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Re: Unbalanced load sensor
I believe it’s through the tacho, increases and reductions in speed as the drum makes a rotation, as the motor makes many full rotations compared to the drum due to the pulley sizes it can compare multiple full rotation of the motor and and try to smooth out the peeks and drops in speed
Re: Does anyone use this loop tester info required
Brains wrote:Thank you for agreeing with me Stratford Girl.
When I read that these commercial organisations were allegedly promoting this practice, it did raise concerns.
If appliance ‘engineers’ cannot recognise the difference between TN & TT installations and cannot interpret loop impedance readings then I, for one, do wonder about the training for the individuals dealing with electrical appliances.
I am sure that someone will say that the concerns are unfounded as there are minimal incidents reported. Just wait until an MP’s relative is killed or injured. Everything will change. Much tighter regulation will then come in. Surely, as an industry, education and training must improve.
Regards
Just a note, having not worked for Indesit for a few years i have made a call and they now state that below 2 is acceptable regardless of the system and 3 to 200 is acceptable IF an RCD is fitted.
i did get that wrong.
i do agree it does make you wonder at times, but iv seen it in every industry iv been in people who are performing tests and repaired with no underlying background to how it works take Gas, i had my meter changed last year, a guy turned up in a ford fiesta wearing jeans and t shirt roughly 19 years old, walks in with a spanner and the meter, spends 5 minutes swapping it over, popped back to the car for the u gauge and did the test, i asked him a few questions and he had just got the job never working with gas before, had a 1 week coarse and that was it :eeek:as its the utility side no gas safe was required.
Re: Does anyone use this loop tester info required
i agree with everything you say, in fact i argued as much when i had my manufacture training years ago having just quit sparking but i learnt in reality having engineers try and figure out what system the customer is on is never going to happen, there has to be a line in the sand somewhere, Indesit and British Gas set it at 200ohm based on the fact in the majority of cases this is adequate to allow safe disconnect regardless of the system and if its in the regulation specified times or not.
This may not be 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} but from out point of view its enough.
Simply an engineer needs to know the socket is wired correctly, its earthed and there is a reasonable chance that in a fault condition the protecting device will work.
Re: Does anyone use this loop tester info required
Brains wrote:I would like to add my two-penny worth. I know that this will start some flack. :rolls:
100 ohms EFLI is far to high for any final circuit. When you take into account parallel paths created by Main Protective Bonding (even for a TT supply configuration) then one would expect a very much lower value.
The 100 ohm figure is normally the absolute max value for the external EFLI value at the origin of the supply. If you have measured external EFLI values in the region of 200 ohms then you may have unstable earth rod arrangement for a TT supply.
The typical EFLI max values you should be looking will be dependent on the controlling fuse or circuit breaker at the Consumer Unit.
So, why do we measure EFLI? This has not been clearly explained in any of the posts.
The reason to measure this value is to assure that the protective device (eg fuse or MCB) will clear within a specify period of time (for TN installations below 32A within 0.4 seconds) under fault conditions.
So for TN type installations,
16A type B MCB max EFLI is 2.87 ohms
20A type B MCB max EFLI is 2.30 ohms
32A type B MCB max EFLI is 1.44 ohms
40A type B MCB max EFLI is 1.15 ohmsWhen carrying out measurements always take 80{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of the above values as your working max. The 80{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} value is a generally recognised rule of thumb (ROT) value that takes into account things as installation and thermal conditions.
if a 30mA RCD is present, then you will need to use the ‘no-trip’ mode on the loop tester. The absolute max value here is 1667 ohms to earth. This value is determined by the max allowable touch voltage. L-N loop values are as detailed.
If you find a loop value that exceeds the above, advise your customer to have the installation checked. Better safe than sorry.
With regard to calibration, an acceptable verification method is to use a known socket, say, at home or the workshop. Record the values once a month and you can then see if the meter is drifting.
I could ramble on a bit more if so requested. Always pleased to help someone if needed.
Hope the above helps someone & adds clarity.
Regards
you are quite correct HOWEVER this is from a electricians point of view, these readings are the requirements to prevent death from direct electrocution to human or livestock, however this does not concern appliances,
on an appliance your concern is that should there be a earth fault the trip will fail with out fire or secondary electrocution from touching the chassis. this is why manufactures train there engineers to accept 100 or 200 ohms.
the second reason for this is the non trip testers, i spent 10 years performing periodic inspections, non trip is not a valid test as its readings can vary vastly compared to taking a true ZE (external fault loop test at the board) and Zs(internal earth loop) & R1 & R2.
We can go around in circles all year with this, the simplest way is how the manufactures recommend the tests, regardless of the system with or with out RCD a reading of 200ohm (some say 100) or under is acceptable for an Appliance engineer to deem the system safe for him to work on and allow the appliance to work safely
anything else is irrelevant
Re: Does anyone use this loop tester info required
No my point is legally your responsibility is with the appliance, obviously on BI the rules change and if there is a issue then as you say isolate and inform the customer of the issue.
Re: Does anyone use this loop tester info required
To a point I agree. I was a sparky for 10 years before moving to appliances , the more you dig into earth loop the deeper the hole goes unless your going to perform a full battery of tests that your not qualified to do you can never be certain
The simple way forward is to perform a test to ensure the socket is safe and your getting a reasonable reading. After that its down to you IF you inform the customer.
Your responsibility is with the appliance not the system.
Re: Does anyone use this loop tester info required
Nope I meant 200, I would advise anything above 100 should be investigated. The thing to remember is your testing at the socket and not the incoming earth. A true EL or ZE is taken from the earth where it enters the consumer unit, your testing it through a ring main and this has a affect
Regardless of the earth system if the system is fitted with an RCD then in theory an IR up to 1667 is perfectly safe as this is the maximum requirements for a TT (earth rod) system that’s classed a the least safe of the earth types
If there is no RCD then 200 is the maximum.
The best way is 200 for everything even though its higher than the maximum for TNCS,TNS systems the fault protection should still operate. If its an RCD then you doubly covered.
Re: Premature Bearing Failure
Iv been doing some research on seals. Iv found that on rotating shaft seals lip friction is the big issue. Depending on type of seal and lubrication life will vary vastly.
Looking into it manufactures seem to use different types. Some are oil seals designed to hold oil in, some of these have dust lips as well, others are liquid to liquid seals designed to separate two different liquids apart, the are also grease seals as well.
Interestingly the info made a point of the requirement to lubricate the seal lip where it meets the shaft, if there is a lack of lubrication or it dries up it carbonises and the seal over heats and fails. It also stated that the shaft has to be polished after manufacture to remove screw. When it made with a lathe there will be a natural screw in the direction of the way it was cut. If this it towards the seal contaminants will be pushed towards the seal and build up at its face as it rotates. Again causing failure.
I’m convinced the bearing failure is to do with seal failure as well. When changing them on the Hotpoint WMA with the stainless steel spider that shaft is always badly corroded, that must the cut into the seal and it will pass water. The quality of the stainless steel used has to have an impact.
I’m convinced that if the brass insert was what the seal met they would last longer.
Also lubrication of the seal may be an impact.
Re: Does anyone use this loop tester info required
The most important reason for the the EL test is to ensure the socket you are plugging the appliance into is correctly wired and earthed. This test should be done before you plug the machine back in.
This is to protect your self should there be an issue, engineers often have to multiple live test to ensure the machine is working correctly, you need to know that that socket is correctly earthed and wired properly.
Having found an issue with the socket you have the option to inform the customer of a potential problem. If there is a reversed live/neutral then this is a safety issue and this should be rectified. People often think this is not a big issue but depending on how the machine switches it feeds to components it could be a problem
If you find an earth fault such as no earth then again it’s a safety issue and should be rectified.If you get a high EL reading then this is where it’s grey, some if us will be trained spark’s and some won’t have a clue. The best way forward is if you have a reading above 200ohm regardless of the system you can notify the customer that there COULD be a problem and if they want to know more they should contact a sparky.
Those in the know can have a look of its a TT or supplier earth system and know if its normal or not but even if your in the know unless your part P and issuing a periodic report then you should never tell the customer there system is safe, you should just take the reading and move on.
Re: Aqualtis AQ113D697E constant pumping out
Yep that’s linear switch, measures actual water quantity via pressure rather than just a set level.
I would check the sump and pressure system then perform a reset as per HP method
Re: Ind. IS70C heater – which one? C00282396 or C00281561?
It’s the same heater just a different connector on it. The 1561 is the older connector and the other is the newer one. Depends on the age of the machine. However if you get the wrong one you can remove the pins from the plug and put them into the other one.
Re: Aqualtis AQ113D697E constant pumping out
Has it got the linear pressure switch ?
If so it thinks there is water in it. Iv seen these pump for about 45 minutes then throw F05. But if it was not left that long no error was shown.
Did you check the sump? One had a blockage (sock) in the sump. In the other a cable tie manage to float up into the pressure hose rite at the bottom.
Re: Indesit Dishwasher DIF04 Earth fault
Check the wiring to the lock its self behind the front panel,seen a few short through on the rod that runs across the lower end of the door. They rub through there
Re: Hotpoint aquarius WMF760 H20 light flashing.
Its either Pressure switch or board problem I am afrade,90{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} it’s the board not sure what board is in as iv not checked but I’d put a bet its the c00254298 or the 530 version as these seem to throw this error.
How fast is it showing the H20 error ? most of the ones i have seen show it just as it starts to fill or before it starts , if it is a water error due to slow filling or pressure switch it would fill for a time then give the error.
