Keysight 34460A/34461A/34465A/34470A Maximum Allowable Voltage change notice.

[wraper]

Hello folks - I wonder how this issue slipped through the hands of UL ... were they sleepy ?

I would be surprised if would not slip. Do they check every datasheet of every component and calculate/measure their voltage/current through them in every possible operating scenario? As said, this does not affect operation at all, and there is no safety risk.

[carl_lab]

Why not simply replace the faulty/weak component?
Only answer I could imagine is this component is the PCB...

[HighVoltage]

Failure risk very low, no safety risk
The products maintain their performance accuracy, and no failures have been observed up to 1000VDC.

Thank you Keysight for explaining some more details to us.
My own observation is also that I have NO problems at all and my 4 lab units meet specifications perfectly at 1000 V DC
I am inclined to continue to use my instruments at up to 1000 V DC

If I contact the service center, what can they offer for me?
 

[diyaudio]

Thanks to those on this EEV blog thread for the dialog about a standards compliance issue with Keysight Technologies’ 3446XA and 34470A digital multimeters. Your conversation reinforces Keysight’s commitment to address this issue to the satisfaction of our customers. We apologize if this has inconvenienced any of our customers, and acknowledge that this response is coming later than some would have hoped. 
 
What we have determined
While the product was initially rated at a maximum input value of 1000VDC/750VAC, this has been reduced to 600 VDC/440VAC to allow a component to operate within its rated values. There is no change in the Measurement Category II rating of 300V. The change in the maximum rated input voltage is to ensure the product meets requirements of the IEC61010 standards. Most importantly, there are no safety concerns related to this change.
 
Failure risk very low, no safety risk
The products maintain their performance accuracy, and no failures have been observed up to 1000VDC. While there is the possibility of component failure in using the products above 600 VDC/440VAC, there are no safety risks. Further, there have been no known component-related reliability failures since shipment of these products started in 2013.
 
Confidence in product reliability
These products continue to be covered by Keysight’s three-year standard warranty, and effective immediately, we will provide an additional one-year warranty extension to ensure customers can depend on our products.
 
Next steps
Keysight has begun redesigning the 3446XA and 34470A digital multimeters to reinstate the original maximum input ratings of 1000VDC/750VAC. We have set a goal to ship the redesigned products by December of 2017, and will make every effort to begin shipment sooner than that.
 
For more information about the steps Keysight is taking to address this issue, we have posted a service note on the company’s website. To view the service note, navigate to Keysight’s website, https://servicenotes.literature.keysight.com/litapp/SearchSN.do?method=openExternalSNSearch&prodNum= and type in product number 34461A-04. Any customers who require 1000VDC/750VAC testing capabilities can contact a Keysight Customer Contact Center and reference the service note number.

https://www.eevblog.com/forum/testgear/keysight-34401a/
So, last year I took my last earned cent to buy this instrument see above, How does this news bother me? It doesn't. What can you offer me as compensation? just throw me a FREE licence for benchvue, I would be grateful.
 
 
 
 

[plesa]

Thanks to those on this EEV blog thread for the dialog about a standards compliance issue with Keysight Technologies’ 3446XA and 34470A digital multimeters. Your conversation reinforces Keysight’s commitment to address this issue to the satisfaction of our customers. We apologize if this has inconvenienced any of our customers, and acknowledge that this response is coming later than some would have hoped. 
 
What we have determined
While the product was initially rated at a maximum input value of 1000VDC/750VAC, this has been reduced to 600 VDC/440VAC to allow a component to operate within its rated values. There is no change in the Measurement Category II rating of 300V. The change in the maximum rated input voltage is to ensure the product meets requirements of the IEC61010 standards. Most importantly, there are no safety concerns related to this change.
 
Failure risk very low, no safety risk
The products maintain their performance accuracy, and no failures have been observed up to 1000VDC. While there is the possibility of component failure in using the products above 600 VDC/440VAC, there are no safety risks. Further, there have been no known component-related reliability failures since shipment of these products started in 2013.
 
Confidence in product reliability
These products continue to be covered by Keysight’s three-year standard warranty, and effective immediately, we will provide an additional one-year warranty extension to ensure customers can depend on our products.
 
Next steps
Keysight has begun redesigning the 3446XA and 34470A digital multimeters to reinstate the original maximum input ratings of 1000VDC/750VAC. We have set a goal to ship the redesigned products by December of 2017, and will make every effort to begin shipment sooner than that.
 
For more information about the steps Keysight is taking to address this issue, we have posted a service note on the company’s website. To view the service note, navigate to Keysight’s website, https://servicenotes.literature.keysight.com/litapp/SearchSN.do?method=openExternalSNSearch&prodNum= and type in product number 34461A-04. Any customers who require 1000VDC/750VAC testing capabilities can contact a Keysight Customer Contact Center and reference the service note number.

https://www.eevblog.com/forum/testgear/keysight-34401a/
So, last year I took my last earned cent to buy this instrument see above, How does this news bother me? It doesn't. What can you offer me as compensation? just throw me a FREE licence for benchvue, I would be grateful.
 
 
 

You will receive free warranty:

Code: [Select]

Product that is currently out of warranty will have its warranty extended to 31st March 2018
Lot of companies will not publish this kind of note, unless there is reliability of safety risk.

1.There is no known reliability failure attributed to the component failure, since the start of product shipment in 2013.
2. The product maintains its performance accuracy and no failures where observed when units were tested up to 1000VDC. Further stress tests up to 1450VDC have not revealed any failure

In various vendors products you can see usage of components outside their operation conditions.
1450V test give me confidence that product is OK and we are talking more or less about formal note.

BTW: for logging there are much better alternatives than BenchVue

 

[SeanB]

I guess they are referring to the input posistor and fusible resistor, which probably is being run out of it's breaking range with over 600V applied, and the redesign is to simply use either a different part with higher ratings, or use 2 in series instead. Pretty much like almost every multimeter manufacturer, but here they want to prevent the input stage going foof if you apply 1kV to it in the high input impedance and it does not autorange fast enough and the resistors have to act as current limiting during the time autorange takes to operate.

[Cerebus]

I guess they are referring to the input posistor and fusible resistor,

If the design of the 3446x and 34470 are anything like their similar predecessors (34410 and the earlier 34401, for which there are schematics available) there are neither PTCs nor fusible resistors on the inputs. We're talking spark gaps, varistors and relays at the front followed by high impedances and diode clamps.

[SeanB]

Well then there is a resistor network or relay with relaxed spec, either they had a change of supplier for a nominally identical part, or the spec was quietly changed on them for those parts to derate it.

[LabSpokane]

The problem right now is that Keysight has nothing available even to replace these meters with (except, perhaps, 3458A but that would be a bit much to expect  ), so if you need to measure voltages over 600V DC and 440AC accurately, you have to look elsewhere or resort to some band-aids like an external voltage divider.

What's the big deal?
How many people need to measure between 600V and 1000V regularly in practice?

You're correct that most don't measure *nominal* values in those ranges.  What most of us need is for the meter to not be damaged by *transients* in that range.  If I knew what voltage I was going to read before I connected the meter, I wouldn't need a meter to begin with.  I will say that my standard practice is to use a handheld meter before connecting up my bench meter in order to blow up the least expensive device possible if I have a question.

The major problems for me with all of this mess are:

- This really feels like bait and switch.  We all bought meters based on their data sheet capabilities for not just what we wanted to do today, but for work we might do in the future.  We bought GENERAL PURPOSE tools, not CDMA site analyzers that we knew would become obsolete in a few years.

- Everyone with the affected meters just lost who-knows-how-much on the resale value based on the *perception* that these meters aren't that good - which isn't true of course - but perception becomes reality. 

- There's no shortage of us with multiple meters.  I have two and was thinking about getting another. 

As for the "solution," the extra year of warranty feels pretty underwhelming, and the MBA that thought that one up can stick it.  Affected customers deserve more.  Like 50% off on replacement DMMs for customers with registered units up to the number we already own.  The MBA won't like it, but that's the cost of a broken promise. 

[The Soulman]

I'm in no way affected by this as I don't have this meter but I'm stumped that there isn't any information released on the actual failure mode??
Is the accuracy (slightly??) affected??
Or is the input impedance going to rise or does it get lower??

Just two examples of realistic failure modes that might have keysight going "meh", but could have BIG impact on some costumers in the real world.

For keysight to save the day they have to be much more transparent.

[Someone]

The problem right now is that Keysight has nothing available even to replace these meters with (except, perhaps, 3458A but that would be a bit much to expect  ), so if you need to measure voltages over 600V DC and 440AC accurately, you have to look elsewhere or resort to some band-aids like an external voltage divider.

What's the big deal?
How many people need to measure between 600V and 1000V regularly in practice?

You're correct that most don't measure *nominal* values in those ranges.  What most of us need is for the meter to not be damaged by *transients* in that range.  If I knew what voltage I was going to read before I connected the meter, I wouldn't need a meter to begin with.  I will say that my standard practice is to use a handheld meter before connecting up my bench meter in order to blow up the least expensive device possible if I have a question.

Well we already received part of that answer:

While the product was initially rated at a maximum input value of 1000VDC/750VAC, this has been reduced to 600 VDC/440VAC to allow a component to operate within its rated values. There is no change in the Measurement Category II rating of 300V. The change in the maximum rated input voltage is to ensure the product meets requirements of the IEC61010 standards. Most importantly, there are no safety concerns related to this change.

So there is no safety problem and the transient protection rating remains the same. From all the information so far its a component being stressed beyond its manufacturers rating but hasn't caused mass failure in the field, or under synthetic testing within the limits described above (1450V withstand etc). Rather than just uprating the parts based on their field experience the spec has been lowered to meet the standards compliance requirements, its a paper pushing exercise and nothing to get worked up over.

[BravoV]

Simple noob question, what is the chance that this will ended up in law suit in the position favoring the plaintiff ?

I'm aware that Keysight has army of lawyers to defend them, but still ...

[Alex Nikitin]

Rather than just uprating the parts based on their field experience the spec has been lowered to meet the standards compliance requirements, its a paper pushing exercise and nothing to get worked up over.

Unfortunately, that paper pushing won't stop here. If a company is using these meters to measure voltages in 600-1000V DC and 440-750V AC ranges, and has to comply with the standards, it is now essentially prohibited from using these meters - for the same very reason Keysight has issued this change notice. Keysight asks customers in that situation to contact them:

Any customers who require 1000VDC/750VAC testing capabilities can contact a Keysight Customer Contact Center and reference the service note number.

However, as I understood it, they don't offer a solution, they only offer

more information about the steps Keysight is taking to address this issue

.

Cheers

Alex

[Dr. Frank]

I checked the latest IEC 61010-1 and IEC 6101-2-030, both are new versions (2017-01-01), replacing the old versions (2010-06-01).

Within these European standards, Safety Classes (e.g. II) and voltage ranges are defined:
The relevant ranges are (>300 <=600V) a.c. rms or dc and (>600 and <= 1000V) a.c. rms or dc.
These ranges require for example different clearances (isolation, jacks, PCB routes,..) and different constant or impulse voltages..

For example, the maximum transient overvoltage in CAT II, for 300..600V is 4kV, for 600..1000V it's 6kV.

The latter value has been increased (from 4kV) in the new revision of IEC 61010-2-030.

Also, the requirements for overvoltage limiting circuits (formerly these were explicitly named: varistors, spark gaps, ceramic capacitors, surge arresters) in the IEC 61010-1 has been increased from only 'suppressing such transients w/o overheating', to additionally 'continue to function properly after the test'.


So, here are my two conclusions:

The standard sets a.c. rms and dc values are defined as being equal in the same voltage ranges, which is not correct.
There is no explicit 440V a.c. range defined anywhere in these standards.

Instead, a.c. peak and d.c should be equivalent regarding transients and overvoltage protection.
Keysight corrected that fault by specifying 600V d.c. and 440V a.c. rms.


Although these standards in the past already defined the same classes and voltage limits, these two above mentioned changes (6kV and further functionality) may not have been given by the momentary design any more.
Most probably by reading the AN 34461A-04, there's a single component affected, maybe the spark tube, or maybe also the PCB design (clearances) does also not withstand these higher requirements.

These transients do not occur during normal use of these instruments in a laboratory / work bench, so that explains the statement, that there is no (or only small) risk in applying 1000Vdc / 750Vac.

I also bet, that older HP DMMs also will not fulfill this standard any more, also other DMM manufacturers will very probably not meet these requirements, if they would read these standards carefully and re-check their instruments.


Frank

[Someone]

Rather than just uprating the parts based on their field experience the spec has been lowered to meet the standards compliance requirements, its a paper pushing exercise and nothing to get worked up over.

Unfortunately, that paper pushing won't stop here. If a company is using these meters to measure voltages in 600-1000V DC and 440-750V AC ranges, and has to comply with the standards, it is now essentially prohibited from using these meters - for the same very reason Keysight has issued this change notice.

Which would be a vanishingly small number of users, the device is in cal for now so you're only stuck if you NEED the equipment to meet 61010 which would be a very unusual regulatory environment but feel free to provide examples which require continual compliance. If you're in that situation you can just use a divider probe and you're back off and running.

[HighVoltage]

Thank you Dr.Frank for your great explanation that makes perfect sense.

[Alex Nikitin]

Rather than just uprating the parts based on their field experience the spec has been lowered to meet the standards compliance requirements, its a paper pushing exercise and nothing to get worked up over.

Unfortunately, that paper pushing won't stop here. If a company is using these meters to measure voltages in 600-1000V DC and 440-750V AC ranges, and has to comply with the standards, it is now essentially prohibited from using these meters - for the same very reason Keysight has issued this change notice.

Which would be a vanishingly small number of users, the device is in cal for now so you're only stuck if you NEED the equipment to meet 61010 which would be a very unusual regulatory environment but feel free to provide examples which require continual compliance. If you're in that situation you can just use a divider probe and you're back off and running.

Which would be anyone working in a quality controlled environment.  I am not permitted to use in production a measuring equipment outside manufacturer's specifications. Obviously there are workarounds, but sometimes these are not easily applicable or desirable (i.e. a divider will introduce an additional uncertainty and needs calibration etc.).

Cheers

Alex

[Hensingler]

Confidence in product reliability
These products continue to be covered by Keysight’s three-year standard warranty, and effective immediately, we will provide an additional one-year warranty extension to ensure customers can depend on our products.

My 3.5 year old (with probably less than 400 power on hours) 34461A died 2 days ago - won't boot. I've been told there is no repair service just replace with new at full price although I am not sure I believe the keysight guy that told me that.

Reading this post maybe I am not quite as unlucky as I thought.

[wraper]

Confidence in product reliability
These products continue to be covered by Keysight’s three-year standard warranty, and effective immediately, we will provide an additional one-year warranty extension to ensure customers can depend on our products.

My 3.5 year old (with probably less than 400 power on hours) 34461A died 2 days ago - won't boot. I've been told there is no repair service just replace with new at full price although I am not sure I believe the keysight guy that told me that.

Reading this post maybe I am not quite an unlucky as I thought.

Then contact them again and mention service note 34461A-04, as your meter has (or will have) warranty extended to 31st March 2018

[nfmax]

I checked the latest IEC 61010-1 and IEC 6101-2-030, both are new versions (2017-01-01), replacing the old versions (2010-06-01).

So maybe the data sheet is changed to reflect the new version of the standard, and the instruments met & continue to meet the requirements of the previous version? Anything contractual should always reference the version of the standard.

[HighVoltage]

Any customers who require 1000VDC/750VAC testing capabilities can contact a Keysight Customer Contact Center and reference the service note number.

I contacted Keysight Germany today and had a very nice conversation but they could not offer anything new, except for:

1. There is no problem using my meters for up to 1000 V DC and my meters will all be covered by full warranty, even if something should go wrong.

2. The problem is related to two components on the PCB that are too close in proximity and because of this it requires a design change of the PCB.


 

[Tom45]

I checked the latest IEC 61010-1 and IEC 6101-2-030, both are new versions (2017-01-01), replacing the old versions (2010-06-01).

I wouldn't expect that meters would have to meet the new 2017-01-01 IEC standard that didn't exist when the meters were designed. Now that the standard has been made more strict a new design is necessary. As was said, mostly a paper pushing issue.

Was the updated IEC standard the result of any real problems in the field? Or was it just some desk jockey looking for something to change?

[GlowingGhoul]

I checked the latest IEC 61010-1 and IEC 6101-2-030, both are new versions (2017-01-01), replacing the old versions (2010-06-01).

I wouldn't expect that meters would have to meet the new 2017-01-01 IEC standard that didn't exist when the meters were designed. Now that the standard has been made more strict a new design is necessary. As was said, mostly a paper pushing issue.

Was the updated IEC standard the result of any real problems in the field? Or was it just some desk jockey looking for something to change?

If this change were simply the result of applying a new standard, they would simply say that the equipment meets specs under the standard in force at the time of sale.

[Tom45]

If this change were simply the result of applying a new standard, they would simply say that the equipment meets specs under the standard in force at the time of sale.

But that would mean that they can't sell the meters after the first of this year. So they would need to update the design to keep selling them. Which is what they are apparently doing.

It looks like somebody at Keysight wasn't paying attention and didn't notice the change in the standards. Keysight should have come out with an updated design before the new standard went into effect. Not months later as is apparently the case.

[GlowingGhoul]

If this change were simply the result of applying a new standard, they would simply say that the equipment meets specs under the standard in force at the time of sale.

But that would mean that they can't sell the meters after the first of this year. So they would need to update the design to keep selling them. Which is what they are apparently doing.

It looks like somebody at Keysight wasn't paying attention and didn't notice the change in the standards. Keysight should have come out with an updated design before the new standard went into effect. Not months later as is apparently the case.

It's really straightforward in my opinion:

Due to an error on Keysight's part, this series of DMM'a are not capable of providing the capabilities it was represented to have at the time of sale.

They may suggest (wink wink) it's ok to use the unit out of (the updated) spec, and not to worry because you have an additional 12 months of warranty. This is hardly reassuring and I don't think too many users will be comfortable exceeding specs.

Whether you use the high range of voltages or not, you now own a DMM that is not what it purported to be. It will be worth less at resale. Compensation is in order. I mean, not even an updated sticker for the front panel?