Vaillant ecoTEC plus 428 f27, f64 & CON error

[DP]

This is not relevant to the thread topic of repairing boilers because it is the norm to replace and not to repair PCBs and fans etc.

Thank you for posting above comment. We are not using high frequencies other than in SMP supplies so losses you refer to would be important when such frequencies are needing replacement capacitors. Capacitors (new ) fed 100hz rectified AC pulse and low current will hardly succumb to miniscule losses

Simple example would be a lighting cable supplying power to a lamp
Same cable running a 10Kw shower would now result in cable loss so shower gets 240 volts less the voltage dropped by cable

ESR losses need considering when frequency is high e.g. 10khz, current is heavy so ESR will have voltage drop. This happens when capacitor is connected to AC waveform. High ESR under such conditions result in heat being generated hence some capacitors balloon indicating failure

Boiler circuits are mostly DC or rectified AC and current is insignificant. SMP supplies would be exception to the rule ( SIMSI board etc) where high frequency is used and current can be high. Ambient temperature is also a factor

Tony you should read up more on the subject as there are other losses in the capacitor you fail to mention.

 

[Agile]

I suppose DP would say that he can tell by looking at a capacitor that the ESR is high!

 

[DP]

In picture posted, meter and visual alone would give good enough indication
Looking at the components is enough to suggest what the setup is.
I am suggesting ESR is not something I would feel is important on this particular PCB for the big capacitor

Tony I think you need to study the topic 'losses in capacitors' before speculating what I can or cannot do.

I thought we has put the ESR baby to bed!!

 

[ianmcd]

Did you ever meet gandalf for your enlightenment ?

 

[Agile]

In picture posted, meter and visual alone would give good enough indication
Looking at the components is enough to suggest what the setup is.

In this particular instance I already knew what the problem component was just by listening to the boiler even before I took the case off !

 

[DP]

In this particular instance I already knew what the problem component was just by listening to the boiler even before I took the case off !

So, did you use the ESR meter then?

 

[Agile]

I may remove it tomorrow and measure the ESR of the replacement as well as the failed one.

 

[DP]

Any progress on testing front Tony?
Do not forget to post picture of the cap you removed showing the value and measured capacitance as well as the ESR value
Are you suggesting capacitor is goosed and relays were chattering?
Looking at the components on the board in the picture, can you explain the function of components left of transformer?
Going quiet is admission of defeat.

 

[Agile]

100 hz ripple on 24v rail causes the mod coil to buzz at 100 hz.

Surely you don't need me to tell you there is a diode bridge made up of 1N4006 diodes as well as a 24v regulator above.

 

[Steelmasons]

Last night an electronics engineer friend called me and I took the opportunity to ask him if he had an ESR meter and how much he used it. He agreed that it was important to measure ESR in some applications and said that a while ago he was repairing TVs for a few months in between his normal defence design jobs and used an ESR meter daily.

This is not relevant to the thread topic of repairing boilers because it is the norm to replace and not to repair PCBs and fans etc.

Tony

Considering your above post is not relevant to the thread topic then surley you won't mind answering the question DP put to you in the other thread?

 

[DP]

100 hz ripple on 24v rail causes the mod coil to buzz at 100 hz.

Surely you don't need me to tell you there is a diode bridge made up of 1N4006 diodes as well as a 24v regulator above.

Oh really Tony!!!!
Are you sure 1N4006?
24 volt regulator with numbers L7812?
How can you have 100 Hz ripple on rectified ac supply. You have raw Rectified AC. Hz is what old cycles per second was. Bridge rectifier will result in 100 pulses per second, not 100 cycles per second. Take it you have not come across rectified ac powering relays etc that do not buzz.
Too many questions. I will await your response to tell me what I am missing

I think you need to get some electronic education under your belt instead of posting non information or need to get new glasses

You have responded with a post that is based on speculation and assumption alone
What part of your post is one to take seriously I ask you?

 

[Steelmasons]

He fails miserably at googling , much the same working on boilers.

 

[Agile]

If the capacitor was in good condition then you would have nice smoothed DC.

When the capacitor value is low then you get DC with a 100 Hz ripple.

Not normal to power relays with unsmoothed AC but if it is needed the a diode is fitted across the solenoid to take advantage of it's inductance to prevent it buzzing.

 

[DP]

Again you are reaching
The diode in the picture is there to protect the transistor I would imagine. I can confirm yes or no if you tell me what the pcb is. Can find a pcb to support my claim too

I would have checked capacitor value using by Fluke to check capacitance. You meanwhile would be reaching for ECR meter and cannot accept in circuit you show in the picture, visual indication would be a trigger point to be confirmed with a meter like Fluke 116. You have yet to sustantiate your assertion. This is because you perhaps lack cicuit theory, understanding components or component utilisation in circuits. I on the other hand will only say what I have experienced in practice, a fact you cannot take on board. You keep coming back with information that lacks substance

Keep digging, you will end up in Darwin before long

 

[DP]

He fails miserably at googling , much the same working on boilers.

Steel, Tony will be better checking what is being said by members instead of arguing that he is right and all others wrong

Cannot believe some of the things Tony is posting. Even the guys who are quite laid back and placid with oodles of knowledge, are waking up to silly unbelievable stuff that is being posted by Tony.

Many years ag I use to believe I was the best in rptask I carried out until one guy pointed that my work also had failures. I now am willing to look back and check/ apologise even/ admit I do make mistakes/ not praise myself/ am humbled when I get praised by my clients etc

For example the last response is based on assumptions, nothing factual.
No mention of regulator that he says is 24 volts is in fact 12
Quotes diode spec that is for 800 volts when transformer output, if tony is to be believed, is 24 volt ac.
No mention of capacitor value or how he checked and rectified the fault.

I give up.