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Hello, welcome to this video. 

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Today, we're going to be doing a safe 

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disconnect on a Toyota Prius hybrid,
 which we have here beside of us.

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There are seven safe steps
 for disconnecting any

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electrical hybrid vehicle,
 and the seven steps are first one.

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We need to have clear 

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signage around the vehicle
 and on the vehicle and safety barriers

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showing other people
 that come into the workshop

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that is not to go near this vehicle
 unless they have either been trained,

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or that they're sure
 that it's safely shut down.

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The second step on
 this is to remove the key. 

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The reason for removing 

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the key is some of these have keyless
 entry and keyless start

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now being a hybrid vehicle. 

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What you find is that the
 when the battery voltage depletes

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slightly. This is sensed
 by the sensing module inside the car,

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and that will then energize the car
 to start the engine,

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to regenerate the battery,
 to recharge the battery.

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The last thing you want is to be working
 on this and it starts up on its own.

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So what we need to is remove the key
 we need at least three meters away.

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The reason for that is
 so that it doesn't restart the vehicle.

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The third step on
 this is to disconnect the low voltage,

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which is twelve volt battery in the car.
 So what we do is disconnect.

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The negative side of the battery
 always disconnect negative.

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So once that's loose, 

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we can disconnect the battery
 that's now disconnected.

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fourth thing you need to check
 is your PPE, so you need to

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check your gloves. You would need goggles
 if you were underneath the car.

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If you're not underneath the car,
 you won't need the goggles.

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As you can see on
 the bottom, here is a rubber mat.

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Whilst doing the low voltage side,
 you won't need to be on that.

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So this is the battery. 

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This the high voltage battery 

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here in the back of the Prius,
 which is located behind the rear seat.

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This orange plug here
 anything with an orange

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plug is high voltage
 anything orange cables.

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Brown cables is high voltage, so
 all we do is pull interlock up like that.

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Drop that down. And that's the interlock.

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So that is your interlock.
 That is your safe connector.

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So now the high voltage battery
 is now disconnected.

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So once you pull that, you
 then have to wait for step six,

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which is to wait five minutes,
 and that is for under the front here.

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There are some heavy duty capacitors
 and they need to discharge

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once they've discharged, which is what
 the safe disconnect is all about.

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We can then check the voltage
 to make sure that it's safe to do so.

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We've disconnected
 the interlock in the rear.

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We're now moving around to the front 

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and this is where
 we're going to look at the synergy drive. 

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So what we do is pop the bonnet up

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for this particular part of it,
 we don't have to use the high voltage mat

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and we can use normally non
 insulated tools.

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The reason for that
 is because this is accessible

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for the customer
 the customer can actually touch 

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all these nuts and bolts,
 and they can't be live

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otherwise you'd have dead
 customers or owners which isn't good.

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So I have already removed
 the plastic trim from here 

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and I've taken most of the bolts
 out of synergy unit.

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So what we do now is remove
 these two bolts. 

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I'm going to re check my gloves
 and we're going to go in

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and do the high voltage
 check on the front.

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So just these two bolts

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to wizz out. Again,

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checking for leaks, that one's okay,

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and the other glove, that's good.

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Making sure we're stood on the rubber
 insulated mat for extra safety.

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And then we can remove this lid,
 once you remove this lid,

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that then exposes
 all these high voltage components.

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Then the last one is after
 you've waited for five minutes.

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It is purely to get your multimetre
 and you need to check for low voltage,

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then check your high voltage for zero
 and then go back to your low voltage

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to make sure that that is definitely zero
 volts and is safe to work on.

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So we're on the meter
 we're set on DC volts.

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The reason for that 

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is because we're checking a twelve volt
 DC battery here and the hybrid battery.

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The high voltage battery is also DC volts,
 so you can leave the meter on DC volts

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for both of these tasks. 

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So we're going to start off
 with checking the small 

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auxiliary battery in the back,
 which is disconnected.

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So we're actually checking
 that the meter has got a reading

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or correctish reading of the voltage
 that is in that battery.

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Connect those on there, 

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and that's reading 12.057 volts
 okay, so we know the meter is now correct.

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So for this task, we don't need the PPE on
 because it's low voltage.

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So we're now going to move
 back to the front 

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and we will put the recheck our gloves,
 replace our gloves and then we can do

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the high voltage check . 

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So we've checked the voltage on the back,
 so we know the meter was reading correct.

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And now, because we're working on a high
 voltage, we need to retest our gloves.

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It's very, very important that every time
 these gloves are taken off,

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they are checked
 because if you get a pinhole there,

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when you're checking the high voltage 

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this end you will end up
 with an electric shock,

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which is something
 we don't want for anyone.

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Also, it's good to know that
 you really need someone else here with you

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when you're doing this task. 

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For the simple reason
 if I get electrocuted, 

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one of you guys is going to have to pull
 me off of that hook . Okay.

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So again, we're checking this glove
 this glove is all good.

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So pop our gloves on
 so we can do a high voltage check

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now when we check
 the little battery at the rear.

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We have one probe in each hand and
 we checked the terminals of the battery.

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That is a normal way
 of checking a low voltage battery.

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When working with high voltage,
 we need to do what's known

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as a chopstick method,
 and you hold the chopsticks in one hand.

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And the reason for that is
 electricity is very lazy

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and will take the shortest path. 

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So if you check them like that 

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and you get a short,
 the power will go through there,

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across your heart down there
 and you are now dead.

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Okay, no two ways about it.
 So what you do is do the chopstick method.

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So what will happen is if you get a short,
 it will go through this arm.

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It will knock you out. 

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You may squirm about the
 on the floor a little bit.

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The power will go down your leg to Earth
 and you will not die.

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You got more chance of survival.

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So it's very, very important
 to use the rubber mat. 

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These 17,000 volts insulate

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1000 volt insulated gloves
 and you use a chopstick method.

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So what we're going to do now 

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is we're going to now probe onto
 the positive and negative. Here of these

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cables coming into the 

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and we can see that
 the meter has gone to zero.

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So that is definitely on zero. 

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Now to confirm this,
 we need to go round the back

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and recheck the twelve volt battery. 

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And if we get battery voltage there,
 we can safely confirm that this unit,

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the capacitors have discharged,
 and is in a safe and stable condition

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to be able to work on. 

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Now what we're going to do
 is going to recheck this battery.

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We need to see battery voltage
 at this battery purely to confirm

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that the readings we had at
 the front was zero. 

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So by putting the positive on a positive
 and a negative on the negative,

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we should have 12.06
 on the battery voltage.

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So that's now confirmed that the system is
 shut down safely.

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There's no voltage
 between the battery here

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and the synergy drive in front,
 and all the capacitors in the synergy

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drive in the front are all now depleted,,
 so is now in a safe state to work on.

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You'll also notice that I'm no longer
 standing on the rubber mat

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because this is low voltage,
 not high voltage.

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You only need to stand on the rubber mat 

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and wear the gloves
 when dealing with high voltage. 

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And that concludes our video for today.