such as sprinkler systems, alarm systems, fire doors, exit lighting etc., must be in proper working order at all times.

Exit access cannot go through a room that can be locked to reach the exit or exit discharge, nor can exit access lead into a dead-end corridor.

Proper lighting and marking of the exit routes are vital. Each exit route must be adequately lighted so that an employee with normal vision can see along the exit route, and each exit must be clearly marked by a sign that reads “Exit.” Each exit route door must be free of decorations or signs that can obscure the visibility of the exit route door.

If the direction of travel to the exit is not immediately apparent, signs must be posted along the exit access indicating the direction of travel to the nearest exit and exit discharge. Additionally, the line-of- sight to an exit sign must be clearly visible at all times. Should there be a doorway or passage along the exit access that could be mistaken for an exit, it must be marked as “Not an Exit,” or be identified by a sign indicating its actual use.

Exit sign requirements are detailed in 1910.37(b) (6) and 1910.37(b) (7). OSHA does not specify a mandatory color for exit signs. What they do state is:

• Each exit sign must be illuminated to a surface value of at least five foot-candles (54Lux) by a reliable light source and distinctive in color. Self-luminous or electroluminescent signs that have a minimum luminance surface value of at least .06 footlamberts (0.21 candela/square meter (cd/m2)) are permitted.
• Each exit sign must have the word “Exit” in plainly legible letter not less than six inches (15.2 centimeters (cm)) high, with the principal strokes of the letters in the word “Exit” not less than three-fourths of an inch (1.9 cm) wide.

If there are flame retardant paints or solutions used along the exit routes, they must be reapplied as necessary to maintain their fire retardant nature.

Emergency Action Plans and Fire Prevention Plans 1910.38 & 1910.39

As indicated above, 1910 Subpart E also covers the employer’s requirements for both emergency action and fire prevention plans. For those employers who are uncertain whether they need an emergency action plan, OSHA’s created an easy to use and interactive eTool. Among the resources in The Evacuation Plans and Procedures eTool, is an “Expert Systems” tab. This tab includes a series of questions that allow employers to determine whether their facility requires an emergency action plan.

Commonly Asked Questions

Q.		Is there a requirement for exit sign color? Some facilities have Green, other facilities have Red.
A.		There is no OSHA requirement for specific colors, however, OSHA states it must be distinctive in color from the background. NFPA 101 Section 7.10.1.8 states "Every sign required in Section 7.10 shall be located and of such size, distinctive color, and design that it is readily visible and shall provide contrast with decorations, interior finish, or other signs." Some states or local jurisdictions may require a certain color. Always best to check with your local AHJ.
Q.		When is a "No Exit” sign required?
A.		Under 1910.37(b) (5), OSHA states, “Each doorway or passage along an exit access that could be mistaken for an exit must be marked “Not an Exit” or similar designation, or be identified by a sign indicating its actual uses (e.g. closet).” The NFPA does specifically reference the "No Exit" verbiage under NFPA 101 Section 7.10.8.3.1. They state "NO EXIT" sign is needed where, "any door, passage, or stairway that is neither an exit nor a way of exit access and that is located or arranged so that it is likely to be mistaken for an exit.”