EN 54-17 Fire detection and fire alarm systems – Part 17: Short-circuit isolators

EN 54 series is given in Annex A of EN 54-1:1996.
EN 54 “Fire detection and fire alarm systems” consists of the following parts: Part 1: Introduction
Part 2: Control and indicating equipment Part 3: Fire alarm devices – Sounders Part 4: Power supply equipment Part 5: Heat detectors – Point detectors
Part 7: Smoke detectors – Point detectors using scattered light, transmitted light or ionization Part 10: Flame detectors – Point detectors Part 11: Manual call points
Part 12: Smoke detectors – Line detectors using an optical light beam Part 13: Compatibility assessment of system components
Part 14: Guidelines for planning, design, installation, commissioning, use and maintenance
Part 15: Point type multi-sensor fire detectors
Part 16: Voice alarm control and indicating equipment
Part 17: Short-circuit isolators
Part 18: Input/output devices Part 20: Aspirating smoke detectors
Part 21: Alarm transmission and fault warning routing equipment
Part 22: Line-type heat detectors
Part 23: Fire alarm devices – Visual alarms
Part 24: Components of voice alarm systems – Loudspeakers
Part 25: Components using radio links and system requirements

1 Scope
This European Standard specifies requirements, test methods and performance criteria for short- circuit isolators, for use in fire detection and fire alarm systems for buildings (see EN 54-1).
Means of isolation or protection incorporated within control and indicating equipment (item B in Figure 1 of EN 54-1:1996) are not covered by this European Standard.

2 Normative references
The following referenced documents are indispensable for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 54-1:1996, Fire detection and fire alarm systems — Part 1: Introduction
EN 50130-4:1995, Alarm systems — Part 4: Electromagnetic compatibility – Product family standard: Immunity requirements for components of fire, intruder and social alarm systems
EN 60068-1, Environmental testing — Part 1: General and guidance (IEC 60068-1:1988 + Corrigendum 1988 + A1:1992)
EN 60068-2-1, Environmental testing — Part 2: Tests — Tests A: Cold (IEC 60068-2-1:1990)
EN 60068-2-2, Basic environmental testing procedures — Part 2: Tests — Tests B: Dry heat (IEC 60068-2-2:1974 + IEC 60068-2-2A:1976)
EN 60068-2-6, Environmental testing — Part 2: Tests — Test Fc: Vibration (sinusoidal) (IEC 60068-2¬6:1995 + Corrigendum 1995)
EN 60068-2-27, Basic environmental testing procedures — Part 2: Tests — Test Ea and guidance: Shock (IEC 60068-2-27:1987)
EN 60068-2-30, Environmental testing — Part 2: Tests — Test Db and guidance: Damp heat, cyclic (12 + 12 hour cycle) (IEC 60068-2-30:1980 + A1:1985)
EN 60068-2-42, Environmental testing — Part 2-42: Tests — Test Kc: Sulphur dioxide test for contacts and connections (IEC 60068-2-42:2003)
EN 60068-2-78, Environmental testing — Part 2-78: Tests — Test Cab: Damp heat, steady state (IEC 60068-2-78:2001)
ISO 209-1:1989, Wrought aluminium and aluminium alloys — Chemical composition and forms of products — Part 1: Chemical composition

3 Terms and definitions
For the purposes of this European Standard, the terms and definitions given in EN 54-1:1996 and the following apply.
3.1
short-circuit isolator
device, which may be connected into a transmission path of a fire detection and fire alarm system, to limit the consequences of low parallel resistance faults between the lines of this transmission path
NOTE A short circuit isolating device may be a physically separate device or it may be incorporated into another device apart from the control and indicating equipment (e.g. integrated into a smoke detector or detector base).
3.2
closed condition
condition of the short-circuit isolator which allows the normal signals and supply currents to pass through the short-circuit isolator (i.e. the correct condition for the short-circuit isolator when there is no short circuit)
3.3
open condition
condition of the short-circuit isolator which prevents the passage of short circuit currents through the short-circuit isolator. (i.e. the correct condition for the short-circuit isolator when it is protecting part of a circuit from the effects of a short circuit)
4 Requirements
4.1 Compliance
In order to comply with this European Standard the short-circuit isolator shall meet the requirements of this clause, which shall be verified by visual inspection or engineering assessment, shall be tested as described in Clause 5 and shall meet the requirements of the tests. However, for short circuit isolating devices which are integrated into other devices already covered by an existing European Standard (EN), the environmental conditioning shall be performed in accordance with that EN.
4.2 Integral status indication
If the short-circuit isolator incorporates an integral visual indication of its status, then this indication shall not be red.
4.3 Connection of ancillary devices
Where the short-circuit isolator provides for connections to ancillary devices (e.g. remote indicators), open- or short-circuit failures of these connections shall not prevent the correct operation of the short- circuit isolator.
4.4 Monitoring of detachable short-circuit isolators
If a short circuit isolating device is detachable (i.e. it is attached to a mounting base), then a means shall be provided for a remote monitoring system (e.g. the control and indicating equipment) to detect the removal of the device from the base, in order to give a fault signal.
4.5 Manufacturer’s adjustments
It shall not be possible to change the manufacturer’s settings except by special means (e.g. the use of a special code or tool) or by breaking or removing a seal.
4.6 On-site adjustments
If there is provision for on-site adjustment of the short-circuit isolator, then for each setting the short- circuit isolator shall comply with the requirements of this European Standard. Access to the means of adjustment shall only be possible by the use of a code or special tool.
4.7 Marking
Each short-circuit isolator shall be clearly marked with the following information:
The marking shall be visible during installation of the short-circuit isolator and shall be accessible during maintenance.
The markings shall not be placed on screws or other easily removable parts.
NOTE Where ZA.3 covers the same information as required by this subclause, the requirements of this subclause are met.
4.8 Data
Short-circuit isolators shall either be supplied with sufficient technical, installation and maintenance data to enable their correct installation and operation or, if all of these data are not supplied with each isolator, reference to the appropriate data sheet shall be given on, or with, each short-circuit isolator.
At least the following data are required to conduct the tests specified in this European Standard:
4.9 Additional requirements for software controlled short-circuit isolators
4.9.1 General
For short-circuit isolators which rely on software control in order to fulfil the requirements of this European Standard, the requirements of 4.9.2, 4.9.3 and 4.9.4 shall be met.
,4.9.2 Software documentation
4.9.2.1 The manufacturer shall submit documentation, which gives an overview of the software design. This documentation shall be in sufficient detail for the design to be inspected for compliance with this European Standard and shall include at least the following:
,— a functional description of the main program flow (e.g. as a flow diagram or structogram) – including:
4.9.2.2 The manufacturer shall have available detailed design documentation, which only needs to be provided if required by the testing authority. It shall comprise at least the following:
a) an overview of the whole configuration of the device, including all software and hardware components;
b) a description of each module of the program, containing at least:
1) the name of the module;
2) a description of the tasks performed;
3) a description of the interfaces, including the type of data transfer, the valid data range and the checking for valid data;
c) full source code listings, as hard copy or in machine-readable form (e.g. ASCII- code), including all global and local variables, constants and labels used, and sufficient comment for the program flow to be recognized;
d) details of any software tools used in the design and implementation phase (e.g. CASE-tools, compilers).
4.9.3 Software design
In order to ensure the reliability of the short-circuit isolator, the following requirements for software design shall apply:
a) the software shall have a modular structure;
b) the design of the interfaces for manually and automatically generated data shall not permit invalid data to cause error in the program operation;
c) the software shall be designed to avoid the occurrence of deadlock of the program flow.
4.9.4 The storage of programs and data
The program necessary to comply with this European Standard and any preset data, such as manufacturer’s settings, shall be held in non-volatile memory. Writing to areas of memory containing this program and data shall only be possible by the use of some special tool or code and shall not be possible during normal operation of the short-circuit isolator.
Site-specific data shall be held in memory which will retain data for at least two weeks without external power to the short-circuit isolator, unless provision is made for the automatic renewal of such data, following loss of power, within 1 h of power being restored.
5 Tests 5.1 General
5.1.1 Atmospheric conditions for tests
Unless otherwise stated in a test procedure, the testing shall be carried out after the test specimen has been allowed to stabilize in the standard atmospheric conditions for testing as described in EN 60068-1 as follows:
NOTE If variations in these parameters have a significant effect on a measurement, then such variations should be kept to a minimum during a series of measurements carried out as part of one test on one specimen.
5.1.2 Operating conditions for tests
If a test method requires a specimen to be operational, then the specimen shall be connected to suitable supply and monitoring equipment with characteristics as required by the manufacturer’s data. Unless otherwise specified in the test method, the supply parameters applied to the specimen shall be set within the manufacturer’s specified range(s) and shall remain substantially constant throughout the tests. The value chosen for each parameter shall normally be the nominal value, or the mean of the specified range. The short-circuit isolator shall be set to the closed condition and the supply and monitoring equipment shall be able to detect if the isolator changes to the open condition.
5.1.3 Mounting arrangements
The specimen shall be mounted by its normal means of attachment in accordance with the manufacturer’s instructions. If these instructions describe more than one method of mounting then the method considered to be most unfavourable shall be chosen for each test.
5.1.4 Tolerances
Unless otherwise stated, the tolerances for the environmental test parameters shall be as given in the basic reference standards for the test (e.g. the relevant part of EN 60068).
If a requirement or test procedure does not specify a tolerance or deviation limits, then deviation limits of ± 5 % shall be applied.
5.1.5 Functional test
5.1.5.1 Object
To confirm the correct operation of the short-circuit isolators, in accordance with the manufacturer’s specification, and to verify their stability after and, where required, during the environmental and EMC tests.
5.1.5.2 Test procedure
The functional test shall verify that the short-circuit isolator operates within the manufacturer’s specification. The functional test shall verify at least the following for each side of the short-circuit isolator:
5.1.6 Provision for tests
The following shall be provided for testing compliance with this European Standard:
a) fourteen specimens are required to conduct the tests as indicated in the test schedule, see 5.1.7. These specimens shall be numbered 1 to 14 arbitrarily;
b) the technical data required in 4.8 and 4.9.
The specimens submitted shall be representative of the manufacturer’s normal production with regard to their construction and calibration.
5.1.7 Test schedule
The specimens shall be tested according to the following test schedule (see Table 1).
5.2 Reproducibility
5.2.1 Object
To show that each specimen meets the manufacturer’s specifications.
5.2.2 Test procedure
The functional test described in 5.1.5 shall be conducted on each specimen.
5.2.3 Requirements
Each specimen shall function correctly within the manufacturer’s specification.
5.3 Variation in supply voltage
5.3.1 Object
To show that the short-circuit isolator meets the manufacturer’s specifications for the specified range of supply voltage.
5.3.2 Test procedure
The functional test described in 5.1.5 shall be conducted at the upper and lower limits of the supply voltage range specified by the manufacturer.
NOTE In the examples given in Annex A, this would mean replacing V nom by V max and V min.
5.3.3 Requirements
The specimen shall function correctly within the manufacturer’s specification.
5.4 Dry heat (operational)
5.4.1 Object
To demonstrate the ability of the short-circuit isolator to function correctly at high ambient temperatures appropriate to the anticipated service environment.
5.4.2 Test procedure
5.4.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-2, Test Bb and as indicated below.
5.4.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 and shall be connected to supply and monitoring equipment as described in 5.1.2.
5.4.2.3 Conditioning
The following conditioning shall be applied:
5.4.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any change from the closed condition.
During the last hour of the conditioning period, the functional test as described in 5.1.5 shall be conducted.
5.4.2.5 Final measurements
After a recovery period of at least 1 h at the standard laboratory conditions, the functional test as described in 5.1.5 shall be conducted.
5.4.3 Requirements
The specimen shall remain in the closed condition during the conditioning period except when required to change during the functional test.
The specimen shall function correctly within the manufacturer’s specification during both of the functional tests.
5.5 Cold (operational)
5.5.1 Object
To demonstrate the ability of the short-circuit isolator to function correctly at low ambient temperatures appropriate to the anticipated service environment.
5.5.2 Test procedure
5.5.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-1, Test Ab and as described below.
5.5.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 and shall be connected to supply and monitoring equipment as described in 5.1.2.
5.5.2.3 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any change from the closed condition.
During the last hour of the conditioning period, the functional test as described in 5.1.5 shall be conducted.
5.5.2.4 Final measurements
After a recovery period of at least 1 h at the standard laboratory conditions, the functional test as described in 5.1.5 shall be conducted.
5.5.3 Requirements
The specimen shall remain in the closed condition during the conditioning period except when required to change during the functional test.
The specimen shall function correctly within the manufacturer’s specification during both of the functional tests.
5.6 Damp heat, cyclic (operational)
5.6.1 Object
To demonstrate the ability of the short-circuit isolator to function correctly at high relative humidity (with condensation), which can occur for short periods in the anticipated service environment.
5.6.2 Test procedure
5.6.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-30, Test Db using the Variant 1 test cycle and controlled recovery conditions and as described below.
5.6.2.2 State of the specimen(s) during conditioning
The specimen shall be mounted as described in 5.1.3 and shall be connected to supply and monitoring equipment as described in 5.1.2.
5.6.2.3 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any change from the closed condition.
5.6.2.4 Final measurements
After the recovery period, the functional test as described in 5.1.5 shall be conducted.
5.6.3 Requirements
The specimen shall remain in the closed condition during the conditioning period.
The specimen shall function correctly within the manufacturer’s specification during the functional test.
5.7 Damp heat, steady state (endurance)
5.7.1 Object
To demonstrate the ability of the short-circuit isolator to withstand the long-term effects of humidity in the service environment (e.g. changes in electrical properties of materials, chemical reactions involving moisture or galvanic corrosion).
5.7.2 Test procedure
5.7.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-78, Test Cab and as described below.
5.7.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 but shall not be supplied with power during the conditioning.
5.7.2.3 Conditioning
The following conditioning shall be applied: Temperature: (40 ± 2) °C
Relative humidity: (93 ± 3) % Duration: 21 days
5.7.2.4 Final measurements
After a recovery period of at least 1 h at the standard laboratory conditions, the functional test as described in 5.1.5 shall be conducted.
5.7.3 Requirements
The specimen shall function correctly within the manufacturer’s specification during the functional test.
5.8 Sulphur dioxide (SO2) corrosion (endurance)
5.8.1 Object
To demonstrate the ability of the short-circuit isolator to withstand the corrosive effects of sulphur dioxide as an atmospheric pollutant.
5.8.2 Test procedure 5.8.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-42, Test Kc, except that the conditioning shall be as described below.
5.8.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3. It shall not be supplied with power during the conditioning, but it shall have un-tinned copper wires, of the appropriate diameter, connected to sufficient terminals to allow the final measurement to be made, without making further connections to the specimen.
5.8.2.3 Conditioning
The following conditioning shall be applied: Temperature: (25 ± 2) °C
Relative humidity: (93 ± 3) % SO2 concentration: (25 ± 5) x 10-6 Duration: 21 days
5.8.2.4 Final measurements
Immediately after the conditioning, the specimen shall be subjected to a drying period of 16 h at (40 ± 2) °C, < 50 % RH, followed by a recovery period of at least 1 h at the standard laboratory conditions. After this, the functional test as described in 5.1.5 shall be conducted.
5.8.3 Requirements
The specimen shall function correctly within the manufacturer’s specification during the functional test.
5.9 Shock (operational)
5.9.1 Object
To demonstrate the immunity of the short-circuit isolator to mechanical shocks, which are likely to occur, albeit infrequently, in the anticipated service environment.
5.9.2 Test procedure
5.9.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-27, Test Ea, except that the conditioning shall be as described below.
5.9.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 to a rigid fixture, and shall be connected to its supply and monitoring equipment as described in 5.1.2.
5.9.2.3 Measurements during conditioning
The specimen shall be monitored during the conditioning period and for a further 2 min to detect any change from the closed condition.
5.9.2.4 Final measurements
After the conditioning and the further 2 min, the functional test as described in 5.1.5 shall be conducted.
5.9.3 Requirements
The specimen shall remain in the closed condition during the conditioning period and the additional 2 min.
The specimen shall function correctly within the manufacturer’s specification during the functional test. 5.10 Impact (operational)
5.10.1 Object
To demonstrate the immunity of the short-circuit isolator to mechanical impacts upon its surface, which it may sustain in the normal service environment, and which it can reasonably be expected to withstand.
5.10.2 Test procedure
5.10.2.1 Apparatus
The test apparatus shall consist of a swinging hammer incorporating a rectangular-section aluminium alloy head (Aluminium alloy AlCu4SiMg complying with ISO 209-1, solution treated and precipitation treated condition) with the plane impact face chamfered to an angle of 60° to the horizontal, when in the striking position (i.e. when the hammer shaft is vertical). The hammer head shall be (50 ± 2,5) mm high, (76 ± 3,8) mm wide and (80 ± 4) mm long at mid height as shown in Figure B.1. A suitable apparatus is described in Annex B.
5.10.2.2 State of the specimen during conditioning
The specimen shall be rigidly mounted to the apparatus by its normal mounting means and shall be positioned so that it is struck by the upper half of the impact face when the hammer is in the vertical position (i.e. when the hammerhead is moving horizontally). The azimuthal direction and position of impact, relative to the specimen shall be chosen as that most likely to impair the normal functioning of the specimen. The specimen shall be connected to its supply and monitoring equipment as described in 5.1.2.
5.10.2.3 Conditioning
The following conditioning shall be applied: Impact energy: (1,9 ± 0,1) J
Hammer velocity: (1,5 ± 0,13) m s-1 Number of impacts: 1
5.10.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period and for a further 2 min to detect any change from the closed condition.
5.10.2.5 Final measurements
After the conditioning and the further 2 min, the functional test as described in 5.1.5 shall be conducted.
5.10.3 Requirements
The specimen shall remain in the closed condition during the conditioning period and the additional 2 min.
The specimen shall function correctly within the manufacturer’s specification during the functional test.
5.11 Vibration, sinusoidal (operational)
5.11.1 Object
To demonstrate the immunity of the short-circuit isolator to vibration at levels considered appropriate to the normal service environment.
5.11.2 Test procedure
5.11.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-6, Test Fc and as described below.
5.11.2.2 State of the specimen during conditioning
The specimen shall be mounted on a rigid fixture as described in 5.1.3 and shall be connected to its supply and monitoring equipment as described in 5.1.2. The vibration shall be applied in each of three mutually perpendicular axes, in turn. The specimen shall be mounted so that one of the three axes is perpendicular to its normal mounting plane.
5.11.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any change from the closed condition.
5.11.2.5 Final measurements
After the conditioning, the functional test as described in 5.1.5 shall be conducted.
NOTE If the vibration operational and endurance tests are combined, the final measurements are made after the vibration endurance test and only need be made here if the operational test is conducted in isolation.
5.11.3 Requirements
The specimen shall remain in the closed condition during the conditioning period.
If the final measurement, as specified in 5.11.2.5, has been conducted, the specimen shall function correctly within the manufacturer’s specification during the functional test.
5.12 Vibration, sinusoidal (endurance)
5.12.1 Object
To demonstrate the ability of the short-circuit isolator to withstand the long-term effects of vibration at levels appropriate to the service environment.
5.12.2 Test procedure 5.12.2.1 Reference
The test apparatus and procedure shall be as described in EN 60068-2-6, Test Fc and as described below.
5.12.2.2 State of the specimen during conditioning
The specimen shall be mounted on a rigid fixture as described in 5.1.3, but shall not be supplied with power during conditioning. The vibration shall be applied in each of three mutually perpendicular axes, in turn. The specimen shall be mounted so that one of the three axes is perpendicular to its normal mounting axis.
NOTE The vibration operational and endurance tests may be combined such that the specimen is subjected to the operational test conditioning followed by the endurance test conditioning in one axis before changing to the next axis. Only one final measurement need be made.
5.12.2.3 Final measurements
After the conditioning, the functional test as described in 5.1.5 shall be conducted. 5.12.3 Requirements
The specimen shall function correctly within the manufacturer’s specification during the functional test. 5.13 Electromagnetic Compatibility (EMC), Immunity tests (operational)
5.13.1 Object
To demonstrate the immunity of the short-circuit isolator to electromagnetic interference.
5.13.2 Test procedure
5.13.2.1 Reference
The test apparatus and procedure shall be as described in EN 50130-4 and as described below.
5.13.2.2 State of the specimen(s) during conditioning
The specimen shall be mounted as described in 5.1.3 and shall be connected to supply and monitoring equipment as described in 5.1.2.
5.13.2.3 Conditioning
The following EMC immunity tests shall be carried out, as described in EN 50130-4:
5.13.2.4 Measurements during conditioning
During the conditioning the specimen shall be monitored to detect any change of state or faulty operation.
5.13.2.5 Final measurements
After the conditioning, the functional test as described in 5.1.5 shall be conducted. 5.13.3 Requirements
The specimen shall remain in the closed condition without any faulty operation during conditioning. The specimen shall function correctly within the manufacturer’s specification during the functional test.