1.0 General
1.1 The transient voltage surge suppression system shall be designed to protect all AC power circuits and connected load equipment from the destructive, damaging or disruptive effects of transient voltage activity induced by lightning, normal electricity supply load switching activity or grid faults. Protection must also be provided against internally generated transient voltage activity from the normal operation of connected load equipment, and capacitive and inductive load switching.

1.2 A surge protective device (SPD) shall be provided for each building incoming AC power supply and all supplies entering or leaving the building.

1.3 Sub-distribution, final circuit distribution boards and individual load equipment supplies shall be protected as determined by the location, sensitivity and criticality of the connected load equipment. All sensitive or critical load equipment shall have at least two tiers of suppression.

2.0 Products
2.1 Equipment shall be manufactured by Eaton MEM Circuit Protection & Control/ Innovative Technology Inc., or equal and approved.

2.2 Main panels, sub-distribution panels and supplies feeding electro-mechanical services shall be protected by a surge protective device with Threshold Suppression Network® protection.

2.3 Sensitive and critical electronic equipment (for example, PLC control systems, building management systems, data communications equipment, I.T. suites etc) shall be protected by a surge protective device with Threshold Suppression Network® and multi-stage hybrid Active Tracking Network® , which follows the AC sine wave to provide the close protection required against switching generated ring-wave and high energy impulse generated transients, responding immediately at any phase angle or polarity.

2.4 The surge protective device shall protect all possible modes. (Line to neutral x 3, line to line x 3, line to earth x 3 and neutral to earth, for a three phase star connected system) Sensitive and critical electronic equipment shall utilise dedicated components to protect each of the 10 modes.

2.5 Product selection information is available on the MEM TVSS UK Panel Model Application and Selection Guide.

2.6 All surge protective devices shall carry a manufacturer's 20 year limited free replacement warranty (10 year limited free replacement warranty on Memshield 2, XT40 and series wired devices). Warranties carrying exclusion clauses for 'acts of nature', which typically include the threat of lightning, to which the surge protective device is likely to be exposed, shall NOT be acceptable.

2.7 All suppression components shall be encapsulated in an electrochemical compound to extend component life and eliminate adverse environmental conditions such as water/chemical spray or vibration).

2.8 Visual suppressor status indication shall be provided by means of LED illumination. One LED per phase is required.

2.9 Remote suppressor status indication shall be provided by means of normally open/normally closed Form C dry relay contacts. Notification shall be achieved by use of an ARM-003 Alarm Remote Module unit. (Not applicable to Memshield 2, XT40 and series wired devices.)

2.10 The surge protective device enclosure shall be IP66 rated, of metal construction and include an internally threaded conduit fitting. No separate enclosure shall be required for distribution board mounted devices.
(Not applicable to Memshield 2 and individual load equipment models).

2.11 The option of SMART diagnostics shall provide comprehensive system monitoring functions on an LED and LCD display panel providing real time audible and visual reporting of unit status for phase loss, protection loss, transient event (surge) counter, and non-volatile stored cumulative transient event history. (Not applicable to 40kA, Memshield 2 and series wired units). The diagnostics shall carry a manufacturer's independent 10 year limited free replacement warranty.

3.0 Product Performance and Standards Compliance
3.1 All surge protective devices shall be designed, manufactured and tested in accordance with ANSI/IEEE C62.41-1991, Recommended Practice on Surge Voltages in Low Voltage AC Power Circuits.

3.2 Measured limiting voltage test data shall be provided for all combinations of conductors, (Line to neutral, line to line, line to earth and neutral to earth). Data is required for tests with the A1 Ring Wave (100Khz Ring Wave 2,000V, 67A at 180° phase angle), the B3/C1 Combination Wave (6,000V 1.2/50µS, 3000A 8/20µS at 90° phase angle), and the C3 Impulse Wave (20,000V 1.2/50µS, 10,000A 8/20µS at 90° phase angle). Test data shall be provided at a measured 152.4mm (6 inch) lead length from the SPD enclosure, simulating as-installed conditions. Test data at a module, or at the terminals of the device shall NOT be acceptable.

3.3 All tests shall be carried out in accordance with ANSI/IEEE C62.45-1992, IEEE Guide on Surge Testing for Equipment Connected to Low Voltage AC Power Circuits.

3.4 All surge protective devices shall be tested in accordance with Underwriters Laboratories UL 1449 Second Edition Standard for Safety Ð Transient Voltage Surge Suppressors, Effective 1998. All devices shall bear the Suppressed Voltage Rating issued by UL for all protected modes. This shall not exceed 800V line to neutral, 1500V line to line, 800V line to earth and 800V neutral to earth.

3.5 All surge protective devices shall be tested in accordance with Underwriters Laboratories UL 1283 Standard for Safety Ð Electromagnetic Interference Filters, Effective 1993. Surge protective devices offering enhanced or extended range EMI/RFI filtering and/or suppression by reference to NEMA LS-1 elements on MIL-Std. 220A, or through compliance with MIL-Std 220A shall NOT be acceptable.

3.6 The surge protective device manufacturer shall operate a quality management system in accordance with BSEN ISO 9001:1994. The certification body shall be accredited by the UK National Accreditation Council for Certification Bodies.

NOTES: British Standard BS6651 (Appendix 'C') is commensurate with ANSI/IEEE C62.41-1991 and C62.45-1992.

4.0 Installation
4.1 The surge protective device shall be installed such that all conductors are kept as short and straight as practically possible. Where installation allows, this shall be 150mm or less. The conductors shall be bound together along their length. No extension to the manufacturer's pre-installed conductors shall be permitted, and any excess conductor length is to be removed. The conductors shall not be coiled in any installation. No sharp bends shall be placed along the length of the suppressor conductors.

4.2 The surge protective devices shall be installed in accordance with the manufacturer's installation instructions, or shall not be warranted.

4.3 The surge protective device shall be connected in parallel to AC power distribution boards, and supplied from a protective device of appropriate current rating and short-circuit withstand rating for the installed location. This may be BS88 fuses, a moulded case circuit breaker conforming to BSEN 60-947-2, or a miniature circuit breaker conforming to BSEN 60-898. A single phase or three phase device shall be utilised, as appropriate.

4.4 Series wired devices may be utilised to protect individual, single phase items of load equipment. The supply shall be protected by a device of appropriate current rating and short-circuit withstand rating for the installed location.

4.5 Where surge protective devices are mounted within new switchboards they shall be installed by the switchboard manufacturer, as part of the manufacturing process. The protective device feeding the SPD shall be mounted directly adjacent to that SPD, and connected to the main switchboard busbar by solid copper links.

4.6 Where surge protective devices are mounted within a switchboard or distribution board, the visual status indication shall remain visible by means of a clear Perspex cover. If this is not practical, remote status indication must be utilised to provide unit status information on the front of the board enclosure.

4.7 The surge protective device shall be securely mounted by means of the internally threaded conduit fitting and multi-point mounting feet.

4.8 The metal case of surge protective devices protecting distribution boards utilising an isolated earth (clean earth) bar, must be electrically isolated from the case/housing of any such board, and the SPD earth conductor connected to the isolated earth (clean earth) bar on the distribution board.