Electrical Safety in SR

[Tyler Ward]

TLDR: Currently we aren't testing our electrical equipment, therefore
we don't know the equipment we are shipping is in a safe state to be
used, this should be fixed.

We are required as part of our duty of care to ensure that the
equipment we are issuing to schools and using at events is safe. While
we are doing well in many areas we are currently lacking in electrical
equipment safety.

Proposals

Require all electrical equipment shipped to schools to be tested
before kit shipping.
(This will be chargers and power supplies, as well as the chargers for
the tablets)

For low cost chargers/supplies/4ways perform a tear down on one of
each type to ensure they actually comply with UK safety
requirements[2,3,4,5] and that we feel that they are suitable.
(Useful points: A competitors phone charger went bang at the
competition and several of the 4 ways have shattered exposing live
mains parts)

Test all SR events kit/tools/extension leads/RCD's before each major
event when they will be used (e.g. competition and smalpiece and
kickstart)


How to achieve the testing
There are several options here:

1. Buy a PAT tester+required accessories. (this will allow us to test
equipment whenever it is needed)
2. Pay for an outside company to test our equipment (Based on reports
from events teams at SUSU and elsewhere this is not recommended as the
majority of these companies are only expecting office style equipment)
3. Attempt to get them pat tested by branch university's (Although
Southampton have done this in the past I see this as unlikely now
given the volume of kit that would need doing).

Tyler


[1] http://www.hse.gov.uk/pubns/priced/hsg107.pdf
[2] http://www.bbc.co.uk/news/uk-27515446
[3] http://www.righto.com/2014/05/a-look-inside-ipad-chargers-pricey.html
[4] http://www.bs1363.org.uk/
[5] http://www.electricalsafetyfirst.org.uk/mediafile/100015224/Chargers.pdf

[Alistair Lynn]

Hi Tyler-

> TLDR: Currently we aren't testing our electrical equipment, therefore
> we don't know the equipment we are shipping is in a safe state to be
> used, this should be fixed.

> 1. Buy a PAT tester+required accessories. (this will allow us to test
> equipment whenever it is needed)
> 2. Pay for an outside company to test our equipment (Based on reports
> from events teams at SUSU and elsewhere this is not recommended as the
> majority of these companies are only expecting office style equipment)

Can you give us some idea of the relative costs of these two?

Alistair

[Tyler Ward]

External pat testing is usually between £0.5 and £1 per item

A quick count gives of the inventory gives us
83 battery charger power supplies and mains cables (these might be
charged separately!)
23 inventoried 4 ways (I have seen several that aren't inventoried yet
so there are more of these)
20 RCD's (although I am certain we have/had more)
6 monitors and cables (these might be charged separately)
6 beagle board supplies.
several network switches and other misc mains kit in the vault (i am
guessing about 20 devices if i remember correctly)

I know we are also getting
~80ish tablet chargers

There are probably more devices that I have missed

This gives us over 220 devices which is between £110 and £220 every
time we need to test them.
many of these will need testing several times a year which will put
the cost up further.

A entry level pat tester (Seaward 250 as recommended by David Oakley
in ECS) that will do what we want (Class1, Class2, Extension leads and
RCDS) can be bought for about ~£300 (contract prince on
onecall.farnell (exvat)), but shouldn't cost more than about £400.
There will also be some other small costs on top of this such as
buying stickers to mark tested devices/required adapters, a logbook to
record what we have tested ect.

Tyler

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[Murray Colpman]

On 03/10/14 17:36, Tyler Ward wrote:
> A entry level pat tester (Seaward 250 as recommended by David Oakley
> in ECS) that will do what we want (Class1, Class2, Extension leads and
> RCDS) can be bought for about ~£300 (contract prince on
> onecall.farnell (exvat)), but shouldn't cost more than about £400.
> There will also be some other small costs on top of this such as
> buying stickers to mark tested devices/required adapters, a logbook to
> record what we have tested ect.

It's worth pointing out explicitly, if anyone is interested, that there
are no specific requirements for qualifications to perform PAT testing.
You only need to be "competent", which apparently is defined as 'A
person possessing sufficient technical knowledge or experience to be
capable of ensuring that injury is prevented'. Therefore assuming we can
say this about at least one person in SR, there wouldn't be any costs
for training, etc.

Murray Colpman.

[Peter Law]

Tyler wrote:
>> A entry level pat tester (Seaward 250 as recommended by David Oakley
>> in ECS) that will do what we want (Class1, Class2, Extension leads and
>> RCDS) can be bought for about ~£300 (contract prince on
>> onecall.farnell (exvat)), but shouldn't cost more than about £400.

I think that this is the route we should take. Even if we occasionally
get things done by an external company, being able to just do them
ourselves is probably worthwhile.

>> There will also be some other small costs on top of this such as
>> buying stickers to mark tested devices/required adapters, a logbook to
>> record what we have tested ect.

These feel redundant -- surely this information can be put into the inventory?

Murray wrote:
> It's worth pointing out explicitly, if anyone is interested, that there
> are no specific requirements for qualifications to perform PAT testing.
> You only need to be "competent", which apparently is defined as 'A
> person possessing sufficient technical knowledge or experience to be
> capable of ensuring that injury is prevented'. Therefore assuming we can
> say this about at least one person in SR, there wouldn't be any costs
> for training, etc.

Indeed. I believe that Tom B has PAT tested things in the past, and
may be able to inject further info.

A quick googling lead to the following HSE page, which appears to
confirm the above:
http://www.hse.gov.uk/electricity/faq-portable-appliance-testing.htm

Peter

[Harry Cutts]

Hi,

On Friday, 3 October 2014 17:36:56 UTC+1, scorpia wrote:

many of these will need testing several times a year which will put the cost up further.

For reference, "Maintaining Portable Electrical Equipment" [0], a booklet from the HSE, contains a table of *suggested* test and inspection frequencies (page 17). It also emphasises (page 16, "Frequency of Examinations") that "Determining the frequency of inspection and testing is a matter of judgement by the dutyholder, and should be based on an assessment of risk."

Personally, I don't think that any of our equipment needs testing more frequently than once a year. Of the stuff we ship (charging equipment), the suggested test frequency is 1-4 years. For the events equipment, I'd guess that the HSE guide assumes constant (or at least, very frequent) use, whereas our equipment is used for a maximum of one month per year (including Smallpeice summer schools). We may wish to perform "Formal visual inspections" on events equipment before every major event, but I think full testing would be unnecessary.

Harry Cutts

[0] http://www.hse.gov.uk/pubns/priced/hsg107.pdf

[Jeremy Morse]

Hi,

On 03/10/14 09:07, Tyler Ward wrote:
> TLDR: Currently we aren't testing our electrical equipment, therefore
> we don't know the equipment we are shipping is in a safe state to be
> used, this should be fixed.
>
> We are required as part of our duty of care to ensure that the
> equipment we are issuing to schools and using at events is safe. While
> we are doing well in many areas we are currently lacking in electrical
> equipment safety.

Electrical safety is indeed an extremely important part of what we do.
However, what we give to schools does not require testing.

The battery chargers themselves are low voltage. The transformer boxes
are class 2 double-insulated devices. The power cables that plug into
them are figure-8 IEC leads that don't have a ground wire. None of these
things require testing. The HSE guidelines [0] for low risk environments
[1] recommends no testing and a visual inspection once every two to four
years.

I can't see the tablets being any different, although I don't have one
to hand.

> For low cost chargers/supplies/4ways perform a tear down on one of
> each type to ensure they actually comply with UK safety
> requirements[2,3,4,5] and that we feel that they are suitable.
> (Useful points: A competitors phone charger went bang at the
> competition and several of the 4 ways have shattered exposing live
> mains parts)

We should observe whether they have a CE mark, which ensures they
conform with regulations. One of the reasons these kinds of markings for
standard conformance exist is to avoid customers having to rate every
single product they use.

> Test all SR events kit/tools/extension leads/RCD's before each major
> event when they will be used (e.g. competition and smalpiece and
> kickstart)

3rd parties should not be using our tools, blueshirts is a slightly
different matter. Extension leads and RCDs are much more easily handled
by adding them to the electrical equipment hire: we save time, effort,
initial investment and storage costs as a result. In all cases this can
safely be discussed after Kickstart.

[0] http://www.hse.gov.uk/pubns/indg236.pdf
[1] I.E., ones where you are unlikely to have a mountain of swarf poured
into equipment

--
Thanks,
Jeremy

[Andy Busse]

Hi,

I ought to mention that Tyler asked me about this off-line a couple of
weeks ago and some of the below comes as a result of having a word with
our lead SAP(E) [0].

How we manage Electrical Safety in SR can come down under 3 things:
1) Electrical Safety of the battery-powered modular electronic kits
2) Electrical Safety of the mains-powered equipment shipped to schools
3) Electrical Safety at events

For 1), we're fine - I can elaborate on what guidelines we work to if
you want. The way we manage safety of the modular electronic kit is
sufficient - the cases are designed such that getting at electrical
hazards is sufficiently difficult. It might be worth stressing that live
working on uncased elec kit should only be done by people who know what
they're doing, or are being supervised by those who do.
For 2) and 3), we're not:

* PAT Testing *

On 03/10/2014 09:07, Tyler Ward wrote:
> Proposals
>
> Require all electrical equipment shipped to schools to be tested
> before kit shipping.
> (This will be chargers and power supplies, as well as the chargers for
> the tablets)
>
> For low cost chargers/supplies/4ways perform a tear down on one of
> each type to ensure they actually comply with UK safety
> requirements[2,3,4,5] and that we feel that they are suitable.
> (Useful points: A competitors phone charger went bang at the
> competition and several of the 4 ways have shattered exposing live
> mains parts)
>
> Test all SR events kit/tools/extension leads/RCD's before each major
> event when they will be used (e.g. competition and smalpiece and
> kickstart)

I absolutely endorse this. The testing frequency is basically what's in
the 17th Edition, endorsed in places by HSE and BSI as linked to
elsewhere in this thread. (Actually, looking at the 17th Ed, I recommend
we treat the competition like a construction site, and check equipment
twice daily. It gets kicked around a fair bit.)

I also endorse the fact that we need to tear down chargers and 4-ways.
We're responsible for ensuring kit we send to schools is safe, and just
because a manufacturer has put a CE mark on something doesn't mean it
is. Heck, the chargers are sold for £8.43, which means it's either a
great deal or corners are being cut somewhere. I avoided using these on
helpdesk because of the cheap case, the lack of a screen and the fact
the charging rate is set with a crude pot. We also need to think whether
cable tying the banana leads to the case is the safest way of mitigating
a battery short circuit.

4-ways are an interesting thing - I was shown an example of where a
robustly designed one had caught fire when a convection heater was
plugged in, due to loose internal wiring. The ones we have are
definitely not designed for use in the environment we put them in. I
recommend we buy, or hire some metal-cased ones (like we had on
helpdesk) designed for events use.

> How to achieve the testing
> There are several options here:
>
> 1. Buy a PAT tester+required accessories. (this will allow us to test
> equipment whenever it is needed)

This is probably the best way of achieving this. I think Murray made a
comment about there being no particular need for the person doing PAT
testing to be trained, but to be competent. While this is true, we need
to be convinced that a bunch of lawyers (specifically the lawyers our
liability insurers choose) will accept this. The course (C&G 2377) costs
£200.

We might also want to consider inspecting the equipment plugged into our
mains network by competitors - do we want to risk cheap chargers
catching fire, or tripping out parts of the network?

Thanks,
Andy

[0] "Senior Authorised Person (Electrical)". Google it, but tl;dr
responsible for electrical safety policy on our site.

[Tyler Ward]

On 3 October 2014 20:10, Jeremy Morse <jmo...@studentrobotics.org> wrote:
> Hi,
>
> On 03/10/14 09:07, Tyler Ward wrote:
>> TLDR: Currently we aren't testing our electrical equipment, therefore
>> we don't know the equipment we are shipping is in a safe state to be
>> used, this should be fixed.
>>
>> We are required as part of our duty of care to ensure that the
>> equipment we are issuing to schools and using at events is safe. While
>> we are doing well in many areas we are currently lacking in electrical
>> equipment safety.
>
> Electrical safety is indeed an extremely important part of what we do.
> However, what we give to schools does not require testing.
>
> The battery chargers themselves are low voltage. The transformer boxes
> are class 2 double-insulated devices. The power cables that plug into
> them are figure-8 IEC leads that don't have a ground wire. None of these
> things require testing. The HSE guidelines [0] for low risk environments
> [1] recommends no testing and a visual inspection once every two to four
> years.
>
> I can't see the tablets being any different, although I don't have one
> to hand.

Due to the fact that we issue kit to other parties we should consider
using the guidance for Equipment Hire as that is what we are doing.
This requires a Combined inspection and test before each kit issue.
In addition as the equipment is moved regally by teams we most likely
don't meet the moved occasionally requirement of the 1-4 year test
period.

In addition it should be remembered that it is a requirement of any
Southampton room booking for kick start,tech-days and doings
(including those where we test and pack the kit) that all equipment
has received a safety test in the last 12 months. this is likely the
case for other venues as well.

>
>> For low cost chargers/supplies/4ways perform a tear down on one of
>> each type to ensure they actually comply with UK safety
>> requirements[2,3,4,5] and that we feel that they are suitable.
>> (Useful points: A competitors phone charger went bang at the
>> competition and several of the 4 ways have shattered exposing live
>> mains parts)
>
> We should observe whether they have a CE mark, which ensures they
> conform with regulations. One of the reasons these kinds of markings for
> standard conformance exist is to avoid customers having to rate every
> single product they use.

Unfortunately the unsafe versions coming into the UK also have these
marks although they have no chance of meeting the requirements. In
addition it may be perfectly compliant with the Requirements but not
suited to use in the events industry.

>
>> Test all SR events kit/tools/extension leads/RCD's before each major
>> event when they will be used (e.g. competition and smalpiece and
>> kickstart)
>
> 3rd parties should not be using our tools, blueshirts is a slightly
> different matter. Extension leads and RCDs are much more easily handled
> by adding them to the electrical equipment hire: we save time, effort,
> initial investment and storage costs as a result. In all cases this can
> safely be discussed after Kickstart.

We are still required to test kit that is used by Blueshirts the same
as an employer is required to the the kit used by their staff.

>> There will also be some other small costs on top of this such as
>> buying stickers to mark tested devices/required adapters, a logbook to
>> record what we have tested ect.
>
>These feel redundant -- surely this information can be put into the inventory?

Putting this information into the inventory is a good idea.
The purpose of the sticker is to make it immediately obvious to any
user that the equipment has been tested.
The logbook is useful as we can record pat tests that have been
carried out for items without needing to be able to have immediate
access to the inventory or needing to find the items afterwards to
confirm that we did them.

[Jeremy Morse]

Hi,

The subsequent replies here don't seem to have addressed the part where
the kit we ship at schools does not require testing. They are safe by
design. Hire companies are expected to test all equipment as they are
not able to control for the risks faced by their equipment -- however we
know that our kit is only ever used in an office environment. Any
concerns we might have can be fixed with the following sentence:
"Teachers will supervise all battery charging".

I have never heard of a business stripping down a laptop transformer to
check that it qualifies to bear the CE mark (UoB and UoS certainly
don't). I also don't believe anyone present here is qualified to reverse
engineer such a design and evaluate it. The most relevant question is:
Do we have reason to believe that HobbyKing or Endatech, both large and
non-new businesses that have a presence in the UK, would supply us with
defective equipment?

The chargers do not bear a CE mark at all, because they are low voltage
and according to the guidelines I cited require neither testing nor
inspection, at all.

Andy Wrote:
> We also need to think whether cable tying the banana leads to the
> case is the safest way of mitigating a battery short circuit.

This is much more relevant, as there's a foreseeable and feasible risk
that a competitor screws this up (I've seen a blueshirt do it too,
modulo the cable tie). As it's not dependant on mains voltage being
present however, it should probably go in a different thread.

Andy Wrote:
> 4-ways are an interesting thing - I was shown an example of where a
> robustly designed one had caught fire when a convection heater was
> plugged in, due to loose internal wiring. The ones we have are
> definitely not designed for use in the environment we put them in. I
> recommend we buy, or hire some metal-cased ones (like we had on
> helpdesk) designed for events use.

I entirely agree here, hiring equipment suited to use at the competition
is the best solution.

> We might also want to consider inspecting the equipment plugged into
> our mains network by competitors - do we want to risk cheap chargers
> catching fire, or tripping out parts of the network?

This is solved by not permitting them to charge in pits, which we
enforce.

--
Thanks,
Jeremy

[Murray Colpman]

On 08/10/14 23:58, Jeremy Morse wrote:
> however we
> know that our kit is only ever used in an office environment

It's really not. The competition and school DT labs spring immediately
to mind.

An ECS health and safety guy happened to meet us in the vault today and
give us a little advice. He suggested that most schools would probably
have a policy that all kit coming in should be PAT tested. Clearly if
they do, it isn't particularly enforced, but it'd still be a nice thing
to do. Especially since he mentioned we could talk to a particular
person in ECS (Harry has the details) who would probably do it for us.

> The chargers do not bear a CE mark at all, because they are low voltage
> and according to the guidelines I cited require neither testing nor
> inspection, at all.

What about the charger power supplies? They look exactly like a zero budget, zero quality cheapy crappy Chinese netbook charger I bought once - at least the ones for the new (non-IMAX) chargers. I haven't checked whether they are CE marked or not, but if they were given how terrible my netbook charger was I'm not sure I'd trust it to be genuine.

> This is solved by not permitting them to charge in pits, which we
> enforce.

"Chargers" here referred to the mobile phone charger that exploded at the previous competition, I expect. I believe they are allowed to charge those in pits.


Murray.

[Jeremy Morse]

Hi,

On 09/10/14 00:08, Murray Colpman wrote:
> It's really not. The competition and school DT labs spring immediately
> to mind.

I refer you to the final sentence in that paragraph

> An ECS health and safety guy happened to meet us in the vault today and
> give us a little advice. He suggested that most schools would probably
> have a policy that all kit coming in should be PAT tested. Clearly if
> they do, it isn't particularly enforced, but it'd still be a nice thing
> to do. Especially since he mentioned we could talk to a particular
> person in ECS (Harry has the details) who would probably do it for us.

The person will be Danny most likely; and what the chap was probably
saying was that schools require that incoming kit be /tested by _their_
contractors/. Outsourcing that problem to schools is entirely reasonable.

> What about the charger power supplies? They look exactly like a zero
> budget, zero quality cheapy crappy Chinese netbook charger I bought
> once - at least the ones for the new (non-IMAX) chargers. I haven't
> checked whether they are CE marked or not, but if they were given how
> terrible my netbook charger was I'm not sure I'd trust it to be
> genuine.

I refer you to the second paragraph of my email; when I say laptop
transformer, I mean it in relation to the transformers that the chargers
have.

> "Chargers" here referred to the mobile phone charger that exploded at
> the previous competition, I expect. I believe they are allowed to
> charge those in pits.

3rd party tools are strictly not our problem.

--
Thanks,
Jeremy

[Murray Colpman]

> I refer you to the final sentence in that paragraph

Teacher supervision != using in an office environment. Unless we gave
specific instructions not to use in labs (which, I should point out, is
where a lot of schools carry out their meetings).

On 09/10/14 00:14, Jeremy Morse wrote:
> I refer you to the second paragraph of my email; when I say laptop
> transformer, I mean it in relation to the transformers that the chargers
> have.

Apologies. I will, however, say that I wouldn't put it past companies on
the order of HobbyKing to sell cheap chinese knock-offs with their
stuff. I've heard of a LOT of things from various relatively
high-profile sources coming with power supplies like these. The
University, on the other hand, probably buys their laptops from a much
more trusted source. I would not expect them to tear down laptop power
supplies because they are probably manufactured by or with the thorough
inspection of the laptop manufacturer as opposed to a virtually-nameless
Chinese company where some distributor happened to bundle them in the
same box as a charger. Given the cost of these chargers, I think it
would be a shame not to take up the opportunity to look inside one for
at least a basic sanity check.

I agree with you that 3rd party things are not our problem - I was just
pointing out what was meant by the original statement.

Re your schools

Murray.

[Andy Busse]

This stuff reminds me - our risk assessments are probably due for review
now. Do you want me to take a look again? (Probably ought to be another
thread)

On 08/10/2014 23:58, Jeremy Morse wrote:
> Hi,
>
> The subsequent replies here don't seem to have addressed the part where
> the kit we ship at schools does not require testing. They are safe by
> design. Hire companies are expected to test all equipment as they are
> not able to control for the risks faced by their equipment -- however we
> know that our kit is only ever used in an office environment. Any
> concerns we might have can be fixed with the following sentence:
> "Teachers will supervise all battery charging".
>
> I have never heard of a business stripping down a laptop transformer to
> check that it qualifies to bear the CE mark (UoB and UoS certainly
> don't). I also don't believe anyone present here is qualified to reverse
> engineer such a design and evaluate it. The most relevant question is:
> Do we have reason to believe that HobbyKing or Endatech, both large and
> non-new businesses that have a presence in the UK, would supply us with
> defective equipment?

The tests performed by HSE on the wall warts were all sourced from the
high street (I was told Argos & Tesco, a couple may have come from
Amazon/eBay). Are you reasonably convinced that at the price we get them
for, they're safe for the environments they're going in to.

Also, I didn't suggest we tear apart the brick supplies, but some of the
other third-party kit. (In fact, for the brick supplies, it's probably
just worth considering these are designed for use in office environments
and will almost certainly be used in workshops - are they rugged enough?
Very probably).

The principle applied in the nuclear world is to make all risks "As Low
As Reasonably Practicable", and this is what I'm suggesting here. It
might not be worth our while fully testing the transformers, but what
can we do reasonably cheaply, quickly and easily, with kit we can get
our hands on?

I'm not trying to force through things that will be a pain in the arse
to do or cost us a ton of money, this is what "Reasonably practicable"
means, and the suggestions are almost intended as questions. If
anything, we ought to have this discussion after every competition, and
when new kit is introduced (and consider all risks, not just electrical).

* PAT test and visually inspect chargers before they leaves us, so we're
convinced the equipment was safe before it gets handed over. If we can
test again at the competition when we take the chargers back, before
plugging in to helpdesk, even better. ("Visually inspect" = check for
damage to cables, plug, transformer pack, output lead, strain relief, etc.)
* Charge batteries at full charge rate (i.e as far as the pot will go)
and check case temperature.
* Take the battery charger case off and poke around, Dave Jones style.
Like I said, I personally don't like the cheap feel of them (I know
others share this opinion), and a quick analysis might tell us where
corners have been cut, whether it's really safe, and also whether these
might be reducing battery life. Is £30 lost and a doing's worth of
effort to learn a little more about how these work worth it?

Anyone for any more?

> The chargers do not bear a CE mark at all, because they are low voltage
> and according to the guidelines I cited require neither testing nor
> inspection, at all.

See above. Just because something might not be required by law doesn't
mean we shouldn't do it if it's reasonably practicable and mitigates
risks. We test and inspect elec kits before shipping, then why not
chargers too, if it's easy to do?

> Andy Wrote:
>> We also need to think whether cable tying the banana leads to the
>> case is the safest way of mitigating a battery short circuit.
> This is much more relevant, as there's a foreseeable and feasible risk
> that a competitor screws this up (I've seen a blueshirt do it too,
> modulo the cable tie). As it's not dependant on mains voltage being
> present however, it should probably go in a different thread.

Yeah, Tyler asked me about Electrical Hazards, which includes ELV and
stored charge. This is probably the biggest hazard.

>> We might also want to consider inspecting the equipment plugged into
>> our mains network by competitors - do we want to risk cheap chargers
>> catching fire, or tripping out parts of the network?
> This is solved by not permitting them to charge in pits, which we
> enforce.

Here, I didn't mean chargers specifically but meant as a minimum, having
a safety face wandering around checking what's been plugged in to our
network, and that the pit areas are generally safe (i.e. trip hazards
from stuff attached to mains, anything obviously dodgy being plugged in,
etc.).

It was also a question to whether it's feasible to enforce a "only PAT
tested equipment our network" rule, and providing a PAT testing service
at the competition.

Thanks,
Andy