Questions tagged [iec]
The iec tag has no usage guidance.
32
questions
0
votes
0
answers
36
views
Why there are no IEC C8 to NEMA 1-15R cables?
Conntek has an IEC C8 to 1-15R adapter. C8 to CEE7/16 cables are dime a dozen on Aliexpress. Yet there are no C8 to 1-15R cables as far as I can tell. Is there an electronics/standard reason ...
- 336
1
vote
0
answers
32
views
Does the use of an IEC line connector on equipment require a UL cert?
My client wants to use a 12V SLA with a built-in line-powered charger in his gear. If I add an IEC AC mains line connector does this turkey now have to go through cert?
1
vote
1
answer
92
views
Can an unpolarised (C7) plug be used safely in place of a polarised (C7P) plug?
I bought this AC adapter from the US to replace a broken Australian one. Unfortunately, the power brick is keyed for use with the polarised C7P plug. Unpolarised C7 appears to be the standard in ...
4
votes
2
answers
180
views
Determination of temperature rise - Deviation of ± 5 K
I was referring IEC 61439-1 standard for the deriving the temperature rise of an assembly through comparison. We can derive the current rating of an assembly (low voltage switchboard) at any point (...
- 307
2
votes
1
answer
83
views
What is meant by the statement "variation at all measured points (including the ambient air temperature) does not exceed 1K/h"?
I am trying to understand a temperature rise test that is being conducted over a switchboard. The test conforms to IEC 61439-1. The clause 10.10.2.3.1 (Method of test - General) regarding the ...
- 307
1
vote
1
answer
93
views
Why is the temperature sometimes expressed as a difference between two values and not an absolute value?
I was going through an IEC standard - 61439-1, table 6.
For aluminum, the standard specifies the value as 55K which is a temperature rise.
IEC 60085 specifies the class B insulator absolute value as ...
1
vote
0
answers
45
views
IEC 61000-3-3 flicker for switches and relays
IEC 61000-3-3 shall be used for testing all 230V 50Hz AC devices with up to 16A current rating.
What about switches, relays, power plugs-basically devices that act as gateways between mains and actual ...
- 141
1
vote
0
answers
193
views
What are the differences between UL1581 and UL2556 for VW-1 (Vertical Flame Test)?
In IEC62368-1, it's stated:
Wire complying with UL 2556 VW-1 is considered to comply with these
requirements.
I've asked a manufacturer if he could meet these requirements and he answered that he ...
- 145
0
votes
1
answer
81
views
Voltage protection level Up of SPD (surge protection device)
I was going through the datasheet of the below SPD.
https://www.phoenixcontact.com/en-pc/products/type2-surge-arrester-val-sec-t2-3c-350-fm-2905339
It says, Voltage protection level Up ≤ 1.5 kV
It ...
- 1
0
votes
0
answers
93
views
IEC 60664-1 2020.Table F.5 / for creepage
In IEC 60664-1 2020.Table F.5 / for creepage
Does printed wiring material mean not only bareboard but also component mounted on Board?
If not, why?
- 11
1
vote
0
answers
157
views
IEC 60664-1. Rated impulse withstand voltage
In IEC 60664-1:2020 table F.1 (Rated impulse withstand voltage for equipment energized directly from the mains supply)
For 1250V, the calculated Rated Impulse with stand Voltage value is equal to ...
- 11
3
votes
3
answers
339
views
Why are switchgears rated in specific capacities such as 63A, 100A, 125A and so on?
I am working in a consultant industry, wherein we get the switchgears from different OEMs. I wonder why the switchgears (including fuses and fuse-gears) and control gear assemblies are rated in the ...
- 307
1
vote
4
answers
138
views
Can I convert a stereo receiver's hard-wired two-prong power cord to an IEC C7?
enter image description hereenter image description here
Repairs to my stereo receiver require considerable disassembly.
One step requires me to unsolder the two mains leads from posts on the main ...
0
votes
0
answers
56
views
Why are some devices labelled Class II instead of Class III despite using ELV?
For example, my table lamp has an IEC 61140 Class II marking despite it being externally supplied with 24V.
- 121
4
votes
1
answer
136
views
Double insulation for battery operated device
I work for a lab device manufacturing firm. During the testing of our electronic pipette according to IEC 61010-1,the safety test lab asked why it did not have the symbol indicating double insulation.
...
- 81
0
votes
0
answers
440
views
Is there any kind of “motor current/load limit curve”, like the one for wires?
When we try to select a motor protective circuit breaker (for an IEC induction motor), we can compare its tripping curve to the motor’s time-current curve during starting and steady-state. To avoid ...
- 37
0
votes
0
answers
115
views
AC/AC power supply for PCB
I am trying to source the right setup for powering this PCB:
I have found an 18 V AC/AC power supply but it has a barrel connector:
I am struggling to work out how to connect the barrel connector to ...
6
votes
2
answers
761
views
How do we calculate the sub-transient current (initial symmetrical short-circuit current)?
For the ease of understanding, I have divided my questions into two sub-parts:
Per IEC 60909, the initial symmetrical short circuit current is calculated by: \$I_k"=\frac{cU_n}{\sqrt(3)Z_k}\$. ...
- 307
2
votes
2
answers
3k
views
How to hook up a transformer to 120V AC?
I'm building a DC power supply and am stepping down my voltage from 120V (from the outlet) to 24V through a transformer. I will be soldering the 3 wires that plug into a North American electrical ...
1
vote
0
answers
168
views
24V DC Industrial equipment - which IEC standards to comply with
I'm trying to design a commercial industrial product/PCB for the first time.
In order to do it "right", I would like to be aware about the most common IEC / IPC standards to comply with. ...
- 1,802
0
votes
2
answers
75
views
Is there any standard or norm for this situation?
Considering a metallic enclosure(which has PSU and electronics in it) with an IEC mains socket, an example shown below:
And it uses an IEC power socket such as:
For this kind of enclosure is there ...
- 2,071
2
votes
1
answer
257
views
Must the device I am developing conform with IEC 61010-1:2010 standard?
I am developing a device that contains 5 inputs (piezo buttons) and 5 outputs (2x pump - induction motor, fan - induction motor with basic speed control using dimmer circuit, 2x source for LED ...
- 43
0
votes
0
answers
114
views
IEC 60664-1 clearance between phase and earth
With IEC 60664-1 you require clearance between phase and earth.
But if you have a resistor voltage divider between phase and earth do you need the same clearance between the pads of the resistors?
Or ...
- 49
1
vote
1
answer
3k
views
IEC 61010 table for creepage distances
Good day
I am making a pcb layout that is required to comply with the IEC 61010-1. In the standard, there is a table for clearances and creepages, which depends on working voltage, pollution degree ...
- 401
1
vote
1
answer
4k
views
How to calculate power loss & voltage drop in three-phase power cables
What is the correct formula/method to calculate cable power losses in a three-phase system? I'm unable to find any IEC standard outlining the same.
If you consider 3C/4C cables, the manufacturer ...
- 11
1
vote
0
answers
68
views
What are the IEC standards/certifications to look for in a DSO while making measurements pertaining analog parameters like CMRR, SNR, THD etc
I am in the process of measuring CMRR for our mixed signal system that deals with bio-signal acquisition. I am using DSOX2014A keysight entry-level oscilloscope to make measurement to derive CMRR, SNR ...
3
votes
0
answers
126
views
Why are computer displays Class I devices but TVs Class II?
I was wondering why all computer displays I know are Class I devices, or at least come with a Schuko plug, while all TVs I know are double insulated Class II devices?
I understand it might have ...
- 151
0
votes
2
answers
1k
views
Do I need to insulate down conductors in a lightning protection system?
When we install seperate down conductors in an external lightning protection system, do we need to fully insulate it or need to insulate in touchable areas? Is there any requirements in IEC 62305 ...
- 135
1
vote
1
answer
127
views
When does an electrical product get an RU (Underwriters Laboratories) certified mark?
If you take an example of contactor, it can be used in residential, industrial, electric vehicle applications etc.
Let's say the contactor has passed the UL standards corresponding to the industrial ...
2
votes
1
answer
1k
views
Do we have equivalent standards for all UL standards under IEC?
As per the image, it looks like there will be an alternative standard in IEC with respect to every UL standard?
0
votes
2
answers
221
views
United Kingdom Split Phase Transformer / Centre Tapped Earthed (CTE) / 55V - 0V - 55V - How do you wire the connector?
I'm working on a weird project which involves making a custom cable for a British CTE Transformer. For those not in the know, these transformers are typically used at jobsites to provide 110V power. ...
- 31
1
vote
0
answers
125
views
IEC grounding and bonding standard
Is there an equivalent standard in IEC such as UL 467 or IEEE 837 which talks about the various test procedure for bonding clamps? Is IEC 61914:2015 similar to UL 467?
