SUN - UL 1008 - CSA C22.2 No. 178.1 - ANCE NMX-J-672
Effective May 31, 2017
Standard Information
Standard Number:
UL 1008 / CSA C22.2 No. 178.1 / ANCE NMX-J-672
Standard Name:
Transfer Switch Equipment
Standard Edition and Issue Date:
8th / 3rd /2nd Edition Issued December 22, 2014
Date of Previous Revisions to Standard:
7th / 2nd / 1st Edition Revised April 11, 2013
Effective Date of New/Revised Requirements
Effective Date (see Schedule below): May 31, 2017
Impact, Overview, Fees and Action Required
Impact Statement: A review of all Listing Reports is necessary to determine which products comply with new/revised requirements and which products will require re-evaluation. NOTE: Effective immediately, this revised standard will be exclusively used for evaluation of new products unless the Applicant requests in writing that current requirements be used along with their understanding that their listings will be withdrawn on Effective Date noted above, unless the product is found to comply with new/revised requirements.
Overview of Changes:Significant additions, changes and revisions to construction, marking and test requirements. Specific details of new/revised requirements are found in table below.
If the applicable requirements noted in the table are not described in your report(s), these requirements will need to be confirmed as met and added to your report(s) such as markings, instructions, test results, etc. (as required).
Fees: So that production of products bearing the Listing Mark will not be interrupted, a quote will be issued for the Applicant to work with their local Intertek Lab to determine the necessary test program, sampling requirement and needed construction details and/or updated marking/instruction details.
Client Action Required:
Information – To assist our Engineer with review of your Listing Reports, please submit technical information in response to the new/revised paragraphs noted in the attached or explain why these new/revised requirements do not apply to your product (s).
Current Listings Not Active? – Please immediately identify any current Listing Reports or products that are no longer active and should be removed from our records. We will do this at no charge as long as Intertek is notified in writing prior to the review of your reports.
Description of New/Revised Technical Requirements
| Clause | Verdict | Comment |
|---|---|---|
| Clause cell highlighted in yellow means was in both UL and CSA doc. | ||
| 1.1 | Info | New Scope increased to 1000V, and adding branch circuit emergency lighting transfer switches (BCELTS) (U.S. and Mexico only). |
| 1.2 | Info | The standard does not apply to transfer switches rated over 1000V. |
| 1.6 | Info | In Canada, automatic transfer switches built to the optional standby requirements of this standard are not permitted. In Mexico and the United States, this requirement does not apply. |
| 1.7 | Info | New Added requirements for enclosed inlets intended to facilitate connection of portable generators to transfer equipment. |
| 2.1.6 | Info | In Canada, general requirements applicable to this standard are given in the latest edition of Annex A1, Item 11. |
| 3.2 | Info | Class 1 ground-fault protection device – A device that does not incorporate means to prevent opening of the disconnecting means at high levels of fault current and is intended for use with (a) – (d) of this subclause. |
| 3.12 (o) | Info | New Added a definition for branch circuit emergency lighting transfer switches (BCELTS) (U.S. and Mexico only). |
| 3.13 | Info | Systems: a) Emergency systems – those systems legally required and classified as essential for safety to human life by municipal, state, provincial, or federal codes, or any governmental authority having jurisdiction. In Canada, emergency systems are identified as emergency power supplies. In Mexico and the United States, this requirement does not apply. b) Legally-required standby systems in Mexico and the United States – those systems legally required by municipal, state, or federal codes, or any governmental authority having jurisdiction, but not classified as essential for safety to human life. In Canada, this requirement does not apply. c) Optional standby systems in Mexico and the United States – those systems installed to provide an alternate source of power for structures for which a power outage could cause discomfort or interruption or damage to products or processes. In Canada, this requirement does not apply. |
| 4.2.3 | Other than as noted in 4.2.4 – 4.2.6, a switch shall not be marked with a short-circuit rating that exceeds the maximum short-circuit rating of any overcurrent device intended to be installed therein for that rating, or the remote main overcurrent protective device with which it is intended to be used for that rating, or any other component as covered by its marking or, for unmarked components, by the values in Table 6. In Canada, Table 6 is not applicable. | |
| 4.2.6 | The switch short-circuit current rating may exceed the component short-circuit current rating marked on the device or in accordance with Table 6, if the marked or assumed short-circuit rating of the component is adequate for the assumed available short-circuit current at the component location as covered in 6.4.5 and 6.4.6. In Canada, Table 6 is not applicable. | |
| 4.2.10 | New Added requirement that BCELTS are rated for control of lighting loads rated not greater than 20A (U.S. and Mexico only). | |
| 5.2.1.32 | In Mexico and the United States, a transfer switch investigated for use in emergency systems or legally-required standby systems shall be marked ″automatic transfer switch for emergency systems″. In Canada, a transfer switch investigated for use in emergency systems shall be marked ″automatic transfer switch″. | |
| 5.2.1.33 | New Added markings for transfer switches in optional standby power systems (U.S. and Mexico only). | |
| 5.2.1.34 | New Added marking requirements for equipment intended to be mounted in plenums (different markings in U.S. and Mexico and Canada). | |
| 5.2.1.35 | New Added markings for manual transfer switches (U.S. and Mexico only) (Revision of Clause 5.2.7.10 in C22.2 No. 178.1-12 which was for Canada only). | |
| 5.2.1.36 | New Added markings for manual or automatic transfer switches with manual means of operation (U.S. and Mexico only) (Revision of Clause 5.2.7.11 in C22.2 No. 178.1-12 which was for Canada only). | |
| 5.2.1.37 | For field installed bus connections, directions in the form of a permanent drawing or
removable tag shall be provided and shall include at least the following information: a) The recommended number and dimensions of bus bars intended for the connection; b) The intended area of the connection; c) The bolt pattern, if pre-drilled holes are provided; and d) The recommended tightening torques if hardware is provided. | |
| 5.2.7.10 | New Added marking requirements for enclosed inlets for cord connection of generators. | |
| 5.2.7.11 | UL 1008 TR2 New Added marking requirements for enclosed inlets used with a transfer switch. | |
| 6.3.1.10 | If the connection mentioned in 6.3.1.9 is solely by means of a screw, strap, or other
bonding device that can be readily removed and is not depended upon to perform a
mechanical function, the transfer switch shall: a) Comply with the requirement in Table 3 when the bonding device is removed, or b) In Mexico and the United States, be marked as described in 5.2.6.1.6. In Canada, this requirement does not apply. | |
| 6.3.1.21 | In Mexico and the United States, other than as noted in 6.3.1.22, when a neutral is
factory bonded to the ground bus or enclosure, all conductive parts connected to the
neutral shall comply with the following: a) The parts shall be insulated from the ground bus and enclosure, and b) The parts shall be provided with a minimum of 3.2 mm (1/8 inch) spacing through air and over-surface to the enclosure. In Canada, this requirement does not apply. | |
| 6.3.2.1 | In Mexico, clearances and creepage distances provided on printed-wiring board assemblies may be less than indicated in Table 3, but not less than 0.8 mm (1/32 inch) provided the board is coated or encapsulated and an investigation is conducted to determine the acceptability of the coating or encapsulation. The investigation shall include temperature and humidity conditioning, preceded and followed by dielectric voltage-withstand tests. Flammability tests shall also be conducted on the combination of the coating or encapsulation and the board. In the United States and Canada, clearances and creepage distances provided on printed-wiring board assemblies may be less than indicated in Table 3, provided that they comply with 6.3.2.2 – 6.3.2.7. | |
| 6.4.3 | Revised Added provision that polymeric material suitable for use at 600V are considered acceptable for use at 1000V. | |
| 6.4.4 | In Mexico and the United States, a component not marked with a short-circuit current rating shall be considered rated for use in a circuit having a maximum available fault current as shown in Table 6. In Canada, this requirement does not apply. | |
| 6.5.5 | The enclosure of a transfer switch may be provided with ventilating openings. Ventilation openings shall comply with the requirements in 6.5.6 – 6.5.23. In Mexico and the United States, transfer switches rated less than 400 A may not be provided with ventilating openings. | |
| 6.5.29 | New Added requirement that non-metallic enclosures in air handling spaces to meet UL 243. | |
| 6.5.30 | New Added components for which Clause 6.25.29 do not apply. | |
| 6.5.31 | New Added that metallic enclosures are acceptable for use in air handling spaces without investigation. | |
| 6.6.2 | In Mexico and the United States, a conduit hub in an enclosure shall be threaded and shall have a wall thickness before threading not less than that of the corresponding trade-size of rigid conduit. A conduit hub shall not depend upon friction alone to prevent its turning, and shall be capable of withstanding the specified torque applied to a short length of rigid conduit threaded into the hub in the intended manner, without turning in the enclosure and without stripping of any threads. The enclosure shall be securely (rigidly) mounted or supported. For the 21 (3/4 inch) and smaller trade sizes, the applied torque shall be 90 N·m (800 pound-inches); for the 27, 35, and 41 (1, 1-1/4, and 1-1/2 inch) trade sizes, 113 N·m (1000 pound-inches); and for the 53 (2 inch) and larger sizes, 181 N·m (1600 pound-inches). In Canada, this requirement does not apply. | |
| 6.6.3 | In Mexico and the United States, a tapped hole for the attachment of threaded rigid
conduit shall be provided with: a) An end-stop, or shall be so located that a standard bushing may be attached to the end of the conduit; and b) A tapered thread in equipment for outdoor use, if not provided with an end stop; and c) At least three full threads when tapped all the way through the wall of an enclosure, or with at least 3-1/2 full threads and a smooth, well-rounded inlet hole having a diameter approximately the same as the internal diameter of a standard bushing to provide protection for the conductors equivalent to that provided by such a bushing. In Canada, this requirement does not apply. | |
| 6.6.4 | In Canada, the requirements for connections for wiring systems are contained in Annex A1, Items 11 and 21. In Mexico and the United States, this requirement does not apply. | |
| 6.8.2 | In Mexico and the United States, materials may either have no HWI values or may have HWI values higher (worse) than those required by Table 9 if the materials comply with the end-product Abnormal Overload Test in accordance with Annex A1, Item 7. In Canada, this requirement does not apply. | |
| 6.8.3 | In Mexico and the United States, materials may either have no HAI values or may have HAI values higher (worse) than those required by Table 9 if the materials comply with the end-product Arc Resistance Test in accordance with Annex A1, Item 7. In Canada, this requirement does not apply. | |
| 6.8.5 | In Mexico and the United States, materials may either have no CTI values or may have CTI values higher (worse) than the CTI required by Table 9 if the materials comply with the end-product Arc Resistance Test in accordance with Annex A1, Item 7. In Canada, this requirement does not apply. | |
| 6.5.31 | New Added that metallic enclosures are acceptable for use in air handling spaces without investigation. | |
| 7.1.1 | In Mexico and the United States, a transfer switch with identical power-switching
mechanisms as found on an approved automatic transfer switch shall qualify as a
manual transfer switch (electrically operated and/or externally manually operated)
without additional testing. For the purpose of this requirement, identical power
switching mechanisms are defined as mechanisms that provide identical speed of
contact operation and sequencing times. In Canada, this requirement does not apply. | |
| 7.1.4 | In Mexico and the United States, in the case of a transfer switch limited to use on optional standby systems, the operating mechanism is allowed to disconnect both the normal and alternate supplies, regardless of supply availability, as long as this intentional neutral position is factory installed in the mechanism and this position can be reliably maintained. In Canada, this requirement does not apply. | |
| 7.1.6 | The operating mechanism of the normal and emergency contacts of an automatic transfer switch for use in emergency systems shall be electrically operated. Other than as noted in 7.1.7, the normal and emergency contacts of an automatic transfer switch intended for use in emergency systems shall be mechanically held in a closed position. | |
| 7.1.7 | New Added requirement that if a BCELTS is not mechanically held in normal state, it shall default to emergency state upon loss of normal power (U.S. and Mexico only). | |
| 7.1.28 | In Mexico and the United States, in a transfer switch limited to use on an optional standby system the control circuit may extend outside the enclosure if mis-operation of the circuit cannot result in asynchronous paralleling of the two sources. In Canada, this requirement does not apply. | |
| 7.1.34 | With respect to 7.1.33, for automatic transfer switches for use in emergency or
legally-required systems, the time delays must be capable of being set such that the
transfer is completed in 10 seconds or less. In Mexico and the United States, transfer
times are not specified for transfer switches for use in optional standby systems. Note: Local requirements can govern total system transfer time and could require transfer-switching times to be less than stated. | |
| 7.1.35 | In Mexico and the United States, with respect to 7.1.34, for automatic transfer switches for use in optional standby systems, devices may be included to permit the load to be disconnected from both sources of supply simultaneously, provided that the transfer is automatically completed once the device has functioned as intended. In Canada, this requirement does not apply. | |
| 9.1.1.1 | To determine whether an automatic transfer switch is in compliance with 7.1.6, the
device shall be mounted in its normal operating position. The device, with no load
connected, shall be operated as follows: a) The switch shall be electrically operated to close the normal supply contacts. After the contacts are closed, all voltage sources shall be disconnected. The normal source contact shall remain closed as determined by a continuity tester and b) The switch shall be electrically operated to close the emergency supply contacts. After the contacts are closed, all voltage sources shall be disconnected. The emergency source contact shall remain closed as determined by a continuity tester. | |
| 9.1.1.2 | New Added mounting requirements for BCELTS (U.S. and Mexico only). | |
| 9.5.1 | To determine whether an automatic transfer switch complies with the requirements in
7.1.1 – 7.1.26, the switch shall be mounted in the intended manner and the normal
and alternate supply terminals shall be connected to separate circuits of voltage and
frequency in accordance with Table 15. The switch with no load connected shall be
caused to operate by the following means: a) Test switch, and b) Interrupting and then restoring, in turn, each conductor of the normal supply. | |
| 9.6.1 | To determine whether an automatic transfer switch complies with the requirements in 7.1.1 – 7.1.26, the switch shall be mounted in the intended manner and the normal and alternate supply terminals shall be connected to separate circuits of voltage and frequency in accordance with Table 15. The switch with no load connected shall be caused to operate by low normal supply voltage. | |
| 9.6.2 | New Added requirement that BCELTS mechanically held in the normal state shall meet the chatter performance test outlined in this clause. | |
| 9.7.1 | To determine whether an automatic transfer switch complies with the requirements in
7.1.24 – 7.1.26, the switch shall be mounted in the intended manner and the normal
and alternate supply terminals shall be connected to separate circuits of voltage and
frequency in accordance with Table 15. The marked minimum operating values of
voltage and frequency shall be verified by: a) Increasing alternate supply frequency with voltage set at minimum marked operating voltage, and b) Increasing the alternate supply voltage with frequency set at minimum marked operating frequency. | |
| 9.7.2 | A closed-transition transfer switch shall be mounted in the intended manner and the
normal and alternative supply terminals shall be connected to separate circuits of
voltage and frequency in accordance with Table 15. The switch with no load
connected shall be caused to attempt to operate under the following conditions: a) Open-transition mode; b) Closed-transition mode with sources in synchronization; c) Closed-transition mode with sources not in synchronization with respect to voltage; d) Closed-transition mode with sources not in synchronization with respect to frequency; and e) Closed-transition mode with an external supply or shunt switch or equivalent method to simulate an extended parallel operation. | |
| 9.8.1 | When tested under the conditions described in 9.8.2 – 9.8.12, transfer switches shall not attain a temperature at any point high enough to constitute a risk of fire or to damage any materials employed in the device, and shall not show temperature rises at specific points greater than those indicated in Table 16. | |
| 9.8.9 | Temperatures shall be measured by thermocouples consisting of wires no larger than 0.21 mm2 (24 AWG) and no smaller than 0.05 mm2 (30 AWG), applied to the hottest accessible parts. When thermocouples are used in determining temperatures in electrical equipment, thermocouples consisting of 30 AWG iron and constantan wire and a potentiometer-type instrument shall be used whenever referee temperature measurements by thermocouples are necessary. The thermocouple wire shall conform to the requirements for special thermocouples as listed in the table of limits of error of thermocouples in Annex A1, Item 17. The thermocouples and related instruments shall be accurate and calibrated in accordance with good laboratory practice. | |
| 9.8.9.1 | The primary (preferred) method of measuring the temperature of a coil is the resistance method as specified in 9.8.11, but temperature measurements by either the thermocouple or resistance method are acceptable, except that the thermocouple method shall not be employed for a temperature measurement at any point at which supplementary insulation is employed. | |
| 9.8.10 | The temperature readings shall be obtained by means of thermocouples and an indicating instrument. A temperature is considered to be constant when three successive readings, taken at intervals of 10 percent of the previous elapsed duration of the test, but not less than 10-minute or more than 20-minute intervals, indicate that stable conditions have been reached. | |
| 9.8.11 | The resistance method consists of the determination of the temperature of a copper or aluminum winding by comparing the resistance of the winding at the temperature to be determined with the resistance at a known temperature, according to the formula in this sub-clause. | |
| 9.8.12 | Unless the resistance can be measured with the device energized, the value of “R” at shutdown shall be determined by taking several resistance measurements at short intervals, beginning as quickly as possible after the instant of shutdown. A curve of the resistance values and the time may be plotted and extrapolated to give the value of “R” at shutdown. | |
| 9.9.1 | A transfer switch device shall be capable of withstanding for 1 minute without
breakdown the application of 1000 Vac plus twice maximum rated voltage at a
frequency in accordance with Table 15: a) Between uninsulated live parts and the enclosure with the switch alternately closed to each supply source, b) Between terminals of opposite polarity with the switch in the normal supply to load position, c) Between terminals of opposite polarity with the switch in the alternate supply position, d) Between uninsulated live parts of different circuits, e) Between terminals of normal source and alternate source with the switch in the normal supply position, and f) Between terminals of normal source and alternate source with the switch in the alternate supply position. | |
| 9.10.1.4 | The minimum on time in each contact position shall be 0.167 second, unless automatic tripping of the overcurrent device occurs. | |
| 9.10.3.1 | Clause revised to refer to Table 15 with regard to frequency of the test circuit | |
| 9.13.2.3 | Clause revised to allow a separate main device to be used when all conditions (a) to (c) are met. | |
| 9.13.3.3 | In Mexico and the United States, for transfer switches intended for optional standby systems only, the transfer switch shall be capable of being operated by its intended means as demonstrated by (a) – (e) in this subclause. | |
| 9.13.3.10 | Clause revised to require transfer switches rated 100A or less to meet all conditions in order to use a separate main device to terminate the rated short-circuit capacity (withstand) test of Clause 9.13.3. | |
| 9.13.3.11 | Other than as noted in 9.13.3.12 or 9.13.3.13, for a time duration test, the test current shall pass through the transfer switch for at least 0.050 seconds. The transfer switch markings shall be as specified in 5.2.4.1. The marked time duration shall be equal to 0.050 seconds. | |
| 9.13.3.12 | Clause revised to allow different pass through current times for transfer switches rated 100A or less for an available short circuit current rating of 10,000A or less. | |
| 9.13.3.18 | A transfer switch intended for use on an alternating-current system shall be tested with alternating current at a frequency in accordance with Table 15 on a circuit as indicated in Figure 9.13.3.1. The test shall be performed in accordance with (a) – (f) of this subclause. | |
| 9.15.2.3 | A transfer switch intended for use on an alternating current system shall be tested with alternating current at a frequency in accordance with Table 15. The circuit shall be as indicated in Figure 9.13.3.1. The test shall be performed in accordance with the (a) – (e) of this subclause. | |
| D3.1 | The performance of bypass/isolation switches shall be investigated by subjecting a representative sample or samples in commercial form to the tests described in D4 – D12. Unless otherwise indicated, the various tests shall be conducted at the test frequency and at the test potential indicated in Table 15. | |
| D7.1 | In Mexico and the United States, other than as noted in D7.2, a bypass/isolation switch shall perform acceptably when subjected to an endurance test in accordance with the Endurance test, 9.12. In Canada, this requirement does not apply. | |
| E1.4 | In Canada, fire pump transfer switches may not be marked as suitable for service entrance. In Mexico and the United States, this requirement does not apply. | |
| E2.3 | In Canada, a disconnecting means shall be installed within the transfer switch enclosure or compartment, and shall be located ahead of the alternate supply terminals. In Mexico and the United States, a disconnecting means is optional. A disconnecting means shall comply with either E2.3(a) or E2.3(b). | |
| G7.6 | A Softload ATS not marked for use as an optional standby transfer switch shall comply with (a) – (c) of this subclause. In only, the requirements of G7.6 shall apply for all Softload ATS. | |
| G9.3 | Operation on loss of supply voltage when operating in the parallel mode – To
determine whether an automatic transfer switch complies with the requirements of
G7.6(a), the switch shall be mounted in the intended manner and the normal and
alternate supply terminals shall be connected to separate circuits of voltage and
frequency in accordance with Table 15. The switch operating in parallel mode with
no load connected shall be caused to operate by the following means: a) Interrupting and then restoring, in turn, each conductor of the normal supply, b) Interrupting and then restoring, in turn, each conductor of the alternate supply | |
| Fig. J1 | Conductors through openings | |
| Fig. J2 | Circuit for short circuit withstand test | |
| Fig. J3 | Line connection for tests | |
| Table 2 | Marking locations | |
| Table 3 | Minimum acceptable spacings in millimeters (inches) | |
| Table 4 | Table revised to indicate that spacings apply for U.S. and Mexico only, not Canada (in C22.2 178.1-12, Table 4 was specified for Canada only) | |
| Table 6 | Assumed maximum short-circuit current ratings for unmarked components | |
| Table 11 | Table revised to indicate that the dimensions in the table do not apply to U.S. and Mexico | |
| Table 15 | Table revised to add a column for test frequency Note the “110-480” column in Table 15 in C22.2 No. 178.1-12 was an error and has been corrected to “440-480V” in the latest edition of the standard | |
| Table 16 | Table revised to allow 90C conductors for use on equipment marked for use with 60/75C wire provided the wire is sized in accordance with ampacity of wire at 75C | |
| Table 24 | Endurance test cycles for optional standby systems other than emergency and legally-required | |
| Table 27 | Added 0.008 and 0.017 short circuit current time duration | |
| Table J1 | Size of equipment grounding conductors for grounding interior raceways and equipment | |
| Table J2 | Maximum acceptable temperature rises | |
| Section 6.20 | (Title Only) Inlets for generator connection | |
| Section G10 | UL 1008 TR2 (Title Only) Manufacturing and Production Tests | |
| Annex J | New Added new normative annex for inlet assemblies for transfer switch equipment. | |
CUSTOMERS PLEASE NOTE: This Table and column "Verdict" can be used in determining how your current or future production is or will be in compliance with new/revised requirements.