Sunday, September 7, 2008

Malaysian Wiring Code MS1979:2007 is Now Mandatory!

Wiring Standards & National Wiring Codes

With the adoption of the MS/IEC60364 "Wiring Installation for Building" in 2000, Malaysia, in conformity with other countries in the region are practitioners of a common wiring standard (China and Vietnam in particular are strong proponents of the IEC wiring standard). As the IEC60364 is drafted by a multi-lateral, international body, which was (and still is, though less so) Eurocentric in nature, the IEC60364 has to accommodate the multiple conditions of various (European) national standards. Due to this the IEC60364 tend , of necessity, to be performance-based in nature. By comparision the U.K. IEE 17th edition or BS7671 "Regulations for Electrical Installation", and U.S.A. NEC 2008 "National Electrical Code©" (or NFPA 70) tend to be prescriptive-based as these standards are compiled specifically for only one country.

After the publication of the MS/IEC 60364, Suruhanjaya Tenaga, convened an industry-wide work group sometime in 2003 to draft a national wiring code. This WG on national wiring, chaired by The Electrical and Electronics Association of Malaysia (Ir. Rocky Wong Hon Tang) has as their working brief:

  1. To draft a national wiring code suited for Malaysia and not in conflict with current laws and regulations ('Electricity Supply Regulations').
  2. To ensure compliance with MS/IEC60364.
  3. To consider particular aspect of wiring practice NOT included in the MS/IEC60364 (principally prescriptive-based rules).
  4. To provide a safety guide principally for residential installations catering to 'uninformed' consumers (who make up more than 80% of electricity consumers).

After 3 years of draft and public consultations and 2 more years of public gazette the following documents are now published:

  1. MS 1979:2007 "Electrical Installation of Buildings – Code of Practice"

  2. MS 1936:2006 :Electrical Installation of Building – Guide to MS IEC 60364"

The public announcement by Suruhanjaya Tenaga can be viewed in this circular dated 1st July 2008. This circular makes it mandatory that the Garis Panduan Pendawaian Elektrik (GPPE) (or "Guides to Electrical Wiring") be a basis for all wiring in residential buildings. The GPPE in turn takes as its basis MS1979, MS1936 and MS/IEC60364, a circuitious way of announcing that the 'cart' (GPPE) is the principal document which actually is powered by the 'horse' (MS1979 and MS1936).

MS 1979 – Quick Brief

As this post DO NOT propose to be a scholarly oevre on wiring installation (please PAY to attend seminars and workshops conducted by TEEAM, ACEM and IEM), I have to be of necessity brief. I will touch on the important points of the Code here.

The structure of MS1979 is a simple distillation of all the important prescriptions contained in MSIEC60364 which have direct relevance to wiring in residential buildings. Rule-based conditions are set-out in the MS1979 where only performance-based requirements are listed in the MSIEC60364. The final product is a very simple booklet containing individual "COP" (Code Of Practice) numbered COP1 to COP91.

The companion to the MS1979 is MS1936 which has a more expanded scope compared to the MS1979 as it covers all other L.V. installation under the MS60364.

A quick list of COP which are important for designers and installers are as follows:

  1. COP05 – All metal enclosures of electrical appliances must be connected to a protective conductor. Water, gas pipes, strucutural metal parts of the buildings and ductings of airconditioning system must also be connected to the main equipotential bonding.
  2. COP06 – Isolation on fault. Protection using RCD, fuse, CB etc. must comply with Ra x Ia < 50V

    Ra = Resistance of earth electrode & protective conductor;

    Ia = operating current of protective device (sensitivy of RCD and 5s current trip for inverse time relay).

    50V is the safe contact voltage defined by IEC60749-1.

  3. COP07 –Earthing resistance must be less than 10Ω for operation of RCD but resistance of less than 1Ω is targetted.

  4. COP08 – Electrical equipment must be mounted within materials that can withstand temperatures produced (by the equipment).
  5. COP10 – Water heaters or forced air heaters or steam generators must be equipped with over heating devices (i.e. use o/t cut-out etc.).
  6. COP12 – In > IB,
  7. COP13 – Iz > In
  8. COP14 – I2 < 1.45 x Iz

    In = nominal current of protective device; IB = design current; Iz = current capacity of cable ; I2 = tripping/effective operation current of protective device.

  9. COP16 – Requires determination of short circuit current within the installation. Effectively this requires every TNB district engineer to issue information on short circuit at the point of common coupling (PCC) at the locality of installation.
  10. COP19 – Surge Protection Device (SPD) is RECOMMENDED for supply from overhead lines.
  11. COP26 – Bending radius of 12 times diameter of cable is mandated. This effectively requires that elbows and junctions be used where cable changes direction.

    In Malaysia, many wiring installation WILL FAIL THIS CRITERION.

  12. COP27 – Space factor for conduit shall be 40% and for trunking shall be 45%.
  13. COP28 – Cables installed behind walls (i.e. embedded in concrete) shall be horizontal or vertical parallel to the edges of the room and within 150mm from top and 150mm from edge of wall.

    In Malaysia, many wiring installation WILL FAIL THIS CRITERION as cables are commonly installed diagonally fully and in many cases partially (picture 1).

  14. COP30 – Wiring within ceiling space (under roof) must be provided with mechanical protection (i.e. installed within APPROVED conduit). In addition they must be installed either parallel or perpendicular to the edges of the wall.
  15. COP31 – Water heater circuits shall have 2-pole switch installed at suitable location. At the vicinity of the heater a socket outlet is required (unswitched is acceptable).
  16. COP32 – Air Conditioner circuits shall have socket outlet (unswitched type is accepable) at vinity of unit.
  17. COP35 – Size of neutral conductor must be same size as phase conductor.
  18. COP36 – Size of neutral conductor may be reduced (reference to COP35) at the discretion of the Professional Design Engineer (i.e. only a P.Eng can decide).
  19. COP39 – Minimum cable size shall be 1.5mm² copper or 2.5mm² aluminum. Therefore the practice of using 1.25mm² copper cables is illegal!

    Note: The use of aluminum cables WITHIN BUILDING is a FIRE HAZARD and should be carefully considered by the specifying engineer. India which has the most prevalent practice of using aluminum cables recommends that only cables above 50mm² may be aluminum.

  20. COP41 – Allowable voltage drop is 4%. Voltage drop for motor starting may be 10%.
  21. COP42 – Soldered connections to connect or terminate cables ARE NOT ALLOWED (see COP43 below).
  22. COP43 – Connections of 2 lengths of conductors shall be by sockets and crimping.
  23. COP44 – Cables for final sub circuit shall NOT BE JOINED.
  24. COP51 – RCD (or current type ELCB) for single phase installation shall not exceed 100mA (the previous quoted in the regulations was 30mA).
  25. COP52 – RCD for 3-phase installation shall not exceed 100mA. Three units of single pole type RCD instead of a 3-phase RCD may be used PROVIDED no 3-phase load(s) is/are served.
  26. COP53 – Hand-held equipment shall have RCD not exceeding 30mA.
  27. COP54 – RCD not exceeding 10mA shall be installed for special location (places of public entertainment; wet places; protection of electric water heaters).
  28. COP56 – Requires RCD to be regularly tested, at least twice a year.
  29. COP59 – It is recommended to place SPD before RCD (on the supply side), see figure 2.
  30. COP61 – SPD should be rated not less than 5kA.
  31. COP64 – The minimum earth connection from SPD to main earth terminal shall be not less than 10mm² copper and shall be as short as possible (0.5m).
  32. COP65 – Every circuit shall be provided with means of isolation.
  33. COP67 – Semiconducting devices shall not be used for isolation. Therefore a 'soft' switch must be backed up with a 'physcial' switch.
  34. COP70 – Earth electrodes may be round copper sheathed steel rods, copper tapes of conductors, rods or pipes or steel bars of reinforced concrete foundations of buildings. The last option (rebars in foundation) is becoming a favourite option for many designers but however must be designed, specified and installed by experienced practitioners.
  35. COP71 – Water or gas pipes ARE NOT allowed to be used as the sole means of earthing but equipotential bonding is permitted.
  36. COP72 – Requires earthing system to be checked annually
  37. COP73 – Earthing conductor buried in soil and without protection against corrosion shall be minimum 25mm² bare copper. This value may be reduced to 16mm² copper if protection against corrosion is present. Note: standard copper tape at 25mmx3mm complies with this requirement.
  38. COP74 – Connection of earth conductors buried in ground using exothermic weld is recommended. Connections to earth electrodes which require periodic inspection at earth pit/chambers may be clamp type. Note: In the author's eperience many Malaysian contractor use braze joint which is NOT ACCEPTABLE.
  39. COP76 – Protective conductor shall be (a) same size as line conductor if less than 16mm² (b) 16mm² if line conductor is more than 16mm² and up to 35mm² (c) half size of line conductor if more than 35mm².
  40. COP77 – Protective bonding conductor to main earth terminal shall not be 6mm² for copper or 16mm² for aluminum.
  41. COP78 – Neutral of standby system shall be separate when in operation.
  42. COP79 – Overcurrent for essential services (e.g. fire fighting pumpsets) may be waived. Overcurrent protective devices if provided, may provide alarm only.
  43. COP82 – Supervision of work on LV single phase installations shall be under direct responsibility of Wireman (single phase or 3-phase restriction). The Wireman shall certify completion under Form G.
  44. COP83 - Supervision of work on LV 3-phase installations shall be under direct responsibility of Wireman (3-phase restriction). The Wireman shall be required to certify completion under Form G.
  45. COP 84 – Testing for single phase installation shall be by Wireman (single-phase or 3-phase restriction) under Form H.
  46. COP 85 – Testing for 3-phase installation shall be by Wireman (3-phase restriction) under Form H.
  47. COP86 – Other installation at higher than low voltage shall be tested by a Electrical Services Engineer under Form H.
  48. COP87 – Electricity SHALL NOT BE CONNECTED until Forms G & H are submitted by the owner or building operator.
  49. COP88 – Insulation measurements shall be carried out on LV installation using dc voltages. Where 500Vdc is applied, the insulation resistance shall be more than 1MΩ.
  50. COP91 – Every completed installation shall have as-built electrical diagrams prominently displayed. Diagrams shall be endorsed by the professional design electrical engineer.

    Note: All P.Eng who are submitting officer under CCC should take note of Form H and G requirements under COP 82 to 85 and electricity connection under COP87.

Sunday, August 31, 2008

Index – Are you Designing Fire Alarm System in Accordance with the Code?

In this series of posts, I am republishing a paper I presented in a seminar held in K.L. on 22nd July 2004.
Fire detection and alarm as passive system is the most commonly prescribed system for fire protection. The types of system available ranges from the simplest one or two point manual alert system to the most complex detection, monitoring and alarm system with interlinks to central monitoring stations and building automation and security systems.

Under current procedures on 'Certification of Completion and Compliance' (CCC), the submitting person is obligated to design and (in the final 'act of CFO certification) installed in conformity to acceptanble codes and standards. It is therefore incumbent on the submitting professional that he be proficient in technical standards and codes on which he claims to have conform with.

This series is structured into the following parts:

  1. Abstract and Introduction
  2. Overview of BS5839-1 and NFPA72
  3. Circuit Design and Survivability
  4. Appendix B – Circuits By Class and Style NFPA 72-2002
  5. Power Supply, Emergency Supply, Fail Safe Supply
  6. Cable Types, Fire Tests of Cables and Installation Practice
  7. Fire Tests – Figures 3 to 12
  8. Conclusion & Trends

Are You Designing Fire Alarm System In Accordance with the Code – 6


Trends in fire safety standards
The evolution of fire codes has seen steady and increasing sophistication in terms of practice and application. This trend is due to the increasing mass of information made available from research and forensic studies of failures and tragedies. Some trends which can be discerned can be listed as follows:

(a) Though prescriptive-based codes will still predominate in codes and standards, performance based codes will see increasing influence.

(b) Prescriptive codes will also be increasingly modified to include multiple scenario instead of simple scenario in the past. Prescriptive codes with a larger choice of scenario should not by confused with performance-based approach.

The reasons for this trend are:

(1) Harmonisation of codes (a growing international movement linked to globalisation trend) will force standards to be written on a generic basis with lee-way for multiple scenario to take into account deviations due to national conditions and practice).

(2) Increasing information and data available will enable a richer view of possible design scenarios.

(3) Increasing complexity of building projects demand more comprehensive solution.

(4) New considerations such as environmental concern and preservation of heritage are much more important issues than they use to be.

The trend above will however demand that the design or installation engineer responsible for fire safety have a higher standard of technical (and interpretation) ability. Simpler prescriptive codes of earlier times will now be more complex with higher number of parameters to contend with.

New MS1745 – Part 14 "Fire Detection and Alarm System" A working group under the supervision of Technical Committee on 'Dry Fire Protection System' is currently working towards a Malaysian Standards on Fire Detection and Alarm System. The WG has been working since 2006 and the full document be published (hopefully) in 2008. Perhaps I can get the chairman of the WG (Ir. Wong See Fong ( to write a short blog on this standard in future.

Unresolved topics It can sometimes be asserted that increasing knowledge generate more question. This can be illustrated by ongoing debate over the efficacy of fire tests currently specified in cable standards, pitching cable manufacturers and standards organisation against each other (principally European-American). It is expected that specification of fire test for cables will see the most changes in the near future.

Concluding with a caveat on unfinished issues not included
As can be noted in this presentation, other issues (e.g. voice alarm system, types of detectors, type of controllers etc) pertaining to fire alarm system are not included in this presentation. The topics covered in this paper, by itself however, shows more complexity than the Consulting Engineer (in Malaysia) would be normally aware of. It is hoped that practitioners will take note that the science of Fire Safety as a multi-disciplinary engineering science warrants more attention than currently being allocated.


(1) NFPA70:2002 "National Electrical Code";

(2) NFPA72:2002 "National Fire Alarm Code";

(3) BS5839-1 : 2002

(4) "Fire Performance of Data Communication Cables" published by the Fluoropolymer Division, Society of the Plastics Industry, Inc, Washington DC (

(5) "Fire Testing of Electrical Cables for Public Transportation" Marcelo M. Hirschler, GBH International, California.

(6) "New Developments in Fire Safety Requirements for Communication Cables in North America and Europe" 2002, Draka USA (

(7) "Highlights of the New NFPA 72-2002" in 8 parts by Dean K. Wilson, P.E.

Go back to Index

Are You Designing Fire Alarm System In Accordance with the Code – 5A

Cable types, Fire Tests of Cables, and Installation Practice

Are You Designing Fire Alarm System In Accordance with the Code – 5

Cable types, Fire Tests of Cables, and Installation Practice

Fire resistance or enhanced cables receiving increase attention. Cables are the communication pathways between components of the fire alarm system and comprise the following class:

~~Low voltage cable system, typically power supply cables to control panels (110V, 1-phase or 240V, 1-phase or 415V, 3-phase)

~~Extra low voltage (ELV) cable system, typically for data, signalling or device power-line cables at less than 50Va.c. or 110Vd.c.

With the notion of linking issues of fire safety and circuit integrity or survivability, fire rating of cables are now receiving increasing attention from both codes. Both codes though not providing detail explanation of fire ratings, cross-referenced other codes which have relevance to fire rating of cables. Information on fire rating of cables and the specification of fire rated cables bear some difference in opinion between the European standards (which is also the IEC standards) and the North American ANSI/UL standards. This section will include an explanation of fire rating of cables which are not found within BS5839-1 and NFPA72 themselves.

BS5839-1; prescription for cables
The 2002 edition of BS5839-1 contains major upgrade to the 1988 edition by recommending fire resistant cables. Fire resistant cables are now extended to include two types (1) Enhanced and (2) Standard. The following recommendations are included as follows:

~~Clause 26 now specify that all cables must comply with existing requirements of BS6387, EN50200 PH30 (standard) or EN50200 PH120 (enhanced).

~~All system cables including LV mains supply to the panel to be fire resistant.

~~Standard fire resistant cables should be considered sufficient to meet the effects of fire with suitable jointing and support.

~~Enhanced cables are recommended in:

(1) Non-sprinkler buildings with more than four phases of evacuation.

(2) Non-sprinkler buildings of greater than 30 metres in height.

(3) Where the critical interlinking paths might be affected in unsprinklered linked buildings with occupancy requiring supervised evacuation or some difficulty in evacuation e.g. hospital.

Notes: In case (3) above, standard cables may be used if network loops provide the 'interlink' and such loops have start and return routed separately. In such case, the network loop is said to declassify the interlink as 'critical' .

(4) Where following risk assessment enhanced cables are deemed necessary.

~~Cable support system shall match the fire rating and performance of the cables. In practice this may require examination of plastic ties, trunking or clips which may act as critical components of the support system and which may not be suitably fire rated.

~~No external joints shall be used. Where junction boxes are not avoided, they shall be labelled "Fire Alarm" and match fire resistance rating of the cables.

~~Standard cables installed below 2m height require mechanical protection unless surface clipped to strong construction in relatively benign environments e.g. offices shops etc.

~~All conductors should have minimum cross sectional area of at least 1mm² and if stranded a minimum cross sectional area of 0.5mm².

~~Segregation of wirings:

(1) fire alarms should be segregated from other services in separate conduit or trunking.

(2) Where multicore cables are used none of the other cores should be used for other purposes.

(3) Mains cables should be segregated from system cables outside and inside the panel. They should not enter the panel at the same point.

~~Fire cables should be a single common colour throughout a building to aid identification, e.g. red. Figure 3 – Fire Rated Cables to BS5839-1 2002 .

Fire rating of cables in NFPA72 is cross referenced to NFPA70 (NEC)
In NFPA72 only two paragraphs described wiring requirements with a cross-reference to NFPA70 (National Electrical Code). This cross referencing however opens a wide topic related to cable types and fire performance rating based on North American (NFPA, UL and ANSI) standards. The following tabulation list Articles in NFPA70 (NEC) which are relevant.

Table 1 – Cable types and Fire Tests (North American)

Article 760 – Fire Protection Signalling System


Fire Test


Power limited fire alarm cable for general purpose fire alarm use.

UL 1581 Vertical Tray Flame Test


Power limited fire alarm riser cable for use in vertical riser shafts

UL 1666 Riser Flame Test


Power limited fire alarm plenum cable for use in ducts and air plenums

UL 910 Steiner Tunnel Test

Article 770 – Optical Fiber Cables and Raceways


Non conductive and conductive optical fiber plenum cables suitable for use in ducts, plenums and other environmental air spaces.


Non conductive and conductive optical fiber riser cables plenum suitable for use in vertical run in shaft or from floor to floor


Non conductive and conductive optical fiber cables suitable for general purpose use except in vertical risers and plenums.


Non conductive and conductive optical fiber cables suitable for general purpose use except in vertical risers, plenums and spaces used in environmental air.

Article 800 – Communications Cables and Raceways


Communication plenum cable listed as being suitable for use in ducts, plenums and other spaces for environmental air


Communication riser cable listed as being suitable for use in vertical run in shaft or from floor to floor


General purpose communication riser cable listed as being suitable for general purpose use except in vertical risers and plenums.


Communication cable listed as being suitable for use suitable for general purpose use except in vertical risers and plenums.


Limited use communication cable suitable for use in dwellings and raceways


Undercarpet communication cables suitable for undercarpet use

Note: CSA C22.2 No. 0.3M (Canadian Standard Association) defines resistance to the spread of fire is for the damage (char length) not to exceed 1.5 m (4 ft 11 in.) when performing the vertical flame test for cables in cable trays.

Details pertaining to segregation of cables similar to BS4839-1 (section 5.2) and measures for the mechanical protection of cables are included in NFPA70. Articles 760, 770 and 800 however contain more details pertaining to such installation measures compared to BS5839-1.

Fire Tests to European / British Standards

An understanding of fire tests on cables is essential before designers and installers can select the correct type of cables in compliance with the code. As British Codes and Standards are harmonising towards European Codes (EN), a description of the fire test for EN and BS can be taken to be similar. Table 2 describes the test listed under the hierarchy cables specified under BS5839-1.

Table 2 – List of Fire Tests under British Standards

BS6387:1994 CWZ

Fire Resistance, with and without water and mechanical shock; Specification for performance requirement for cables required to maintain circuit integrity under fire conditions:

Cat. C Exposed to Fire @ 950ºC. for 3 hours

Cat. W

(1) Expose to fire @ 650ºC for 15 mins., then

(2) Expose to fire @ 650ºC with water for 15mins.

Cat. Z

(1) Expose to fire @ 650ºC for 15mins., then

(2) expose to fire @ 650ºC. with mechanical shock for 15mins.

EN50200 BS5839-1:2002 Fire Performance Cable
Standard Grade BS5839-1:2002 - PH 30

PH30 (30 mins)

(1) Exposed to fire @ 830ºC. for 15mins., then

(2) exposed to fire @ 830ºC. with water & mechanical Shock for 15mins.

The temperature may vary +40 / - 0 deg. C

(Test No 2. is not detailed within EN50200 PH30 but is covered in BS5839-1:2002, Clause 26.2-D)

Enhanced Grade BS5839-1:2002 - PH 30

PH120 (2 hours)

(1) Exposed to fire @ 950ºC. for 60mins., then

(2) exposed to fire @ 950ºC. with water & mechanical Shock for 60mins.

The temperature may vary +40 / - 0 deg. C (Test No 2. is not detailed within EN50200PH120 but is covered in BS5839-1:2002, Clause 26.2-E)

BS7629-1 BS7629-1 E1 BS7629-1 E2

Specification for 300/500V Fire Resistant Electric Cables.; Having low emissions of smoke and corrosive gasses when effected by fire (Multi Core Cables)

BS4066-1-15.5, Cat. S

Fire Performance; Test on Electric Cables Under fire Conditions

BS7622 Cat.S Replaced By BSEN50268-2:2000 BSEN50268-1:2000

Smoke Emissions; Common test methods for cables under fire conditions, Measurement of smoke density of electric cables burning under defined conditions.

BS 6387 Tests by fire, water and mechanical shock. This test is used to determine capability of cables to maintain circuit integrity under fire conditions. Additional conditions of water and mechanical shock are applied for grading of capability of cables. Code used to designate capability of the cables are as follows:

Resistance to fire


650ºC for 3 hours


750ºC for 3 hours


950ºC for 3 hours


950ºC for 20 minutes


Resistance to fire & water


650ºC for 15mins. then for 15min with fire and water


Resistance to fire with mech. shock


650ºC for 15mins. with 30 seconds hammer blow


750ºC for 15mins. with 30 seconds hammer blow


850ºC for 15mins. with 30 seconds hammer blow


Figure 4 – Fire Resistant Test; Figure 5 – Resistance to Fire and Water; Figure 6 – Resistance to Fire and Hammer Blows;

IEC 60331 Fire Tests This test is used to determine whether a cables can maintain circuit integrity during and after exposure to fire.

A sample of cable is exposed to fire for 3 hours at a temperature of between 750ºC and 800ºC while energised. After 3 hours the fire is extinguish and the circuit turned off. A duration of 12 hours is allowed before re-energising the cable and checking for circuit integrity.

IEC 60332-3 – Flame Propagation Tests
This test defines the ability of bunch cables to restrict flame propagation when laid in trunking, cable trays or conduit. The tests comprises 3 categories each determined by the amount of combustible material in a 1 m sample.





Litres of combustible material in a 1 metre sample




Exposure to fire in minutes




The cable sample are placed vertically next to one another on a vertical tray where they are exposed to fire from a ribbon gas for the duration of exposure. After burning, the samples are wiped clean to examine for char on the surface of the cable. Charring should not reach a height exceeding 2.5m above the bottom edge of the burner. Figure 7 IEC 60332-3 Flame Propagation Test

IEC 61304 Smoke Density Test
This test measures the smoke emission from cables during a controlled fire. The test sample is burn in a chamber measuring 3m cubed The amount of smoke emission is measured by a light beam-photocell which measures the opacity of the smoke.
Figure 8 – Smoke Density Measurements

North American Standards on Fire Tests

The main fire tests recognised by the North Americas are the following:

  • UL VW1 – Single Cable Burner test

  • UL 1581 Vertical Tray Flame Test
  • UL 1666 Riser Flame Test
  • NFPA262, UL910 Steiner Tunnel Test

UP VW1 test on a single cable. This is the lowest grade test for assessing the fire resistant ability of a single cable. It is also similar to IEC 60332-1. It applies a flame (500W) to a single vertical cable sample and assess flame spread capacity (pass or fail criteria).

UL 1581 Vertical Tray Flame Test This test is similar to the IEC60332- part 3 test for group of cables (Figure 9 – UL 1581 Vertical Tray Flame Test (CM rating))

The flame load is a 30kW burner with the vertical samples free standing (compared to IEC60332-3 which is installed against a wall). Optional smoke density measurements may also be made.

UL 1666 Riser Flame Test
This test address the need to assess fire performance for cables grouped in risers. In UL1666, cables are mounted in a vertical tray arrangement within a 19ft high concrete shaft divided into two compartments at the 12 ft level and with 1ft by 2ft opening between compartments (to mimic a cable riser). The ignition source is a gas flame of 155kW which is left to burn for 30 minutes. Cables pass the test if no "flame" appear at the top of the bottom compartment during the test. Char length and smoke obscuration, mass loss or heat release may (or may not) be measured. Results are based on flame height
Figure 10 – UL 1666 Riser Flame Test (CMR Rating)

150kW burner tested for 30 mins. for cables grouped on vertical tray in a riser shaft 19' high with bottom compartment 12' high. Criteria for passing test is the absence of flame at the bottom of top compartment during fire test.

NFPA262 or UL910 Steiner Tunnel Test
is most the stringent test for plenum cables. Test samples of cables grouped are loaded into a horizontal tunnel 25ft long by 1 ft wide (Steiner Tunnel). A gas flame of about 88kW is applied for 20 minutes under a 240 ft/min air flow rate. Flame spread distance along the cables (from flame origin) and smoke optical density at the exhaust duct of the tunnel are measured. Cables are certified acceptable when flame spread is less than 5ft from flame origin and optical smoke density do not exceed 0.5 peak and 0.15 average.
Figure 11 – UL910 or NFPA262, Steiner Tunnel

Cables certified under 'Steiner Tunnel' test are said to be fire resistant with low smoke characteristics and are suitable for use in plenums (space where services pipes and ducts are routed e.g. space above false ceiling).

Hierarchy of Fire Tests

A hierarchy of fire test as illustrated in Figure 4 above shows the fire performance rating rank by fire test.
Figure 12 – Hierarchy of Fire Performance Tests

Note: BRE/FRS refers to the "Building Research Establishment/ Fire Research Station" at Bedford, England who set up full scale or scaled test rigs.

Next --> Figures; of Fire Tests

(1) Abstract and Introduction
(2) Overview of BS5839-1 and NFPA72
(3) Circuit Design and Survivability
(4) Appendix B – Circuits By Class and Style NFPA 72-2002
(5) Power Supply, Emergency Supply, Fail Safe Supply
(6) Cable Types, Fire Tests of Cables and Installation Practice
(7) Fire Test -Figure2 3 t0 12
(8) Conclusion & Trends

Are You Designing Fire Alarm System In Accordance with the Code – 4

Power Supply, Emergency Supply, Fail Safe Supply

Principles of reliability of power supply and similarity between both codes. Power supply for fire protection systems under both codes contain similar principles of ensuring reliability of power supplies. Primary supply source which are unreliable should not affect the operation during normal operation and response during fire conditions. Both codes advocate the backing up of primary (or main source) power supply with a standby supply with or without generator back-up.

Power supply prescribed in BS5839-1 can be summarised as follows:

Primary power connection:

~~Cables/apparatus directly connected to a public or private distribution supply should be in accordance with IEE Wiring Regulations (BS7671).

~~ Connection to the mains supply should be via an isolating protective device (e.g. isolating switch-fuse) reserved solely for the purpose. Isolating device should be suitably labelled with warning (in red) and may be enclosed in secure box to prevent unauthorised access.

~~The design of the system should ensure that residual current devices (RCD) are not necessary. In cases where RCD is unavoidable, interruption of the general building supply in response to a fault should not result in interruption of the fire alarm supply.

~~Continuity of supply to fire alarm system should be ensured.

~~Switching off supply due to reasons of maintenance, emergency, energy savings etc should not affect power to (except in unoccupied premises with a simple manual system).

~~In distributed power supply system, failure or disconnection of the supply to any individual unit should be indicated at the main indicator panel as a fault. Any switch that can disconnect the power supplies to all or part of the system should be suitably labelled with warning and coloured red.

Types of power supply

~~Normal supply should be derived from the public supply system, transformed or modified Where no public supply system is available, privately generated power may be used.

~~Standby Supplies comprise secondary batteries or secondary batteries augmented with standby generators.

Maximum alarm loads is defined as the maximum load imposed by the alarm system under fire conditions. It include the power required to operate sounders, detectors, fault warning and illumination of monitoring devices and all ancillary services powered by the fire alarm system.

Standby Supply Generally standby supply are as follows:

~~Comprises of a rechargeable battery and automatic charger. The battery should have an expected life of 4 years. Car batteries are not to be used.

~~The batteries should be labelled with their date of installation. Battery should charge up from its final voltage in 24Hrs.

~~For category M and L systems the battery should be able to support the system for 24hrs and then sound the alarm for 30 mins. If a back up generator is used the battery should be able to support the system for 6hrs and then sound the alarm for 30 mins.

~~For category P the 24 hrs plus half an hour ring applies a) providing the building is 'supervised' (staff monitoring at 6 hours interval) or b) power failures are automatically notified to a remote station for response from supervisor.

~~For category P the battery should support the system for 24 hrs longer than the building is unoccupied up to 72 hrs whichever is the less, plus half an hour ringing whatever applies. If the building is ever unoccupied for longer than the standby battery time and there is facility for remote transmission then the power fault should be remotely transmitted.

Power supply in NFPA72
can be summarised in the following terms:

Power source:

~~Fire alarm system shall be provided with at least two independent source of power supplies; one primary and the other secondary (standby).

~~Exceptions to above; when the primary source is supplied by a dedicated branch circuit of an emergency supply system or a legally required or optional standby system.

Notes: NFPA70 or the 'National Electrical Code' (NEC); Articles 700 defines Emergency Supply System as essentially for emergency loads (load during emergency condition); Article 701 Legally Required Standby System is a subset of Article 700 system but restricted for legally required load (communications, legal utilities etc), and Article 702 defines Optional Standby System for loads which may contribute to life safety but are not within the purview of legally sanctioned standby loads.

Primary Supply

~~Primary supply shall have high degree of reliability and may be either i) a light & power service (i.e. normal mains supply), or ii) an engine-generator set provided such generator are fully supervised by trained operator.

~~Connections to 'light & power' service shall be from dedicated branch circuits. Circuit should be mechanically protected. Circuit disconnector should red-marked, prominently labelled and accessible only to authorised personnel.

~~Overcurrent protection devices to protect against short circuit in ungrounded conductor shall be provided.

Notes: Overcurrent protection against short circuit protection will normally perrtain to fine-protection class fuses (IEC standard). Depending on the location of the circuit and prospective short circuit current, Miniature Circuit Breaker (MCB) may not be capable of interrupting short circuits above 6kA. However, this condition principally relates to the North American centre-tap 110/220V system which may produce higher short circuit currents compared to the IEC defined TN-S system which would be the norm for final circuit for power outlets in Malaysia.

Secondary Supply The secondary supply shall automatically supply energy to the system within 30 seconds, without loss of signal, whenever the primary supply system fails.

The secondary supply system shall have sufficient capacity to operate:

  • 24 hours the complete system under maximum quiescent conditions;
  • and then be capable of operating 15 minutes of full evacuation alarm operation at maximum connected load.

Secondary supply for emergency voice alarm communication system shall similarly operate 24 hours under quiescent conditions and shall be capable of operating the system for 2 hours during emergency conditions.

The secondary supply may consist of

  • storage battery system, or
  • standby generator system augmented with storage battery of 4 hours capacity (duration to power the fire alarm system).

Continuity of Power Supply
pertains to all cases of power transfer between primary and secondary source and can also be taken to cover power source connected from emergency or standby system. Continuity of supply must be maintained as follows:

~~power transfer must be automatic and generator must start up within 30 seconds;

~~standby batteries shall be maintain continuity of supply and to provide 15 mins. of power supply to the alarm system and to computer UPS forming part of the fire alarm system.

Next à Cable Types

(1) Abstract and Introduction

(2) Overview of BS5839-1 and NFPA72

(3) Circuit Design and Survivability

(4) Appendix B – Circuits By Class and Style NFPA 72-2002

(5) Power Supply, Emergency Supply, Fail Safe Supply

(6) Cable Types, Fire Tests of Cables and Installation Practice

(7) Fire Test -Figure2 3 t0 12

(8) Conclusion & Trends

Are You Designing Fire Alarm System In Accordance with the Code – 3 Appendix B

Appendix B -Circuit By Class and Style, NFPA 2002

Are You Designing Fire Alarm System In Accordance with the Code – 3?

Circuit Design and Survivability
The integrity or survivability of fire alarm circuits.
As noted in the previous section, the need to maintain circuit integrity (BS5839-1) or circuit survivability (NFPA72) shares commonality in concept and ideas which are receiving increasing attention in both codes. The idea of circuit integrity or survivability arises from the understanding that fire can develop before it is registered by the detectors and/or alarm raised. The interval between the start of a fire and its putative detection may very well damage components of the alarm system thereby increasing the response time to its discovery and eventual intervention by fire officers. Such scenario is increasingly a possibility due to the complexity of buildings and its internal space planning.

Circuit integrity in BS5839-1 is defined in prescriptive terms which can be summarised as follows:
Circuits containing detectors
~A fault, or faults, in one zone cannot prevent the operation of the system in other zones of the building.
~A single fault should not remove protection from an area greater than that allowed for a single zone (which has a maximum area of 2,000m²).
~Two simultaneous faults should not remove protection from an area greater than 10,000 m².
~Removal of detectors or call point from the circuit should cause indication of fault signals for immediate intervention by officers.
~Detectors designed to be removable from their bases should not affect the operation of manual call points.
~Malicious removal may be considered by the inclusion of lockable device with special tools for removal of detectors.
~The system should be designed to minimise disruption during maintenance and testing. It is desirable that provision be made allowing individual detectors to be tested without the need to sound an alarm or to disable the particular circuit.
~Isolation of all detectors or call points in single zone system is permissible but facility retained for allowing activation of general alarm from the control panel.
~Provision for isolation of detectors or call points for maintenance or testing should be such as to allow the operation of alarm sounders in response to the operation of detectors or call points that have not been isolated.
Circuits containing fire alarm sounders
~If alarm sounders are connected to the same wiring as detectors, then no alarm sounder should be affected by the removal of any detector.
~Any sounder that is necessary in order to reach the recommended audibility levels (65dB or 5dB above ambient noise level or 75dB in case of premises with sleeping resident) should only be removable or electrically disconnected from the sounder circuit by the use of a special tool and the disconnection should generate a fault warning at the control and indicating equipment.
Devices which are connected in a ring (usually though not always for addressable systems)
~Provided that the devices can receive or send signals in either direction, they will continue to operate even with a single circuit or high series resistance in the ring. Such faults should be indicated at the control and indicating equipment within 60 min of their occurrence.
~Short circuit on simple ring circuit (which cannot offer protection against such fault), should be indicated, without giving a false alarm of fire, within 100 s.
~Where sounders are used in simple ring circuits, the distribution wiring to each sounder circuit should be protected against overload due to short circuit by a fuse or similar device.
~Short circuit isolating devices are recommended for protection against cable faults in ring systems, where such device will isolate short circuit to sections of the circuit without affecting the whole circuit.
In most case, implementing measures to comply with the above requirement involve physical configuration of hard wiring and/or hardware which have to be addressed during design stage. Some examples are as follows:
~~Physical segregation of circuits between zone.
~~All sounders to be physically hardwired separately from detector circuits.
~~In case of ring circuit (usually though not limited to addressable system circuited in a loop), the above two measures may have to be adopted (i.e. physical segregation of circuits) despite the ability of addressable circuits to accommodate individual devices in a loop.
~~Alternatively short circuit isolating devices (either inbuilt into initiating or notification devices or installed discretely onto segments of the ring) may be used to demarcate segment of the ring to comply with the above requirements.
~~In a ring circuit, the start and return leg of the loop are physically routed separately.
~~Physical configuration of control panel, devices and circuits allow for fault indication in case of short circuit and removal of devices from the circuit (similar to class A and B circuit under NFPA72 and illustrated in Figures 1 and 2 below).
Class and style of circuit in NFPA72 as defined carries similar notion of circuit integrity as in BS5839-1.
Class Circuits are designated class A or B depending on its capability to transmit alarm and trouble signals during non-simultaneous single circuit fault conditions:
~Class A circuits are capable of transmitting an alarm signal during a single open or a non-simultaneous single ground fault.
~Class B circuits are incapable of transmitting an alarm beyond the location of the fault conditions specified for class A.
Style for initiating devices, notification appliances and signalling line circuits describe requirements in addition to the requirements for Class A and B circuits. Styles are designated for the various circuits depending on its ability to meet alarm and trouble performance during a single open, single ground, wire-to-wire short and loss-of-carrier fault condition.
~Initiating device circuit shall be Style A, B, C, D or E (table 1 in Appendix B);
~Notification appliance circuit shall be Style W, X, Y or Z (table 2 in Appendix B).
~Signalling line circuit shall be Style 0.5, 1, 2, 3, 3.5, 4, 4.5, 5, 6 or 7 (table 3 in Appendix B).
Further conditions on circuits prescribed can be summarised as follows:
~All styles of Class A circuits (except wireless circuits) shall be installed with outgoing and incoming conductors physically routed separately.
~Exceptions to above (separation of incoming and outgoing) are when:
distance of loop do not exceed 10ft (3m);

vertically run conductors are enclosed in 2-hour rated cable assembly or enclosure;
~~ in looped conduit/raceway single drop to individual devices is permitted;
~~ in looped conduit/raceway single conduit or raceway drops or tap-outs to multiple devices within a single room not exceeding 1,000ft² (92.9m²) in area shall be permitted.
Tables in Appendix B illustrates implementation of circuit by style.

Next Appendix B
(1) Abstract and Introduction
(2) Overview of BS5839-1 and NFPA72
(3) Circuit Design and Survivability
(4) Appendix B – Circuits By Class and Style NFPA 72-2002
(5) Power Supply, Emergency Supply, Fail Safe Supply
(6) Cable Types, Fire Tests of Cables and Installation Practice

(7) Fire Test -Figure2 3 t0 12
(8) Conclusion & Trends