Where the operation of the equipment can be programmed, detailed information on methods of programming, equipment required, program verification, and additional safety procedures (where required) shall be provided.
Maintenance manual
The technical documentation shall contain a maintenance manual detailing proper procedures for adjustment, servicing and preventive inspection, and repair. Recommendations on maintenance/service intervals and records should be part of that manual. Where methods for the verification of proper operation are provided (for example software testing programs), the use of those methods shall be detailed.
Parts list
The parts list, where provided, shall comprise, as a minimum, information necessary for ordering spare or replacement parts (for example components, devices, software, test equipment, technical documentation) required for preventive or corrective maintenance including those that are recommended to be carried in stock by the user of the equipment.
18 Verification
General
This part of IEC 60204 gives general requirements for the electrical equipment of machines.
The extent of verification will be given in the dedicated product standard for a particular machine. Where there is no dedicated product standard for the machine, the verifications shall always include the items a), b) and f) and may include one or more of the items c) to e):
verification that the electrical equipment complies with its technical documentation;
in case of protection against indirect contact by automatic disconnection, conditions for protection by automatic disconnection shall be verified according to 18.2;
insulation resistance test (see 18.3);
voltage test (see 18.4);
protection against residual voltage (see 18.5);
functional tests (see 18.6).
When these tests are performed, it is recommended that they follow the sequence listed above.
When the electrical equipment is modified, the requirements stated in 18.7 shall apply.
The tests shall be carried out by measuring equipment in accordance with relevant IEC standards. For tests in accordance with 18.2 and 18.3, measuring equipment in accordance with the IEC 61557 series is applicable.
The results of the verification shall be documented.
Verification of conditions for protection by automatic disconnection of supply
General
The conditions for automatic disconnection of supply (see 6.3.3) shall be verified by tests.
For TN-systems, those test methods are described in 18.2.2; their application for different conditions of supply are specified in 18.2.3.
For TT and IT systems, see IEC 60364-6-61.
Test methods in TN-systems
Test 1 verifies the continuity of the protective bonding circuit. Test 2 verifies the conditions for protection by automatic disconnection of the supply.
Test 1 - Verification of the continuity of the protective bonding circuit
The resistance of each protective bonding circuit between the PE terminal (see 5.2 and Figure 2) and relevant points that are part of each protective bonding circuit shall be measured with a current between at least 0,2 A and approximately 10 A derived from an electrically separated supply source (for example SELV, see 413.1 of IEC 60364-4-41) having a maximum no-load voltage of 24 V a.c. or d.c.. It is recommended not to use a PELV supply since such supplies can produce misleading results in this test. The resistance measured shall be in the expected range according to the length, the cross sectional area and the material of the related protective bonding conductor(s).
NOTE 1 Larger currents used for the continuity test increases the accuracy of the test result, especially with low resistance values, i.e. larger cross sectional areas and/or lower conductor length.
Test 2 - Fault loop impedance verification and suitability of the associated overcurrent protective device
The connections of the power supply and of the incoming external protective conductor to the PE terminal of the machine, shall be verified by inspection.
The conditions for the protection by automatic disconnection of supply in accordance with 6.3.3 and Annex A shall be verified by both:
verification of the fault loop impedance by:
calculation, or
measurement in accordance with A.4, and
confirmation that the setting and characteristics of the associated overcurrent protectivedevice are in accordance with the requirements of Annex A.
NOTE 2 A fault loop impedance measurement can be carried out for circuits where the conditions of protection by automatic disconnection requires a current Ia up to about 1 kA (/a is the current causing the automatic operation of the disconnecting device within the time specified in Annex A).
Application of the test methods for TN-systems
Test 1 of 18.2.2 shall be carried out on each protective bonding circuit of a machine.
When Test 2 of 18.2.2 is carried out by measurement, it shall always be preceded by Test 1.
NOTE A discontinuity of the protective bonding circuit can cause a hazardous situation for the tester or other persons, or damage to the electrical equipment during the loop impedance test.
The tests that are necessary for machines of different status are specified in Table 9. Table 10 can be used to enable determination of the machine status.
Table 9 - Application of the test methods for TN-systems
|
Procedure |
Machine status |
Verification on site |
|
A |
Electrical equipment of machines, erected and connected on site, where the continuity of the protective bonding circuits has not been confirmed following erection and connection on site. |
Test 1 and test 2 (see 18.2.2) Exception: If previous calculations of the fault loop impedance or resistance by the manufacturer are available and where:
Test 1 (see 18.2.2) of the protective bonding circuits connected on site and verification by inspection of the connections of the power supply and of the incoming external protective conductor to the PE-terminal of the machine is sufficient. |
|
В |
Machine supplied with confirmation of the verification (see 18.1) of continuity of the protective bonding circuits by test 1 or test 2 by measurement, having protective bonding circuits exceeding the cable length for which examples are given in Table 10.
|
Test 2 (see 18.2.2) Exception: Where it can be confirmed that the supply source impedance on site is less than or equal to that used for the calculation, or that of the test supply during a test 2 by measurement, no test is required on site apart from verification of the connections:
|
|
C |
Machine having protective bonding circuits not exceeding the cable length for which examples are given in Table 10, supplied with confirmation of the verification (see 18.1) of continuity of the protective bonding circuits by test 1 or test 2 (see 18.2.2) by measurement. Case C1) supplied fully assembled and not dismantled for shipment. Case C2) supplied dismantled for shipment, where the continuity of protective conductors is ensured after dismantling, transportation and reassembly (for example by the use of plug/socket combination(s)). |
No test required on site. For a machine not connected to the power supply by a plug/socket combination, the correct connection of the incoming external protective conductor to the PE-terminal of the machine shall be verified by visual inspection. In case C2), the installation documents (see 17.4) shall require that all connections of the protective conductor(s) that were disconnected for shipment are verified, for example by visual inspection. |
Table 10 - Examples of maximum cable length from each protective device to its load
|
1 Supply source impedance to each protective device |
2 Cross-sectional area |
3 Nominal rating or setting of the protective device |
4 Fuse disconnect time 5 s |
5 Fuse disconnect time 0,4 s |
6 Miniature circuitbreaker char.B 37a= 5 x /Ndisconnect time 0,1 s |
7 Miniature circuitbreaker char.C 47a= 10x/Ndisconnect time 0,1 s |
8 Adjustable circuit-breaker /a= 8 x 7ndisconnect time 0,1 s |
|
mO |
mm2 |
A |
Maximum cable length in m from each protective device to its load |
||||
|
500 |
1,5 |
16 |
97 |
53 |
76 |
30 |
28 |
|
500 |
2,5 |
20 |
115 |
57 |
94 |
34 |
36 |
|
500 |
4,0 |
25 |
135 |
66 |
114 |
35 |
38 |
|
400 |
6,0 |
32 |
145 |
59 |
133 |
40 |
42 |
|
300 |
10 |
50 |
125 |
41 |
132 |
33 |
37 |
|
200 |
16 |
63 |
175 |
73 |
179 |
55 |
61 |
|
200 |
25 (line)/16 (PE) |
80 |
133 |
|
|
|
38 |
|
100 |
35 (line)/16 (PE) |
100 |
136 |
|
|
|
73 |
|
100 |
50 (line)/25 (PE) |
125 |
141 |
|
|
|
66 |
|
100 |
70 (line)/35 (PE) |
160 |
138 |
|
|
|
46 |
|
50 |
95 (line)/50 (PE) |
200 |
152 |
|
|
|
98 |
|
50 |
120 (line)/70 (PE) |
250 |
157 |
|
|
|
79 |
|
The values of the maximum cable length in Table 10 are based on the following assumptions:
A deviation from these assumptions can require a complete calculation or measurement of the fault loop impedance. Further information is available from IEC 60228 and IEC 61200-53. |
|||||||
Insulation resistance tests
When insulation resistance tests are performed, the insulation resistance measured at 500 V d.c. between the power circuit conductors and the protective bonding circuit shall be not less than 1 MQ. The test may be made on individual sections of the complete electrical installation.
Exception: for certain parts of electrical equipment, incorporating for example busbars, conductor wire or conductor bar systems or slip-ring assemblies, a lower minimum value is permitted, but that value shall not be less than 50 kQ.
lf the electrical equipment of the machine contains surge protection devices which are likely to operate during the test, it is permitted to either:
disconnect these devices, or
reduce the test voltage to a value lower than the voltage protection level of the surge protection devices, but not lower than the peak value of the upper limit of the supply (phase to neutral) voltage.
Voltage tests
When voltage tests are performed, test equipment in accordance with IEC 61180-2 should be used.
The test voltage shall be at a nominal frequency of 50 Hz or 60 Hz.
The maximum test voltage shall have a value of twice the rated supply voltage of the equipment or 1 000 V, whichever is the greater. The maximum test voltage shall be applied between the power circuit conductors and the protective bonding circuit for a period of approximately 1 s. The requirements are satisfied if no disruptive discharge occurs.
Components and devices that are not rated to withstand the test voltage shall be disconnected during testing.
Components and devices that have been voltage tested in accordance with their product standards may be disconnected during testing.
Protection against residual voltages
Where appropriate, tests shall be performed to ensure compliance with 6.2.4.
Functional tests
The functions of electrical equipment shall be tested.
The function of circuits for electrical safety (for example earth fault detection) shall be tested.
Retesting
Where a portion of the machine and its associated equipment is changed or modified, that portion shall be reverified and retested, as appropriate (see 18.1).
Particular attention should be given to the possible adverse effects that retesting can have on the equipment (for example overstressing of insulation, disconnection/reconnection of devices).Annex A
(normative)
Protection against indirect contact in TN-systems
(Derived from IEC 60364-4-41:2001, and IEC 60364-6-61:2001)
A.1 General
Protection against indirect contact shall be provided by an overcurrent protective device that automatically disconnects the supply to the circuit or equipment in the event of a fault between a live part and an exposed conductive part or a protective conductor in the circuit or equipment, within a sufficiently short disconnecting time. A disconnecting time not exceeding 5 s is considered sufficiently short for machines.
Exception: Where this disconnecting time cannot be assured, measures shall be implemented (for example supplementary protective bonding) to prevent a prospective touch voltage from exceeding 50 V a.c. or 120 V ripple-free d.c. between simultaneously accessible conductive parts. See A.3.
For circuits which supply, through socket-outlets or directly without socket-outlets, Class I hand-held equipment or portable equipment (for example socket-outlets on a machine for accessory equipment, see 15.1) Table A.1 specifies the maximum disconnecting times that are considered sufficiently short.
Table A.1 - Maximum disconnecting times for TN systems
|
t/oa> V |
Disconnecting time s |
|
120 |
0,8 |
|
230 |
0,4 |
|
277 |
0,4 |
|
400 |
0,2 |
|
>400 |
0,1 |
|
a> Uo is the nominal a.c. r.m.s. voltage to earth. NOTE 1 For voltages which are within the tolerance band stated in IEC 60038, the disconnecting time appropriate to the nominal voltage applies. NOTE 2 For intermediate values of voltage, the next higher value in the above table is to be used. |
|
А.2 Conditions for protection by automatic disconnection of the supply by overcurrent protective devices
The characteristics of overcurrent protective devices and the circuit impedances shall be such that, if a fault of negligible impedance occurs anywhere in the electrical equipment between a phase conductor and a protective conductor or exposed conductive part, automatic disconnection of the supply will occur within the specified time (i.e. <, 5 s or < values in accordance with Table A.1). The following condition fulfils this requirement:
Zs x /a — Ц)
where
Zs is the impedance of the fault loop comprising the source, the live conductor up to the point of the fault and the protective conductor between the point of the fault and the source;
Ia is the current causing the automatic operation of the disconnecting protective device within the specified time;
Uo is the nominal a.c. voltage to earth.
The increase of the resistance of the conductors with the increase of temperature due to the fault current shall be taken into account (see A.4.3).
NOTE Information for calculating short circuit currents can be found in, for example, the IEC 60909 series or from suppliers of short-circuit protective devices.
A.3 Condition for protection by reducing the touch voltage below 50 V
Where the requirements of Clause A.2 cannot be assured and supplementary bonding is selected as the means of ensuring protection against hazardous touch voltages, the condition for this protection is that the touch voltage has been reduced to below 50 V and it is achieved when the impedance of the protective circuit (ZPE) does not exceed:
zpe s77Txzs
where ZPE is the impedance of the protective bonding circuit between the equipment anywhere in the installation and the PE terminal of the machine (see 5.2 and Figure 2) or between simultaneously accessible exposed conductive parts and/or extraneous conductive parts.
Confirmation of this condition can be achieved by using the method of Test 1 of 18.2.2 to measure the resistance APE. The condition for protection is achieved when the measured value of ЛРЕ does not exceed:
where
/a(5sj is the 5 s operating current of the protective device;
ЛРЕ is the resistance of the protective bonding circuit between the PE terminal (see 5.2 and
Figure 2) and the equipment anywhere on the machine, or between simultaneously accessible exposed conductive parts and/or extraneous conductive parts.
NOTE 1 Supplementary protective bonding is considered as an addition to protection against indirect contact.
NOTE 2 Supplementary protective bonding may involve the entire installation, a part of the installation, an item of apparatus, or a location.
A.4 Verification of conditions for protection by automatic disconnection of the
supply
A.4.1 General
The effectiveness of the measures for protection against indirect contact by automatic disconnection of supply in accordance with Clause A.2 is verified as follows:
- verification of the characteristics of the associated protective device by visual inspection of the nominal current setting for circuit-breakers and the current rating for fuses, and;
