so for this video again still using a PIR but this time we're going to introduce the use of a um a
simple contactor and so in this case it's just going to be a single pole contactor again
we're not going to go into the detail of how the contactor works but we do need to be aware is that
there's two terminations here so if it's a single pole these would be labelled up as terminals
number one and number two and then we've got the coil connections and again that they would be A1
and A2 we have the PIR again which is the same and then we are just using one six amp circuit breaker
it's important also on the lighting circuit to say that it's just a small load going through this one
now remember without using a contactor the full load that's going through the
lights is also being switched through the PIR and in some cases um when these are operating so
there could be maybe three or four amps that also means that the three or four amps are going to be
are going to be being switched also through the PIR and i have known these PIRs to sometimes fail
because of this so a solution is just to introduce a contactor now in this case we are only going to
be using one six amp circuit breaker so again it's a small load the first things
we need to take neutrals to the relevant places so there's going to be a neutral going to the PIR
there's going to be a neutral going to the coil termination so A2 in this case
it could be A1 it doesn't matter and then also there's going to be a neutral to the lights
so from the circuit breaker we're going to take a live feed directly across the PIR
so at no point is the live feed interrupted there and also we're going to take another live feed
directly
to the contactor now this isn't a preferred method of mine to use i prefer to use two
circuit breakers but this method does work as well so i'm going to we'll go through this one first so
we've got a live feed coming up to the PIR and we also have a live feed coming on to the contactor
we also then need to have a feed that goes across to the lights and the only
thing that's missing now is the feed from the switch and that is going to operate
the coil
in this case terminals A1 so let's just look at this again so we have a six amp feed that's got a
permanent live feed go into the PIR and it's also got a permanent live feed going to the contactor
we obviously have our neutrals going how they are
and we then have our switch feed that's then controlling the coil
down to A1 and then we have our connection going across to the lights so let's look how it works
so somebody walks past the motion at the PIR
and their body is detected now what happens is this switch will close
so now we have a circuit not only to here and to here we now have a circuit
going through to the coil the coil becomes energized and pulls
down in that direction closing the contacts here making a bridge across terminals one and two
and as you can see then the lights will illuminate so i think that's quite a nice simple circuit
that shows how the use of one circuit breaker with a PIR and a contactor how that would operate
following on from the previous video using a contactor it's important
to note that the contactor needs to be rated again for the size of the load in
this case it's probably not that important but it should really be rated at the appropriate size
for the load this time on this circuit i'd also like to add in an
override switch and so again all that is is just a simple one way switch
one way switch
and again all we do is this switch needs to be in parallel with this switch
and as you can see like i said both switches are in parallel so now if this switch i showed you
previously with this switch being closed if this switch is now closed the circuit
then follows down through here down to the coil energizes the coil pulls the contactor down
makes a connection here and the lights come on
a PIR being operated with a contactor and an override switch