today we're looking at isolation switches and switch fuses from Lewden Palazzoli
Presented by Gary Hayers GSH electrical and Gordon Routledge
fantastic day I've got the best position here i can just lean against this switch here because
gary is going to be answering all the technical parts of this video hence the glasses are on
from the start and we're going to be looking at on load isolators what do you think we mean
by on load isolators gordon uh well i'm assuming that's a switch or isolator where you can actually
disconnect the load with it fully powered up okay without reading that in the instructions
how do you think you're going to be made aware of that on devices that have already been installed
oh i don't know you tell me what am i looking for all right okay i've got the instructions
in front of me here so if i just pop it up here we see it on the screen now so let's look at the
symbols there underneath two pole three pole and four pole switch that's the symbol for an on load
isolator okay so that's what we're looking for we'll explore it a little bit further in BS7671
in a minute can you put it on any of these well obviously we're not gonna these instructions okay
might be if we have a look at them in the first place we won't be looking at them when they've
been lost after the project's been installed so where can i see that on here right so i'm picking
this one up here gary there's the there's the front ah so there's the symbol there that's the
one so it's the it's the switch with a sort of big a dot and a line across it absolutely is so
yeah that's the on load isolator symbol you wanna try one more for me okay i'll pull it out of this
one here right so here's our this plastic-based isolators on the label there yes it is yeah and
you'll often see that symbol as well on consumer units as well for the main switch on a consumer
unit it's really small but you're right yes you will so what does that mean so let's explore
what functions these switches have from BS7671 so if we look here at this table here which is table
537.4 it's over two pages i've got a segment of it here if you look down that isolating switch
you can see the bsen number and that bsem number is 60947-3 the important three columns for me
gordon are the following isolation yes emergency switching yes functional switching yes so what
do you think we mean by functional switching uh function you can switch it on off and it's normal
operation like a light switch absolutely emergency switching emergency switch i need to switch it off
quickly because someone has been dragged into a machine and i need to stop that happening
and absolutely and isolation I'm going to be working on the machine possibly doing some
mechanical maintenance or electrical maintenance absolutely so these switches in front of us offer
all three of those functions and we know that so if i look back into my instructions here i
pick up the number once again so we go back into here you can see i've got that number 60947 dash
so we know it for performs all three of those operations gordon what else do you want to know
about this uh well let's have a thing isolate us why they all was red and yellow or the tender
always be red and yellow they look nice okay that would be too easy wouldn't it so of course because
these can be used for emergency isolation the regulations say the preferred colours are what
do you reckon the preferred colours are gordon let's have a guess here i'm thinking possibly
red for the switch but and then yellow surrounding it let's have a look so if we go into bs7671 and
look in the section here for devices for emergency switching okay and we look down at the regulation
537.3.3.5 the preferred colors are red with a contrasting background of yellow so that's why we
see it so many times out there in industry these colors because it can also be used as those three
functions one of them was for emergency switching gordon okay so to me i can see it across the room
and i know where i'm running to is you're being dragged into the machine probably the opposite
direction yeah from the switch yes yeah we get that one so so let's start look at what we've got
here so these are not just a switch are obviously an emergency switch a functional switch and also
can perform isolation okay so i guess next we need to have a look at the things the electrician
really cares about and actually what's the product like to install and some of those other important
features so the electrical contractor gordon what are you looking for in this range of isolators
from lewd and palozzoli okay so the first thing i'm thinking about is the current rating do they
have the span of current ratings that are going to encounter in the installation so lots of people
have sort of low rate low amperage ratings it's when you get to those higher amperage ratings
and some ranges start to struggle but thankfully this range from luden goes all the way up to 125
and the range we've got on the table here even bigger when you look at some of the bigger units
we've got behind us so yeah that's covered nothing worse is that you start an installation maybe with
the smaller loads and you pick a manufacturer of isolator and by time you get to the end they don't
actually make the range and that would bother my OCD in order that I could complete it using one
range and one range only and luden palace is only getting all that covered what else you're looking
for uh so i think obviously we think about current ratings but it's not just about currencies we're
thinking about what type of load makes up that current rating okay so pick this one up then
can you tell me on the side of it what type of loads that's looking to deal with okay so
on the side, I've got AC21 AC22 AC23 and then we'll start seeing kilowatt ratings over there
so what does that mean okay so let's have a look at the table then and look at those so you said AC
21 22 and 23 so we're looking at resistive loads including moderate overloads for 21 we're looking
at switching of mixed resistive and inductive loads including moderate overloads for 22
and AC23 is the switching of motor loads or highly inductive loads okay so again when we're thinking
about AC23 that's where a lot of products drop out of the drop out of the market because that's
that obviously that's the difficult one where you've got those inductive motors and transformers
so what else is on your wish list then okay so next thing i'm thinking about is cable room have
i got enough room inside there to terminate the conductors easily i'm saying some products on
the market might struggle in that area not a lot of room in there so let's have a look inside this
gary let's sort of bring that camera in oh we like a mechanism mechanism there so again if i
remove the instructions because i never read them um yes you can see there's lots of room in there
to bring cables up and around terminate them in what i also like as well is these are cage
type terminals okay so that's going to be that's kinder to the conductors as you bring them in
but obviously we're thinking on switches sometimes we're thinking just the pure current
carrying capacity yeah and that can be an issue in it because you could say oh i need 80 amps
however you could size a cable at 80 amps but there's some other considerations it could mean
the cable is a lot bigger Gordon isn't that yes I mean if there's thermal constraints or volt
drop and you've had to oversize the conductors you end up back here and you need to terminate
them into a terminal that might be a little bit smaller so you can have to bring in some copper
lug terminals there as well so they're going to need extra space and thankfully loads of space in
there so we'll look inside the switch fuse version here the metal version here oh nice mechanism like
a mechanism again we can see bags of space in there there is yes there's a little symbol there
that you always like to define for that and what does that symbol mean just to have a little uh
plenary on you yeah on onload on load switching and isolation okay yeah loads of room in there
yeah so i like that that's good so let's go back to that mechanism we said it was one action in
order to isolate it okay do you know why that is i don't know you're not you're going to tell
me there's some obscure regulation gary and that's why they have to be like that so let's have a look
at that then we're looking in four six five and in that regulation for emergency switching off we've
got the following the arrangement for emergency switching off shall be such that one single action
will only interrupt the appropriate supply okay so basically a quarter turn yes so one action
in order for emergency to interrupt the supply so we've got to do several different things in
order to turn off the supply so all of these here have that mechanism within them okay that's good
then the next thing i'm thinking about is the range of materials so sometimes i might want
to use a metal based isolator i might want to use a plastic isolator okay and even have grp
isolators as well okay just for those people out there tell them what grp stands for glass
reinforced plastic okay yeah sometimes called fiberglass but it's not fiberglasses perhaps the
repair in the car wing fiberglass but yeah i'm showing your ah gary cars don't rust these days
yeah so that yeah a huge range of bags of room lots of different types of materials to
cook with lots of different environments in which you might be installing it in
it doesn't stop there high ik ratings on these products as well um so again it's a pretty raw
bust if they're going to get knocked around you know depending on what type of installation you're
working in and while you're there you might want to be considering the ip rating of some
of these enclosures you want to have a look at some of these and give us those ip ranges
again we're back on the back on the label so we'll see we've got uh some minimum rating across
this range is ip65 okay so that's yeah that's you can use them in most outdoor environments
so we said these isolators could be used for isolation in other words allowing somebody to
work on the machinery and the one in front of us here gordon i've already introduced three
locking areas of which one of them also gives us the ability to have another six locks in there
so in order that we can work on that machine nice and safely yeah all right let's go i thought it
was like that bridge in paris where people chain all the locks to i thought you tried
to recreate that on the bench there's that many locks on it but let's have a look at this one in
a closer form and see where we can see when it's on and when it's off and the locking
points on this isolate here so i'm bringing the camera again you want to show me this one
so if you rotate that in the position what you're doing at the moment so that's on okay it's on in
that position and then tilt it there you can see we've got two lock off points on this variant
and also interesting to note as well you can't remove the switch so some of these isolators
you'll find a screw in the middle here and people can remove the handle of the isolator
even though it's in the off position uh yes even in the off position here so that i have seen it
and then also to remember as well these are interlocked as well so i can't uh in the in the
on position even though i've removed the screws i can't get the cover off do you want to prove that
again on that one that's an easier so this again this has a separate locking device there but even
on that case i can't be in the off position all right i've got one behind me here we need a hand
just to pop this on the bench and i want you okay it's currently in the uh on position i can't open
the door so that that rings through with what you've just said just uh just pull the mechanism
for me so in case i wanted to open the door gordon because remember your contractor this time
that was a hefty mechanism isn't it like a nice mechanism this is the 315 amp switch fuse from
luden and the good thing about luden if there's something in the range they don't have they're
quite willing to customize it to fit the exact needs of your project so as always me and the
the team from Lewden Palazzoli are interested in your comments please leave them below are you currently
fitting any of the range of isolators from Lewden Palazzoli are you thinking about fitting them in
the future is there something that you think is missing from their range and they would
benefit from having it please leave those comments below and we will get back to as many as we can