IEC 60076-22-1-2019 pdf download.Power transformers — Part 22-1: Power transformer and reactor fittings — Protective devices
Transformateurs de puissance — Partie 22-1: Accessoires pour transformateurs de puissance et bobines d’inductance — Dispositifs de protection.
The manufacturer shall perform a test to prove the device will not leak in operation. The description of the test procedure shall be made available to the customer, on request.
The test performed by the manufacturer shall be at least as reliable as a helium leakage test with a leakage rate lower than 4 10-6 Pa m3/s.
7.4.3.2.2 Insulation test
The manufacturer shall perform a short duration (60 s) power frequency withstand voltage test between independent circuits and between the circuit and the earth.
Test voltage is given in Table 1.
7.4.3.2.3 Functional test
A functional test shall be carried out to prove the mechanical and electrical operation of the indicator and associated switches.
The maximum tolerance on the switch setting and the dial indication is 5 (angle).
7.4.3.3 Type test
7.4.3.3.1 Vacuum withstand test
The devices shall be subjected to a vacuum test of an absolute pressure of 2,5 kPa for 24 h. This test shall be followed by the test as detailed in 7.4.3.2.3.
7.4.3.3.2 Vibration withstand test
The device shall be subjected to vibrations in accordance with 4.6: no operation of the switches shall be recorded.
7.4.3.4 SpecIal tests — Seismic withstand test
Upon customer request, the device shall withstand seismic test in accordance with 4.7.
7.5 LiquId flow indicators
7.5.1 Mechanical requirements
7.5.1.1 Nameplate
The nameplate shall contain the following information:
7.5.1.2 ConstructIon details
These devices are not intended to measure the flow rate, but only to detect the flow above or
under the setting point.
The supplier shall give the direction of liquid flow depending on the mounting position either by an arrow marked on the body or the dial, or by any other suitable means.
The device shall be provided with a visual indication. If the indication is by dial and pointer, the movement of the pointer from no flow to flow position shall be clockwise when facing the dial.
The mounting arrangement of the indicator shall be such that it can be dismantled and removed from the outside of the pipe.
It shall be possible to maintain or replace switches, without draining the pipe.
The Indicator shall be equipped with a minimum of one switch of the normally open, normally closed or changeover type upon agreement, which changes its status when the sensor actuates. Additional sets of switches shall be provided if required.
7.5.1.3 Terminal box
A terminal box shall be provided to connect the switches of the device: it shall include also one protective conductor or earth terminal. The number and marking of the terminals shall comply with the connection diagram.
The terminals shall be designed to accept cables having a cross sectional area of between 1,5 mm2 and 4 mm2.
A minimum of one threaded hole for cable glands M25 x 1,5 shall be provided. Other thread dimensions are subject to agreement between supplier and purchaser. Cable glands are supplied on demand.
7.5.1.4 Construction types
7.5.1.4.1 Magnetic coupling type constructions
In this construction, the interface between the paddle movement and the visual indication Is by magnetic coupling.
7.5.1.4.2 Mechanical coupling type construction.IEC 60076-22-1-2019 pdf download.Power transformer and reactor fittings — Protective devices