1 Scope
This document specifies the requirements and information on the use of direct disconnect position switches. This document applies to direct disconnect position switches for standard loads or minor loads.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Among them, note the date of the reference document, only the date of the corresponding version of the wood applicable to the wood document; do not note the date of the reference document, the latest version of its wood (including all the revision of the list) applicable to this document.
GB/T 14048.5-2017 Low-voltage switchgear and controlgear Part 5-1: Control circuit appliances and switching elements - Electromechanical control circuit appliances
GB/T 15706 General rules for the safe design of machinery Risk assessment and risk reduction
GB/T 18831 Principles for the design and selection of interlocking devices related to mechanical safety and guarding devices
3 Terms and definitions
The terms defined in GB/T 15706 and GB/T 18831 and the following terms and definitions apply to this document.
4 Requirements
4.1 General requirements
The direct disconnect position switch shall meet the requirements of Appendix K in GB/T 14048.5-2017.
4.2 Structural requirements
In a direct break position switch, the parts that perform the direct mechanical action to break the contacts shall be of rigid construction.
Figure 1 and Figure 2 give examples of the structure of a direct break position switch for a type 1 interlocking device and a type peal interlocking device respectively.
4.3 Safety requirements
4.3.1 Average number of dangerous failure cycles
The B;on value of the direct disconnect position switch shall be at least 2000 000 cycles. Note 1:If troubleshooting of the direct disconnection action is possible.
The manufacturer shall provide a Bpop and/or a performance level (PL) according to Bo in the product specification.
Note 2: For the determination of PI, see GB/T 16855.1.
4.3.2 Direct disconnection function
The direct break contact should be reliably disconnected and remain disconnected as long as the actuator is in the disconnected position.
4.3.3 Reducing the possibility of being bypassed
The direct opening position switch should ensure that its safety function cannot be bypassed by simple or conventional means. In the case of type 1 direct disconnect position switches, measures can be taken during installation to prevent their function from being disabled.
For direct disconnect position switches of type PAK, it should be ensured that the state of the switch cannot be changed by a simple mechanical switch, by hand or by conventional objects if the contacts are broken (e.g. by means of a code).
Note more information on preventing bypass - see chapter GB/T 18831-2017.
4.3.4 Direct disconnection forces
The forces to which the direct disconnection position switch can be subjected should take into account the dimensions of the actuator, the enclosure, the environmental conditions of the installation and the intended use.
4.4 Electromagnetic compatibility (EMC)
The direct disconnect position switch shall comply with the requirements of 7.3 of GB/T 14048.5-2017 regarding electromagnetic compatibility.
4.5 Additional requirements for Type 2 interlocking devices in high demand or continuous mode
4.5.1 General requirements
In addition to the requirements specified in 4.l to 4.4, the following requirements shall be fulfilled when the direct disconnect position switch is used in high or continuous mode.
Note: See 3.1.38 in GB/T 16855.1-2018 for the definition of high demand or continuous mode.
4.5.2 Actuation systems/direct disconnection systems
4.5.2.1 General requirements
When the direct disconnect position switch is used in a demanding or continuous mode and the contacts are not encapsulated inside the housing (e.g. in a monolithic housing), the contacts should not be removable by simple tools and care should be taken to prevent accidental loosening during installation.
4.5.2.2 Switching strength
When the break contact of the direct disconnect position switch is in the closed position, the actuation system must not be damaged by an opening force of at least 1000 N and the actuator (actuator) must remain in the closed position.
After unlocking, the direct disconnect position switch shall show no damage that would reduce the safety performance and the corresponding function shall remain intact.
4.5.2.3 Strength of the actuating mechanism (actuator)
If the direct opening position switch is to be used in demanding or continuous mode applications, the actuator shall be made of metal and shall not be subjected to a vertical impact load of 6.35 J on one side of the actuator, which would cause significant deformation and damage to the actuator.
4.5.3 Contact units
If the direct break position switch is to be used in demanding or continuous mode applications, it shall have two sets of direct break contacts.
4.5.4 Enclosure protection class
If the direct break position switch is to be used in demanding or continuous mode applications, it shall have a minimum protection class of IP 65.
5 Information on use
5.1 General requirements
The information provided by the manufacturer of the direct disconnect position switch to the user and its presentation shall comply with 6.4 of GB/T 15706-2012.
Note: For further information on information for use, see 1SO 20607:2019.
5.2 Enclosure marking
On the housing of the direct disconnect position switch, the following information shall be permanently and clearly given by means of a marking with a character height of not less than 2 mm :
a) the name of the manufacturer;
b) Name of the product;
c) Model number
d) date of manufacture;
e) direct disconnection symbol
f) Enclosure protection class (IP code);
g) Electrical parameters;
h) the standard implemented.
If there is not enough space, the manufacturer's full address and the product name may be given by means of a label attached to the product, but the rest of the information should be given on the enclosure.
5.3 Instructions for use
The operating instructions shall include at least the following: a) the name of the manufacturer and the place of origin;
b) the name of the product
c) a schematic diagram of the construction principle;
d) general description and intended use; e) instructions for assembly, installation and connection;
f) Electrical parameters (e.g. rated voltage, rated current, rated insulation voltage, etc.);
h) stroke, actuating force and holding force of the actuator
i) description of the fault characteristics (if required); j) maximum operating delay rate.
If the direct disconnect position switch is to be used in a demanding or continuous mode, the following information should be given in addition to the above: a description of the protection against dust accumulation (e.g. at the actuator head);
A description of the increased risk of contamination, e.g. if exposed to dusty environments, the actuator head should be mounted downwards;
Instructions for installation and wiring;
Instructions for the integration of position switches into the safety control system;
If necessary, instructions for the detection of cross-circuits;
Note that in Class C standards, if two independent position switches are required for the control of two channels, the switches cannot replace two
Note that this switch cannot replace two switches in a Class C standard where two independent position switches are required to control two channels;
Note that the maximum current in the switch should be half of the rated current in demanding applications.
Bibliography
Foreword
2 Normative references
3 Terms and definitions
4 Requirements
5 Information on use
Bibliography
